CHAPTER IX.

TOPICA.

I.

In treating of the Analytica Posteriora I have already adverted, in the way of contrast, to the Topica; and, in now approaching the latter work, I must again bring the same contrast before the mind of the reader.

The treatise called Topica (including that which bears the separate title De Sophisticis Elenchis, but which is properly its Ninth or last Book, winding up with a brief but memorable recapitulation of the Analytica and Topica considered as one scheme) is of considerable length, longer than the Prior and Posterior Analytics taken together. It contains both a theory and precepts of Dialectic; also, an analysis of the process called by Aristotle Sophistical Refutation, with advice how to resist or neutralize it.

All through the works of Aristotle, there is nothing which he so directly and emphatically asserts to be his own original performance, as the design and execution of the Topica: i.e., the deduction of Dialectic and Sophistic from the general theory of Syllogism. He had to begin from the beginning, without any model to copy or any predecessor to build upon: and in every sort of work, he observes justly, the first or initial stages are the hardest.1 In regard to Rhetoric much had been done before him; there were not only masters who taught it, but writers who theorized well or ill, and laid down precepts about it; so that, in his treatise on that subject, he had only to enlarge and improve upon pre-existing suggestions. But in regard to Dialectic as he conceives it — in its contrast with Demonstration and Science on the one hand, and in its analogy or kinship with Rhetoric on the other — nothing whatever had been done. There were, indeed, teachers of contentious dialogue, as well as of 263Rhetoric;2 but these teachers could do nothing better than recommend to their students dialogues or orations ready made, to be learnt by heart. Such a mode of teaching (he says), though speedy, was altogether unsystematic. The student acquired no knowledge of the art, being furnished only with specimens of art-results. It was as if a master, professing to communicate the art of making the feet comfortable, taught nothing about leather-cutting or shoe-making, but furnished his pupils with different varieties of ready-made shoes; thus supplying what they wanted for the protection of the feet, but not imparting to them any power of providing such protection for themselves.3 “In regard to the process of syllogizing (says Aristotle, including both Analytic and Dialectic) I found positively nothing said before me: I had to work it out for myself by long and laborious research.”4

This is one of the few passages, throughout the philosopher’s varied and multitudinous works, in which he alludes to his own speciality of method. It is all the more interesting on that account. If we turn back to Sokrates and Plato, we shall understand better what the innovation operated by Aristotle was; what the position of Dialectic had been before his time, and what it became afterwards.

In the minds of Sokrates and Plato, the great antithesis was between Dialectic and Rhetoric — interchange of short question and answer before a select audience, as contrasted with long continuous speech addressed to a miscellaneous crowd with known established sentiments and opinions, in the view of persuading them on some given interesting point requiring decision. In such Dialectic Sokrates was a consummate master; passing most of his long life in the market-place and palæstra, and courting disputation with every one. He made formal profession of ignorance, disclaimed all power of teaching, wrote nothing at all, and applied himself almost exclusively to the cross-examining Elenchus by which he exposed and humiliated the ablest men not less than the vulgar. Plato, along with the other companions of Sokrates, imbibed the Dialectic of his master, and gave perpetuity to it in those inimitable dialogues which are still 264preserved to us from his pen. He composed nothing but dialogues; thus giving expression to his own thoughts only under borrowed names, and introducing that of Sokrates very generally as chief spokesman. But Plato, though in some dialogues he puts into the mouth of his spokesman the genuine Sokratic disclaimer of all power and all purpose of teaching, yet does not do this in all. He sometimes assumes the didactic function; though he still adheres to the form of dialogue, even when it has become inconvenient and unsuitable. In the Platonic Republic Sokrates is made to alternate his own peculiar vein of cross-examination with a vein of dogmatic exposition not his own; but both one and the other in the same style of short question and answer. In the Leges becomes still more manifest the inconvenience of combining the substance of dogmatic exposition with the form of dialogue: the same remark may also be made about the Sophistes and Politicus; in which two dialogues, moreover, the didactic process is exhibited purely and exclusively as a logical partition, systematically conducted, of a genus into its component species. Long-continued speech, always depreciated by Plato in its rhetorical manifestations, is foreign to his genius even for purposes of philosophy: the very lecture on cosmogony which he assigns to Timæus, and the mythical narrative (unfinished) delivered by Kritias, are brought into something like the form of dialogue by a prefatory colloquy specially adapted for that end.

It thus appears that, while in Sokrates the dialectic process is exhibited in its maximum of perfection, but disconnected altogether from the didactic, which is left unnoticed, — in Plato the didactic process is recognized and postulated, but is nevertheless confounded with or absorbed into the dialectic, and admitted only as one particular, ulterior, phase and manifestation of it. At the same time, while both Sokrates and Plato bring out forcibly the side of antithesis between Rhetoric and Dialectic, they omit entirely to notice the side of analogy or parallelism between them. On both these points Aristotle has corrected the confusion, and improved upon the discrimination, of his two predecessors. He has pointedly distinguished the dialectic process from the didactic; and he has gone a step farther, furnishing a separate theory and precepts both for the one and for the other. Again, he has indicated the important feature of analogy between Dialectic and Rhetoric, in which same feature both of them contrast with Didactic — the point not seized either by Sokrates or by Plato.

Plato, in his Sokratic dialogues or dialogues of Search, has 265given admirable illustrative specimens of that which Sokrates understood and practised orally as Dialectic. Aristotle, in his Topica, has in his usual vein of philosophy theorized on this practice as an art. He had himself composed dialogues, which seem as far as we can judge from indirect and fragmentary evidence, to have been Ciceronian or rhetorical colloquies — a long pleading pro followed by a long pleading con, rather than examples of Sokratic brachylogy and cross-examination. But his theory given in the Topica applies to genuine Sokratic fencing, not to the Ciceronian alternation of set speeches. He disallows the conception of Plato, that Dialectic is a process including not merely dispute but all full and efficacious employment of general terms and ideas for purposes of teaching: he treats this latter as a province by itself, under the head of Analytic: and devotes the Topica to the explanation of argumentative debate, pure and simple. He takes his departure from the Syllogism, as the type of deductive reasoning generally; the conditions under which syllogistic reasoning is valid and legitimate, having been already explained in his treatise called Analytica Priora. So obtained, and regulated by those conditions, the Syllogism may be applied to one or other of two distinct and independent purposes:— (1) To Demonstration or Scientific Teaching, which we have had before us in the last two chapters, commenting on the Analytica Posteriora; (2) To Dialectic, or Argumentative Debate, which we are now about to enter on in the Topica.

The Dialectic Syllogism, explained in the Topica, has some points in common with the Demonstrative Syllogism, treated in the Analytica Posteriora. In both, the formal conditions are the same, and the conclusions will certainly be true, if the premisses are true; in both, the axioms of deductive reasoning are assumed, namely, the maxims of Contradiction and Excluded Middle. But, in regard to the subject-matter, the differences between them are important. The Demonstrative Syllogism applies only to a small number of select sciences, each having special principia of its own, or primary, undemonstrable truths, obtained in the first instance by induction from particulars. The premisses being thus incontrovertibly certain, the conclusions deduced are not less certain; there is no necessary place for conflicting arguments or counter-syllogisms, although in particular cases paralogisms may be committed, and erroneous propositions or majors for syllogism may be assumed. On the contrary, the Dialectic Syllogism applies to all matters without exception; the premisses on which it proceeds are neither 266obtained by induction, nor incontrovertibly certain, but are borrowed from some one among the varieties of accredited or authoritative opinion. They may be opinions held by the multitude of any particular country, or by an intelligent majority, or by a particular school of philosophers or wise individuals, or from transmission as a current proverb or dictum of some ancient poet or seer. From any one of these sources the dialectician may borrow premisses for syllogizing. But it often happens that the premisses which they supply are disparate, or in direct contradiction to each other; and none of them is entitled to be considered as final or peremptory against the rest. Accordingly, it is an essential feature of Dialectic as well as of Rhetoric that they furnish means of establishing conclusions contrary or contradictory, by syllogisms equally legitimate.5 The dialectic procedure is from its beginning intrinsically contentious, implying a debate between two persons, one of whom sets up a thesis to defend, while the other impugns it by interrogation: the assailant has gained his point, if he can reduce the defendant to the necessity of contradicting himself; while the defendant on his side has to avoid giving any responses which may drive him to the necessity of such contradiction.

Aristotle takes great pains to enforce the separation both of Dialectic and Rhetoric from Science or Instruction with its purpose of teaching or learning. He disapproves of those (seemingly intending Plato) who seek to confound the two. Dialectic and Rhetoric (he says) have for their province words and discourse, not facts or things: they are not scientific or didactic processes, but powers or accomplishments of discourse; and whoever tries to convert them into means of teaching or learning particular subjects, abolishes their characteristic feature and restricts their universality of application.6 Both of them deal not with scientific facts, but with the sum total of accredited opinions, though each for its own purpose: both of them lay hold of any one among the incoherent aggregate of accepted generalities, suitable for the occasion; the Dialectician trying 267to force his opponent into an inconsistency, the Rhetor trying to persuade his auditors into a favourable decision. Neither the one nor the other goes deeper than opinion for his premisses, nor concerns himself about establishing by induction primary or special principia, such as may serve for a basis of demonstration.

In every society there are various floating opinions and beliefs, each carrying with it a certain measure of authority, often inconsistent with each other, not the same in different societies, nor always the same even in the same society. Each youthful citizen, as he grows to manhood, imbibes these opinions and beliefs insensibly and without special or professional teaching.7 The stock of opinions thus transmitted would not be identical even at Athens and Sparta: the difference would be still greater, if we compared Athens with Rome, Alexandria, or Jerusalem. Such opinions all carry with them more or less of authority, and it is from them that the reasonings of common life, among unscientific men, are supplied. The practice of dialectical discussion, prevalent in Athens during and before the time of Aristotle, was only a more elaborate, improved, and ingenious exhibition of this common talk; proceeding on the same premisses, but bringing them together from a greater variety of sources, handling them more cleverly, and having for its purpose to convict an opponent of inconsistency. The dialecticians dwelt exclusively in the region of these received opinions; and the purpose of their debates was to prove inconsistency, or to repel the proof of inconsistency, between one opinion and another.

This dialectic debate, which Aristotle found current at Athens, he tries in the Topica to define and reduce to system. The dialectician must employ Syllogism; and we are first taught to distinguish the Syllogism that he employs from others. The Dialectic syllogism is discriminated on one side from the Demonstrative, on the other from the Eristic (or litigious); also from the scientific Paralogism or Pseudographeme. This discrimination is founded on the nature of the evidence belonging to the premisses. The Demonstrative syllogism (which we have already gone through in the Analytica Posteriora) has premisses noway dependent upon opinion: it deduces conclusions from true first principles, obtained by Induction in each science, and 268different in each different science. The Dialectic syllogism does not aspire to any such evidence, but borrows its premisses from Opinion of some sort; accredited either by numbers, or by wise individuals, or by some other authoritative holding. As this evidence is very inferior to that of the demonstrative syllogism, so again it is superior to that of the third variety — the Eristic syllogism. In this third variety,8 the premisses do not rest upon any real opinion, but only on a fallacious appearance or simulation of opinion; insomuch that they are at once detected as false, by any person even of moderate understanding; whereas (according to Aristotle) no real opinion ever carries with it such a merely superficial semblance, or is ever so obviously and palpably false. A syllogism is called Eristic also when it is faulty in form, though its premisses may be borrowed from real opinion, or when it is both faulty in form and false in the matter of the premisses. Still a fourth variety of syllogism is the scientific Paralogism: where the premisses are not borrowed from any opinion, real or simulated, but belong properly to the particular science in which they are employed, yet nevertheless are false or erroneous.9

Upon the classification of syllogisms here set forth by Aristotle, we may remark that the distinction between the Demonstrative and the Dialectic is true and important; but that between the Dialectic and the Eristic is faint and unimportant; the class called Eristic syllogisms being apparently introduced merely to create a difference, real or supposed, between the Dialectician and the Sophist, and thus to serve as a prelude to the last book of this treatise, entitled Sophistici Elenchi. The class-title Eristic (or litigious) is founded upon a supposition of dishonest intentions on the part of the disputant; but it is unphilosophical to make this the foundation of a class, and to rank the same syllogism in the class, or out of it, according as the intentions of the disputant who employs it are honest or dishonest. Besides, a portion of Aristotle’s definition tells us that the Eristic syllogism is one of which the premisses can impose upon no one; being such that a very ordinary man can at once detect their falsity. The dishonest disputant, surely, would argue to little purpose, if he intentionally employed such premisses as these. Lastly, according to another portion of 269Aristotle’s definition, every syllogism faulty in form, or yielding no legitimate conclusion at all, will fall under the class Eristic, and this he himself in another place explicitly states;10 which would imply that the bad syllogism must always emanate from litigious or dishonest intentions. But in defining the Pseudographeme, immediately afterwards, Aristotle does not imply that the false scientific premiss affords presumption of litigious disposition on the part of those who advance it; nor does there seem any greater propriety in throwing all bad dialectic syllogisms under the general head of Eristic.

The dialectician, then, will carry on debate only by means of premisses sustained by real opinion; which not only always carry some authority, but are assumed as being never obviously fallacious; though often inconsistent with each other, and admitting of argumentation pro and con. These are what Aristotle calls Endoxa; opposed to Adoxa, or propositions which are discountenanced, or at least not countenanced, by opinion, and to Paradoxa (a peculiar variety of Adoxa),11 or propositions which, though having ingenious arguments in their favour, yet are adverse to some proclaimed and wide-spread opinions, and thus have the predominant authority of opinion against them.

Of these three words, Paradox is the only one that has obtained a footing in modern languages, thanks to Cicero and the Latin authors. If the word Endox had obtained the like footing, we should be able to keep more closely to the thought and views of Aristotle. As it is, we are obliged to translate the Greek Endoxon as Probable, and Adoxon as Improbable:12 which, though not incorrect, is neither suitable nor exactly coincident. Probable corresponds more nearly to what Aristotle (both in this treatise and in the Analytica) announces sometimes as τὸ ὡς ἐπὶ τὸ πολύ — that which happens in most cases but not in all, as distinguished from the universal and necessary on one side, and from the purely casual on the other;13 sometimes, also, as τὸ εἰκός or τὸ σημεῖον. Now this is a different idea from (though it has a point of analogy with) the Endoxon: which is not necessarily true even in part, but may be wholly untrue; which always has some considerations against it, though there 270may be more in its favour; and which, lastly, may be different, or even opposite, in different ages and different states of society. When Josephus distinguished himself as a disputant in the schools of Jerusalem on points of law and custom,14 his arguments must have been chiefly borrowed from the Endoxa or prevalent opinions of the time and place; but these must have differed widely from the Endoxa found and argued upon by the contemporaries of Aristotle at Athens. The Endoxon may indeed be rightly called probable, because, whenever a proposition is fortified by a certain body of opinion, Aristotle admits a certain presumption (greater or less) that it is true. But such probability is not essential to the Endoxon: it is only an accident or accompaniment (to use the Aristotelian phrase), and by no means an universal accompaniment. The essential feature of the Endoxon is, that it has acquired a certain amount of recognition among the mass of opinions and beliefs floating and carrying authority at the actual time and place. The English word whereby it is translated ought to express this idea, and nothing more; just as the correlative word Paradox does express its implication, approached from the other side. Unfortunately, in the absence of Endox, we have no good word for the purpose.

It is within this wide field of floating opinions that dialectical debate and rhetorical pleading are carried on. Dialectic supposes a questioner or assailant, and a respondent or defendant. The respondent selects and proclaims a problem or thesis, which he undertakes to maintain: the assailant puts to him successive questions, with the view of obtaining concessions which may serve as premisses for a counter-syllogism, of which the conclusion is contradictory or contrary to the thesis itself, or to some other antecedent premiss which the respondent has already conceded. It is the business of the respondent to avoid making any answers which may serve as premisses for such a counter-syllogism. If he succeeds in this, so as not to become implicated in any contradiction with himself, he has baffled his assailant, and gained the victory. There are, however, certain rules and conditions, binding on both parties, under which the debate must be carried on. It is the purpose of the Topica to indicate these rules; and, in accordance therewith, to advise both parties as to the effective conduct of their respective cases—as to the best thrusts and the best mode of parrying. The assailant is supplied with a classified catalogue of materials for questions, and with indications of the weak points which he is 271to look out for in any new subject which may turn up for debate. He is farther instructed how to shape, marshal, and disguise his questions, in such a way that the respondent may least be able to foresee their ultimate bearing. The respondent, on his side, is told what he ought to look forward to and guard against. Such is the scope of the present treatise; the entire process being considered in the large and comprehensive spirit customary with Aristotle, and distributed according to the Aristotelian terminology and classification.

It is plain that neither the direct purpose of the debaters, nor the usual result of the debate, is to prove truth or to disprove falsehood. Such may indeed be the result occasionally; but the only certain result is, that an inconsistency is exposed in the respondent’s manner of defending his thesis, or that the assailant fails in his purpose of showing up such inconsistency. Whichever way the debate may turn, no certain inference can be drawn as to the thesis itself: not merely as to whether it is true or false, but even as to whether it consists or does not consist with other branches of received opinions. Such being the case, what is the use or value of dialectic debate, or of a methodized procedure for conducting it? Aristotle answers this question, telling us that it is useful for three purposes.15 First, the debate is a valuable and stimulating mental exercise; and, if a methodized procedure be laid down, both parties will be able to conduct it more easily as well as more efficaciously. Secondly, it is useful for our intercourse with the multitude;16 for the procedure directs us to note and remember the opinions of the multitude, and such knowledge will facilitate our intercourse with them: we shall converse with them out of their own opinions, which we may thus be able beneficially to modify. Thirdly, dialectic debate has an useful though indirect bearing even upon the processes of science and philosophy, and upon the truths thereby acquired.17 For it accustoms us to study the difficulties on both sides of every question, and thus assists us in detecting and discriminating truth and falsehood. Moreover, apart from this mode of usefulness, it opens a new road to the scrutiny of the first principia of each separate science. These principia can never be scrutinized through the truths of 272the science itself, which presuppose them and are deduced from them. To investigate and verify them, is the appropriate task of First Philosophy. But Dialectic also, carrying investigation as it does everywhere, and familiarized with the received opinions on both sides of every subject, suggests many points of importance in regard to these principia.

The three heads just enumerated illustrate the discriminating care of Aristotle. The point of the first head is brought out often in the Platonic Dialogues of Search: the stimulus brought to bear in awakening dormant intellectual power, and in dissipating that false persuasion of knowledge which is the general infirmity of mankind, is frequently declared by Plato to be the most difficult, but the indispensable, operation of the teacher upon his pupil. Under the third head, Aristotle puts this point more justly than Plato, not as a portion of teaching, nor as superseding direct teaching, but as a preliminary thereunto; and it is a habit of his own to prefix this antecedent survey of doubts and difficulties on both sides, as a means of sharpening our insight into the dogmatic exposition which immediately follows.

Under the second head, we find exhibited another characteristic feature of Aristotle’s mind — the value which he sets upon a copious acquaintance with received opinions, whether correct or erroneous. The philosophers of his day no longer talked publicly in the market-place and with every one indiscriminately, as Sokrates had done: scientific study, and the habit of written compositions naturally conducted them into a life apart, among select companions. Aristotle here indicates that such estrangement from the multitude lessened their means of acting beneficially on the multitude, and in the way of counteraction he prescribes dialectical exercise. His own large and many-sided observation, extending to the most vulgar phenomena, is visible throughout his works, and we know that he drew up a collection of current proverbs.18

Again, what we read under the third head shows that, while Aristotle everywhere declares Demonstration and teaching to be a process apart from Dialectic, he at the same time recognizes the legitimate function of the latter, for testing and verifying the principia of Demonstration:19 which principia cannot be 273reached by Demonstration itself, since every demonstration presupposes them. He does not mean that these principia can be proved by Dialectic, for Dialectic does not prove any thing; but it is necessary as a test or scrutinizing process to assure us that all the objections capable of being offered against them can be met by sufficient replies. In respect of universal competence and applicability, Dialectic is the counterpart, or rather the tentative companion and adjunct, of what Aristotle calls First Philosophy or Ontology; to which last he assigns the cognizance of principia as we shall see when we treat of the Metaphysica.20 Dialectic (he repeats more than once) is not a definite science or body of doctrine, but, like rhetoric or medicine, a practical art or ability of dealing with the ever varying situations of the dialogue; of imagining and enunciating the question proper for attack, or the answer proper for defence, as the case may be. As in the other arts, its resources are not unlimited. Nor can the dialectician, any more than the rhetor or the physician, always guarantee success. Each of them has an end to be accomplished; and if he employs for its accomplishment the best means that the situation permits, he must be considered a master of his own art and procedure.21 To detect truth, and to detect what is like truth, belong (in Aristotle’s judgment) to the same mental capacity. Mankind have a natural tendency towards truth, and the common opinions therefore are, in most cases, coincident with truth. Accordingly, the man who divines well in regard to verisimilitude, will usually divine well in regard to truth.22

The subject-matter of dialectic debate, speaking generally, consists of Propositions and Problems, to be propounded as questions by the assailant and to be admitted or disallowed by the defendant. They will relate either to Expetenda and Fugienda, or they must bear, at least indirectly, upon some point of scientific truth or observed cognition.23 They will be either ethical, physical, or logical; class-terms which Aristotle declines to define, contenting himself with giving an example to illustrate each of them, while adding that the student should collect other 274similar examples, and gradually familiarize himself with the full meaning of the general term, through such inductive comparison of particulars.24

But it is not every problem coming under one of these three heads that is fit for dialectic debate. If a man propounds as subject for debate, Whether we ought to honour the gods or to love our parents, he deserves punishment instead of refutation: if he selects the question, Whether snow is white or not, he must be supposed deficient in perceptive power.25 What all persons unanimously believe, is unsuitable:26 what no one believes is also unsuitable, since it will not be conceded by any respondent. The problem must have some doubts and difficulties, in order to afford scope for discussion; yet it must not be one of which the premisses are far-fetched or recondite, for that goes beyond the limits of dialectic exercise.27 It ought to be one on which opinions are known to be held, both in the affirmative and in the negative; on which either the multitude differ among themselves, the majority being on one side, while yet there is an adverse minority; or some independent authority stands opposed to the multitude, such as a philosopher of eminence, a professional man or artist speaking on his own particular craft, a geometer or a physician on the specialities of his department. Matters such as these are the appropriate subjects for dialectic debate; and new matters akin to them by way of analogy may be imagined and will be perfectly admissible.28 Even an ingenious paradox or thesis adverse to prevailing opinions may serve the purpose, as likely to obtain countenance from some authority, though as yet we know of none.29

275These conditions apply both to problems propounded for debate, and to premisses tendered on either side during the discussion. Both the interrogator and the respondent — the former having to put appropriate questions, and the latter to make appropriate answers — must know and keep in mind these varieties of existing opinion among the multitude as well as among the special dissident authorities above indicated. The dialectician ought to collect and catalogue such Endoxa, with the opinions analogous to them, out of written treatises and elsewhere;30 distributing them under convenient heads, such as those relating to good and evil generally, and to each special class of good, &c. Aristotle, however, admonishes him that he is debating problems not scientifically, but dialectically: having reference not to truth, but to opinion.31 If the interrogator were proceeding scientifically and didactically, he would make use of all true and ascertained propositions, whether the respondent conceded them or not, as premisses for his syllogism. But in Dialectic he is dependent on the concession of the respondent, and can construct his syllogisms only from premisses that have been conceded to him.32 Hence he must keep as closely as he can to opinions carrying extrinsic authority, as being those which the respondent will hesitate to disallow.33

Moreover, the form of the interrogation admissible in dialectic debate is peculiar. The respondent is not bound to furnish any information in his answer: he is bound only to admit, or to deny, a proposition tendered to him. You must not ask him, What is the genus of man? You must yourself declare the genus, and ask whether he admits it, in one or other of the two following forms — (1) Is animal the genus of man? (2) Is animal the genus of man, or not? to which the response is an admission or a denial.34

Dialectic procedure, both of the assailant and of the defendant,276 has to do with propositions and problems; accordingly, Aristotle introduces a general distribution of propositions under four heads. The predicate must either be Genus, or Proprium, or Accident, of its subject. But the Proprium divides itself again into two. It always reciprocates with, or is co-extensive with, its subject; but sometimes it declares the essence of the subject, sometimes it does not. When it declares the essence of the subject, Aristotle calls it the Definition; when it does not declare the essence of the subject, although reciprocating therewith, he reserves for it the title of Proprium. Every proposition, and every problem, the entire material of Dialectic, will declare one of these four — Proprium, Definition, Genus, or Accident.35 The Differentia, as being attached to the Genus, is ranked along with the Genus.36

The above four general heads include all the Predicables, which were distributed by subsequent logicians (from whom Porphyry borrowed) into five heads instead of four — Genus, Species, Differentia, Proprium, Accident; the Differentia being ranked as a separate item in the quintuple distribution, and the Species substituted in place of the Definition. It is under this quadruple classification that Aristotle intends to consider propositions and problems as matters for dialectic procedure: he will give argumentative suggestions applicable to each of the four successively. It might be practicable (he thinks) to range all the four under the single head of Definition; since arguments impugning Genus, Proprium, and Accident, are all of them good also against Definition. But such a simplification would be perplexing and unmanageable in regard to dialectic procedure.37

That the quadruple classification is exhaustive, and that every proposition or problem falls under one or other of the four heads, may be shown in two ways. First, by Induction: survey and analyse as many propositions as you will, all without exception will be found to belong to one of the four.38 Secondly, by the following Deductive proof:— In every proposition the predicate is either co-extensive and reciprocating with the subject, or it is not. If it does reciprocate, it either declares the essence of the subject, or it does not: if the former, it is the Definition; if the latter, it is a Proprium. But, supposing the predicate not 277to reciprocate with the subject, it will either declare something contained in the Definition, or it will not. If it does contain a part of the Definition, that part must be either a Genus or a Differentia, since these are the constituents of the Definition. If it does not contain any such part, it must be an Accident.39 Hence it appears that every proposition must belong to one or other of the four, and that the classification is exhaustive.

Moreover, each of the four Predicables must fall under one or other of the ten Categories or Predicaments. If the predicate be either of Genus or Definition, declaring the essence of the subject, it may fall under any one of the ten Categories; if of Proprium or Accident, not declaring essence, it cannot belong to the first Category (Οὐσία), but must fall under one of the remaining nine.40

The notion of Sameness or Identity occurs so often in dialectic debate, that Aristotle discriminates its three distinct senses or grades: (1) Numero; (2) Specie; (3) Genere. Water from the same spring is only idem specie, though the resemblance between two cups of water from the same spring is far greater than that between water from different sources. Even Idem Numero has different significations: sometimes there are complete synonyms; sometimes an individual is called by its proprium, sometimes by its peculiar temporary accident.41

Having thus classified dialectic propositions, Aristotle proceeds to the combination of propositions, or dialectic discourse and argument. This is of two sorts, either Induction or Syllogism; of both which we have already heard in the Analytica. Induction is declared to be plainer, more persuasive, nearer to sensible experience, and more suitable to the many, than Syllogism; while this latter carries greater compulsion and is more irresistible against professed disputants.42 A particular example is given to illustrate what Induction is. But we remark that though it is always mentioned as an argumentative procedure important and indispensable, yet neither here nor elsewhere does Aristotle go into any discriminative analysis of the conditions278 under which it is valid, as he does about Syllogism in the Analytica Priora.

What helps are available to give to the dialectician a ready and abundant command of syllogisms? Four distinct helps may be named:43 (1) He must make a large collection of Propositions; (2) He must study and discriminate the different senses in which the Terms of these propositions are used; (3) He must detect and note Differences; (4) He must investigate Resemblances.

1. About collecting Propositions, Aristotle has already indicated that those wanted are such as declare Endoxa, and other modes of thought cognate or analogous to the Endoxa:44 opinions of the many, and opinions of any small sections or individuals carrying authority. All such are to be collected (out of written treatises as well as from personal enquiry); nor are individual philosophers (like Empedokles) to be omitted, since a proposition is likely enough to be conceded when put upon the authority of an illustrious name.45 If any proposition is currently admitted as true in general or in most cases, it must be tendered with confidence to the respondent as an universal principle; for he will probably grant it, not being at first aware of the exceptions.46 All propositions must be registered in the most general terms possible, and must then be resolved into their subordinate constituent particulars, as far as the process of subdivision can be carried.47

2. The propositions having been got together, they must be examined in order to find out Equivocation or double meaning of terms. There are various ways of going about this task. Sometimes the same predicate is applied to two different subjects, but in different senses; thus, courage and justice are both of them good, but in a different way. Sometimes the same predicate is applied to two different classes of subjects, each admitting of being defined; thus, health is good in itself, and exercise is 279good as being among those things that promote health.48 Sometimes the equivocal meaning of a term is perceived by considering its contrary; if we find that it has two or more distinct contraries, we know at once that it has different meanings. Sometimes, though there are not two distinct contraries, yet the mere conjunction of the same adjective with two substantives shows us at once that it cannot mean the same in both49 (λευκὴ φωνή — λευκὸν χρῶμα). In one sense, the term may have an assignable contrary, while in another sense it may have no contrary; showing that the two senses are distinct: for example, the pleasure of drinking has for its contrary the pain of thirst; but the pleasure of scientifically contemplating that the diagonal of a square is incommensurable with the side, has no contrary; hence, we see that pleasure is an equivocal term.50 In one sense, there may be a term intermediate between the two contraries; in another sense, there may be none; or there may be two distinct intermediate terms for the two distinct senses; or there may be several intermediate terms in one of the senses, and only one or none in the other: in each of these ways the equivocation is revealed.51 We must look also to the contradictory opposite (of a term), which may perhaps have an obvious equivocation of meaning; thus, μὴ βλέπειν means sometimes to be blind, sometimes not to be seeing actually, whence we discover that βλέπειν also has the same equivocation.52 If a positive term is equivocal, we know that the privative term correlating with it must also be equivocal; thus, τὸ αἰσθάνεσθαι has a double sense, according as we speak with reference to mind or body; and this will be alike true of the correlating privative — τὸ ἀναίσθητον εἶναι.53 Farther, an equivocal term will have its derivatives equivocal in the same manner; and conversely, if the derivative be equivocal, the radical will be so likewise.54 The term must also be looked at in reference to the ten Categories: if its meanings fall under more than one Category, we know that it is equivocal.55 If it comprehends two subjects which are not in the same genus, or in genera not subordinate one to the other, this too will show that it is equivocal.56 The contrary, also, of the term must be looked at with a view to the same inference.57

Again, it will be useful to bring together the same term in two 280different conjunctions, and to compare the definitions of the two. Define both of them, and then deduct what is peculiar to each definitum: if the remainder be different, the term will be equivocal; if the remainder be the same, the term will be univocal. Thus, λευκὸν σῶμα will be defined, a body having such and such a colour: λευκὴ φωνή, a voice easily and distinctly heard: deduct σῶμα from the first definition, and φωνὴ from the second, the remainder will be totally disparate; therefore, the term λευκόν is equivocal.58 Sometimes, also, the ambiguity may be found in definitions themselves, where the same term is used to explain subjects that are not the same; whether such use is admissible, has to be considered.59 If the term be univocal, two conjunctions of it may always be compared as to greater or less, or in respect of likeness; whenever this cannot be, the term is equivocal.60 If, again, the term is used as a differentia for two genera quite distinct and independent of each other, it must be equivocal; for genera that are unconnected and not subordinate one to the other, have their differentiæ also disparate.61 And, conversely, if the term be such that the differentiæ applied to it are disparate, we may know it to be an equivocal term. The like, if the term be used as a species in some of its conjunctions, and as a differentia in others.62

3. Aristotle has thus indicated, at considerable length, the points to be looked for when we are examining whether a term is univocal or equivocal. He is more concise when he touches on the last two out of the four helps (ὄργανα) enumerated for supplying syllogisms when needed, — viz. the study of Differences and of Resemblances. In regard to the study of Differences, standing third, while he remarks that, where these are wide and numerous, they are sure without any precept to excite our attention, he advises that we should study the differences of subjects that are nearly allied, — those within the same genus, or comprehended in genera not much removed from one another, such as, the distinction between sensible perception and science. But he goes into no detail.62

4. In regard to the study of Resemblances, he inverts the above precept, and directs us to note especially the points of resemblance between subjects of great apparent difference.63 We must examine what is the quality common to all species of the 281same genus — man, horse, dog, &c.; for it is in this that they are similar. We may also compare different genera with each other, in respect to the analogies that are to be found in each: e.g., as science is to the cognizable, so is perception to the perceivable; as sight is in the eye, so is intellection in the soul; as γαλήνη is in the sea, so is νηνεμία in the air.64

Such are the four distinct helps, towards facility of syllogizing, enumerated by Aristotle. It will be observed that the third and fourth (study of Resemblances and Differences) bear more upon matters of fact and less upon words; while the second (τὸ ποσαχῶς), though doubtless also bearing on matters of fact and deriving from thence its main real worth, yet takes its departure from terms and propositions, and proceeds by comparing multiplied varieties of these in regard to diversity of meaning. Upon this ground it is, apparently, that Aristotle has given so much fuller development to the second head than to the third and fourth; for, in the Topica, he is dealing with propositions and counter-propositions — with opinions and counter-opinions, not with science and truth.

He proceeds to indicate the different ways in which these three helps (the second, third, and fourth) further the purpose of the dialectician — respondent as well as assailant. Unless the different meanings of the term be discriminated, the respondent cannot know clearly what he admits or what he denies; he may be thinking of something different from what the assailant intends, and the syllogisms constructed may turn upon a term only, not upon any reality.65 The respondent will be able to protect himself better against being driven into contradiction, if he can distinguish the various meanings of the same term; for he will thus know whether the syllogisms brought against him touch the real matter which he has admitted.66 On the other hand, the assailant will have much facility in driving his opponent into contradiction, if he (the assailant) can distinguish the different meanings of the term, while the respondent cannot do so; in those cases at least where the proposition is true in one sense of the term and false in another.67 This manner of proceeding, however, is hardly consistent with genuine Dialectic. No dialectician ought ever to found his interrogations and his 282arguments upon a mere unanalysed term, unless he can find absolutely nothing else to say in the debate.68

The third help (an acquaintance with Differences) will be of much avail on all occasions where we have to syllogize upon Same and Different, and where we wish to ascertain the essence or definition of any thing; for we ascertain this by exclusion of what is foreign thereunto, founded on the appropriate differences in each case.69

Lastly, the fourth help (the intelligent survey of Resemblances) serves us in different ways:— (1) Towards the construction of inductive arguments; (2) Towards syllogizing founded upon assumption; (3) Towards the declaration of definitions. As to the inductive argument, it is founded altogether on a repetition of similar particulars, whereby the universal is obtained.70 As to the syllogizing from an assumption, the knowledge of resemblances is valuable, because we are entitled to assume, as an Endoxon or a doctrine conformable to common opinion, that what happens in any one of a string of similar cases will happen also in all the rest. We lay down this as the major proposition of a syllogism; and thus, if we can lay hold of any one similar case, we can draw inference from it to the matter actually in debate.71 Again, as to the declaration of definitions, when we have once discovered what is the same in all particular cases, we shall have ascertained to what genus the subject before us belongs;72 for that one of the common predicates which is most of the essence, will be the genus. Even where the two matters compared are more disparate than we can rank in the same genus, the knowledge of resemblances will enable us to discover useful analogies, and thus to obtain a definition at least approximative. Thus, as the point is in a line, so is the unit in numbers; each of them is a principium; this, therefore, is a common genus, which will serve as a tolerable definition. Indeed this is the definition of them commonly given by philosophers; who call the unit principium of number, and the point 283principium of a line, thus putting one and the other into a genus common to both.73

II.

The First Book of the Topica, which we have thus gone through, was entitled by some ancient commentators τὰ πρὸ τῶν Τόπων — matters preliminary to the Loci. This is quite true, as a description of its contents; for Aristotle in the last words of the book, distinctly announces that he is about to enumerate the Loci towards which the four above-mentioned Organa will be useful.74

Locus (τόπος) is a place in which many arguments pertinent to one and the same dialectical purpose, may be found — sedes argumentorum. In each locus, the arguments contained therein look at the thesis from the same point of view; and the locus implies nothing distinct from the arguments, except this manner of view common to them all. In fact, the metaphor is a convenient one for designating the relation of every Universal generally to its particulars: the Universal is not a new particular, nor any adjunct superimposed upon all its particulars, but simply a place in which all known similar particulars may be found grouped together, and in which there is room for an indefinite number of new ones. If we wish to arm the student with a large command of dialectical artifices, we cannot do better than discriminate the various groups of arguments, indicating the point of view common to each group, and the circumstances in which it becomes applicable. By this means, whenever he is called upon to deal with a new debate, he will consider the thesis in reference to each one of these different loci, and will be able to apply arguments out of each of them, according as the case may admit.

The four Helps (ὄργανα) explained in the last book differ from the Loci in being of wider and more undefined bearing: they are directions for preparatory study, rather than for dealing with any particular situation of a given problem; though it must be confessed that, when Aristotle proceeds to specify the manner in which the three last-mentioned helps are useful, he makes considerable approach towards the greater detail and particularization284 of the Loci. In entering now upon these, he reverts to that quadruple classification of propositions and problems (according to the four Predicables), noted at the beginning of the treatise, in which the predicate is either Definition, Proprium, Genus, or Accident, of the subject. He makes a fourfold distribution of Loci, according as they bear upon one or other of these four. In the Second and Third Books, we find those which bear upon propositions predicating Accident; in the Fourth Book, we pass to Genus; in the Fifth, to Proprium; in the Sixth and Seventh, to Definition.

The problem or thesis propounded for debate may have two faults on which it may be impugned: either it may be untrue; or it may be expressed in a way departing from the received phraseology.75 It will be universal, or particular, or indefinite; and either affirmative or negative; but, in most cases, the respondent propounds for debate an affirmative universal, and not a negative or a particular.76 Aristotle therefore begins with those loci that are useful for refuting an Affirmative Universal; though, in general, the same arguments are available for attack and defence both of the universal and of the particular; for if you can overthrow the particular, you will have overthrown the universal along with it, while if you can defend the universal, this will include the defence of the particular. As the thesis propounded is usually affirmative, the assailant undertakes the negative side or the work of refutation. And this indeed (as Eudemus, the pupil of Aristotle, remarked, after his master77) is the principal function and result of dialectic exercise; which refutes much and proves very little, according to the analogy of the Platonic Dialogues of Search.

Aristotle takes the four heads — Accident, Genus, Proprium, and Definition, in the order here enumerated. The thesis of which the predicate is enunciated as Accident, affirms the least, is easiest to defend, and hardest to upset.78 When we enunciate 285Genus or Proprium, we affirm, not merely that the predicate belongs to the subject (which is all that is affirmed in the case of Accident), but, also something more — that it belongs to the subject in a certain manner and relation. And when we enunciate Definition, we affirm all this and something reaching yet farther — that it declares the whole essence of the definitum, and is convertible therewith. Accordingly, the thesis of Definition, affirming as it does so very much, presents the most points of attack and is by far the hardest to defend.79 Next in point of difficulty, for the respondent, comes the Proprium.

Beginning thus with the thesis enunciating Accident, Aristotle enumerates no less than thirty-seven distinct loci or argumentative points of view bearing upon it. Most of them suggest modes of assailing the thesis; but there are also occasionally intimations to the respondent how he may best defend himself. In this numerous list there are indeed some items repetitions of each other, or at least not easily distinguishable.80 As it would be tedious to enumerate them all, I shall select some of the most marked and illustrative.

1. The respondent has enunciated a certain predicate as belonging in the way of accident, to a given subject. Perhaps it may belong to the subject; yet not as accident, but under some one of the other three Predicables. Perhaps he may have enunciated (either by explicit discrimination, or at least by implication contained in his phraseology) the genus as if it were an accident, — an error not unfrequently committed.81 Thus, if he has said, To be a colour is an accident of white, he has affirmed explicitly the genus as if it were an accident. And he has affirmed the same by implication, if he has said, White (or whiteness) is coloured. For this is a form of words not proper for the affirmation of a genus respecting its species, in which case the genus itself ought to stand as a literal predicate (White is a colour), and not to be replaced by one of its derivatives (White is coloured). Nor can the proposition be intended to be 286taken as affirming either proprium or definition; for in both these the predicate would reciprocate and be co-extensive with the subject, whereas in the present case there are obviously many other subjects of which it may be predicated that they are coloured.82 In saying, White is coloured, the respondent cannot mean to affirm either genus, proprium, or definition; therefore he must mean to affirm accident. The assailant will show that this is erroneous.

2. Suppose the thesis set up by the respondent to be an universal affirmative, or an universal negative. You (the interrogator or assailant) should review the particulars contained under these universals. Review them not at once as separate individuals, but as comprised in subordinate genera and species; beginning from the highest, and descending down to the lowest species which is not farther divisible except into individuals. Thus, if the thesis propounded be, The cognition of opposites is one and the same cognition; you will investigate whether this can be truly predicated respecting all the primary species of Opposita: respecting Relata and Correlata, respecting Contraries, respecting Contradictories, respecting Habitus and Privatio. If, by going thus far, you obtain no result favourable to your purpose,83 you must proceed farther, and subdivide until you come to the lowest species:— Is the cognition of just and unjust one and the same? that of double and half? of sight and blindness? of existence and non-existence? If in all, or in any one, of these cases you can show that the universal thesis does not hold, you will have gained your point of refuting it. On the other hand, if, when you have enumerated many particulars, the thesis is found to hold in all, the respondent is entitled to require you to grant it as an universal proposition, unless you can produce a satisfactory counter-example. If you decline this challenge, you will be considered an unreasonable debater.84

3. You will find it useful to define both the accident predicated in the thesis, and the subject respecting which it is predicated, or at least one of them: you will see then whether these definitions reveal anything false in the affirmation of the thesis. Thus, if the thesis affirms that it is possible to do injustice to a god, you will define what is meant by doing injustice. The 287definition is — hurting intentionally: you can thus refute the thesis by showing that no injustice to a god can possibly be done; for a god cannot be hurt.85 Or let the thesis maintained be, The virtuous man is envious. You define envy, and you find that it is — vexation felt by reason of the manifest success of some meritorious man. Upon this definition it is plain that the virtuous man cannot feel envy: he would be worthless, if he did feel it. Perhaps some of the terms employed in your definition may themselves require definition; if so, you will repeat the process of defining until you come to something plain and clear.86 Such an analysis will often bring out some error at first unperceived in the thesis.

4. It will be advisable, both for assailant and respondent, to discriminate those cases in which the authority of the multitude is conclusive from those in which it is not. Thus, in regard to the meaning of terms and in naming objects, we must speak like the multitude; but, when the question is as to what objects deserve to be denominated so and so, we must not feel bound by the multitude, if there be any special dissentient authority.87 That which produces good health we must call wholesome, as the multitude do; but, in calling this or that substance wholesome, the physician must be our guide.

5. Aristotle gives more than one suggestion as to those cases in which the terms of the thesis have a double or triple sense, yet in which the thesis is propounded either as an universal affirmative or as an universal negative. If the respondent is himself not aware of the double sense of his thesis, while you (the questioner) are aware of it, you will prove the point which you are seeking to establish against him in one or other of the two senses, if you cannot prove it in both. If he is aware of it in the double sense, he will insist that you have chosen the sense which he did not intend.88 This mode of procedure will be available to the respondent as well as to you; but it will be harder to him, since his thesis is universal. For, in order to make good an universal thesis, he must obtain your assent to a preliminary assumption or convention, that, if he can prove it in one sense of the terms, it shall be held proved in both; and, unless the proposition be so plausible that you are disposed to grant him this, he will not succeed in the procedure.89 But you 288on your side, as refuting, do not require any such preliminary convention or acquiescence; for, if you prove the negative in any single case, you succeed in overthrowing the universal affirmative, while, if you prove the affirmative in any single case, you succeed in overthrowing the universal negative.90 Such procedure, however, is to be adopted only when you can find no argument applicable to the equivocal thesis in all its separate meanings; this last sort of argument, wherever it can be found, being always better.91

In cases where the double meaning is manifest, the two meanings must be distinguished by both parties, and the argument conducted accordingly. Where the term has two or more meanings (not equivocal but) related to each other by analogy, we must deal with each of these meanings distinctly and separately.92 If our purpose is to refute, we select any one of them in which the proposition is inadmissible, neglecting the others: if our purpose is to prove, we choose any one in which the proposition is true, neglecting the others.93

6. Observe that a predicate which belongs to the genus does not necessarily belong to any one of its species, but that any predicate which belongs to one of the species does belong also to the genus; on the other hand, that any predicate which can be denied of the genus may be denied also of all its contained species, but that any predicate which can be denied of some one or some portion of the contained species cannot for that reason be denied of the genus. You may thus prove from one species to the genus, and disprove from the genus to each one species; but not vice versâ. Thus, if the respondent grants that there exist cognitions both estimable and worthless, you are warranted in inferring that there exist habits of mind estimable and worthless; for cognition is a species under the genus habit of mind. But if the negative were granted, that there exist no cognitions both estimable and worthless, you could not for that reason infer that there are no habits of mind estimable and worthless. So, if it were granted to you that there are judgments correct and erroneous, you could not for that reason infer 289that there were perceptions of sense correct and erroneous; perceiving by sense being a species under the genus judging. But, if it were granted that there were no judgments correct and erroneous, you might thence infer the like negative about perceptions of sense.94

7. Keep in mind also that if there be any subject of which you can affirm the genus, of that same subject you must be able to affirm one or other of the species contained under the genus. Thus, if science be a predicate applicable, grammar, music, or some other of the special sciences must also be applicable: if any man can be called truly a scientific man, he must be a grammarian, a musician, or some other specialist. Accordingly, if the thesis set up by your respondent be, The soul is moved, you must examine whether any one of the known varieties of motion can be truly predicated of the soul, e.g., increase, destruction, generation, &c. If none of these special predicates is applicable to the soul, neither is the generic predicate applicable to it; and you will thus have refuted the thesis. This locus may serve as a precept for proof as well as for refutation; for, equally, if the soul be moved in any one species of motion, it is moved, and, if the soul be not moved in any species of motion, it is not moved.95

8. Where the thesis itself presents no obvious hold for interrogation, turn over the various definitions that have been proposed of its constituent terms; one or other of these definitions will often afford matter for attack.96 Look also to the antecedents and consequents of the thesis — what must be assumed and what will follow, if the thesis be granted. If you can disprove the consequent of the proposition, you will have disproved the proposition itself. On the other hand, if the antecedent of the proposition be proved, the proposition itself will be proved also.97 Examine also whether the proposition be not true at some times, and false at other times. The thesis, What takes nourishment grows necessarily, is true not always, but only for a certain time: animals take nourishment during all their lives, but grow only during a part of their lives. Or, if a man should say that knowing is remembering, this is incorrect; for we 290remember nothing but events past, whereas we know not only these, but present and future also.98

9. It is a sophistical procedure (so Aristotle terms it) to transfer the debate to some point on which we happen to be well provided with arguments, lying apart from the thesis defended. Such transfer, however, may be sometimes necessary. In other cases it is not really but only apparently necessary; in still other cases it is purely gratuitous, neither really nor apparently necessary. It is really necessary, when the respondent, having denied some proposition perfectly relevant to his thesis, stands to his denial and accepts the debate upon it, the proposition being one on which a good stock of arguments may be found against him; also, when you are endeavouring to disprove the thesis by an induction of negative analogies.99 It is only apparently, and not really, necessary, when the proposition in debate is not perfectly relevant to the thesis, but merely has the semblance of being so. It is neither really nor apparently necessary, when there does not exist even this semblance of relevance, and when some other way is open of bringing bye-confutation to bear on the respondent. You ought to avoid entirely such a procedure in this last class of cases; for it is an abuse of the genuine purpose of Dialectic. If you do resort to it, the respondent should grant your interrogations, but at the same time notify that they are irrelevant to the thesis. Such notification will render his concessions rather troublesome than advantageous for your purpose.100

10. You will recollect that every proposition laid down or granted by the respondent carries with it by implication many other propositions; since every affirmation has necessary consequences, more or fewer. Whoever says that Sokrates is a man, has said also that he is an animal, that he is a living creature, biped, capable of acquiring knowledge. If you can disprove any of these necessary consequences, you will have disproved the thesis itself. You must take care, however, that you fix upon some one of the consequences which is really easier, and not more difficult, to refute than the thesis itself.101

11. Perhaps the thesis set up by the respondent may be of 291such a nature that one or other of two contrary predicates must belong to the subject; e.g., either health or sickness. In that case, if you are provided with arguments bearing on one of the two contraries, the same arguments will also serve indirectly for proof, or for disproof, of the other. Thus, if you show that one of the two contraries does belong to the subject, the same arguments prove that the other does not; vice versâ, if you show that one of them does not belong, it follows that the other does.102

12. You may find it advantageous, in attacking the thesis, to construe the terms in their strict etymological sense, rather than in the sense which common usage gives them.103

13. The predicate may belong to its subject either necessarily, or usually, or by pure hazard. You will take notice in which of these three ways the respondent affirms it, and whether that which he chooses is conformable to the fact. If he affirms it as necessary, when it is really either usual or casual, the thesis will be open to your attacks. If he affirms it without clearly distinguishing in which of the three senses he intends it to be understood, you are at liberty to construe it in that one of the three senses which best suits your argument.104

14. Perhaps the thesis may have predicate and subject exactly synonymous, so that the same thing will be affirmed as an accident of itself. On this ground it will be assailable.105

15. Sometimes the thesis will have more than one proposition contrary to it. If so, you may employ in arguing against it that one among its various contraries which is most convenient for your purpose.106 Perhaps the predicate (accidental) of the thesis may have some contrary: if it has, you will examine whether that contrary belongs to the subject of the thesis; and, should such be the case, you may use it as an argument to refute the thesis itself.107 Or the predicate of the thesis may be such that, if the thesis be granted, it will follow as a necessary consequence that contrary predicates must belong to the same 292subject. Thus, if the thesis be that the Platonic Ideas exist in us, it follows necessarily that they are both in motion and at rest; both perceivable by sense, and cogitable by intellect.108 As these two predicates (those constituting the first pair as well as the second pair) are contrary to each other, and cannot both belong to the same subject, this may be used as an argument against the thesis from which such consequence follows.

16. We know that whatever is the recipient of one of two contraries, is capable also of becoming recipient of the other. If, therefore, the predicate of the thesis has any contrary, you will examine whether the subject of the thesis is capable of receiving such contrary. If not, you have an argument against the thesis. Let the thesis be, The appetitive principle is ignorant. If this be true, that principle must be capable of knowledge.109 Since this last is not generally admitted, you have an argument against the thesis.

17. We recognize four varieties of Opposita: (1) Contradictory; (2) Contrary; (3) Habitus and Privatio; (4) Relata. You will consider how the relation in each of these four varieties bears upon the thesis in debate.

In regard to Contradictories, you are entitled, converting the terms of the thesis, to deny the predicate of the converted proposition respecting the negation of the subject. Thus, if man is an animal, you are entitled to infer, What is not an animal is not a man. You will prove this to be an universal rule by Induction; that is, by citing a multitude of particular cases in which it is indisputably true, without possibility of finding any one case in which it does not apply. If you can prove or disprove the converted obverse of the thesis — What is not an animal is not a man — you will have proved or disproved, the thesis itself, Man is an animal. This locus is available both for assailant and respondent.110

293In regard to Contraries, you will study the thesis, to see whether the contrary of the predicate can be truly affirmed respecting the contrary of the subject, or whether the contrary of the subject can be truly affirmed respecting the contrary of the predicate. This last alternative occurs sometimes, but not often; in general the first alternative is found to be true. You must make good your point here also by Induction, or by repetition of particular examples. This locus will serve either for the purpose of refutation or for that of defence, according to circumstances. If neither of the two alternatives above-mentioned is found correct, this is an argument against the thesis.111

In regard to Habitus and Privatio, the rule is the same as about Contraries; only that the first of the two above alternatives always holds, and the second never occurs.112 If sensible perception can be predicated of vision, insensibility also can be predicated of blindness; otherwise, the thesis fails.

In regard to Relata, the inference holds from the correlate of the subject to the correlate of the predicate. If knowledge is belief, that which is known is believed; if vision is sensible perception, that which is visible is sensibly perceivable. Some say that there are cases in which the above does not hold; e.g., That which is sensibly perceivable is knowable; yet sensible perception is not knowledge. But this objection is not valid; for many persons dispute the first of the two propositions. This locus will be equally available for the purpose of refutation — thus, you may argue — That which is sensibly perceivable is not knowable, because sensible perception is not knowledge.113

18. You will look at the terms of the proposition, also, in regard to their Derivatives, Inflections, &c., and to matters associated with them in the way of production, preservation, &c. This locus serves both for proof and for refutation. What is affirmable of the subject, is affirmable also of its derivatives: what is not affirmable of the derivatives, is not affirmable of the subject itself.114

29419. Arguments may often be drawn, both for proof and for refutation, from matters Similar or Analogous to the subject or predicate of the thesis. Thus, if one and the same cognition comprehends many things, one and the same opinion will also comprehend many things. If to possess vision is to see, then also to possess audition is to hear. If to possess audition is not to hear, then neither is to possess vision to see. The argument may be urged whether the resemblance is real or only generally supposed. Sometimes, however, the inference will not hold from one to many. Thus, if to know is to cogitate, then to know many things should be to cogitate many things. But this last is impossible. A man may know many things, but he cannot cogitate many things; therefore, to know is not to cogitate.115

20. There are various loci for argument, arising from degrees of Comparison — more, less, equally. One is the argument from concomitant variations, which is available both for proof and for disproof. If to do injustice is evil, to do more injustice is more evil. If an increase in degree of the subject implies an increase in degree of the predicate, then the predicate is truly affirmed; if not, not. This may be shown by Induction, or repetition of particular instances.116 Again, suppose the same predicate to be affirmable of two distinct subjects A and B, but to be more probably affirmable of A than of B. Then, if you can show that it does not belong to A, you may argue (à fortiori) that it does not belong to B; or, if you can show that it belongs to B, you may argue (à fortiori) that it belongs also to A. Or, if two distinct predicates be affirmable respecting the same subject but with unequal degrees of probability, then, if you can disprove the more probable of the two, you may argue from thence in disproof of the less probable; and, if you can prove the less probable, you may argue from thence in proof of the more probable. Or, if two distinct predicates be affirmable respecting two distinct subjects but with unequal degrees of probability, then, if you can disprove the more probable you may argue from thence against the less probable; and, if you can prove the less probable, you are furnished with an argument 295in proof of the more probable.117 If the degrees of probability, instead of being unequal, are equal or alike, you may still, in the cases mentioned, argue in like manner from proof or disproof of the one to proof or disproof of the other.118

21. Another locus for argument is, that ex adjuncto. If the subject, prior to adjunction of the attribute, be not white or good, and if adjunction of the attribute makes it white or good, then, you may argue that the adjunct must itself be white or good. And you might argue in like manner, if the subject prior to adjunction were to a certain extent white or good, but became more white or more good after such adjunction.119 But this locus will not be found available for the negative inference or refutation. You cannot argue, because the adjunction does not make the subject white or good, that therefore the adjunct itself is not white or not good.120

22. If the predicate be affirmable of the subject in greater or less degree, it must be affirmable of the subject simply and absolutely. Unless the subject be one that can be called white or good, you can never call it more white or more good. This locus again, however, cannot be employed in the negative, for the purpose of refutation. Because the predicate cannot be affirmed of the subject in greater or less degree, you are not warranted in inferring that it cannot be affirmed of the subject at all. Sokrates cannot be called in greater or less degree a man; but you cannot thence infer that he is not called a man simply.121 If the predicate can be denied of the subject simply and absolutely, it can be denied thereof with every sort of qualification: if it can be affirmed of the subject with qualification, it can also be affirmed thereof simply and absolutely, as a possible predicate.122 This, however, when it comes to be explained, means only that it can be affirmed of some among the particulars called by the name of the subject. Aristotle recognizes that the same predicate may often be affirmed of the subject secundum quid, and denied of the subject simply and absolutely. In some places (as among the Triballi), it is honourable to sacrifice your father; simply and absolutely, it is not honourable. To one who is sick, it is advantageous to undergo medical treatment; speaking simply and absolutely (i.e., to persons generally in the ordinary state of health), it is not advantageous. It is only when you can truly affirm the proposition,296 without adding any qualifying words, that the proposition is true simply and absolutely.123

III.

Such are the chief among the thirty-seven Loci which Aristotle indicates for debating dialectically those theses in which the predication is only of Accident — not of Genus, or Proprium, or Definition. He proceeds (in the Third Book of the Topica) to deal separately with one special branch of such theses, respecting Expetenda and Fugienda: where the question put is, Of two or more distinct subjects, which is the more desirable or the better? The cases supposed are those in which the difference of value between the two subjects compared is not conspicuous and unmistakeable, but where there is a tolerably near approximation of value between them, so as to warrant doubt and debate.124

We must presume that questions of this class occurred very frequently among the dialectical debates of Aristotle’s contemporaries; so that he thinks it necessary to give advice apart for conducting them in the best manner.

1. Of two good subjects compared, that is better and more desirable which is the more lasting; or which is preferred by the wise and good man; or by the professional artist in his own craft; or by right law; or by the multitude, all or most of them. That is absolutely or simply better and more desirable, which is declared to be such by the better cognition; that is better to any given individual, which is declared to be better by his own cognition.125

2. That is more desirable which is included in the genus good, than what is not so included; that which is desirable on its own account and per se, is better than what is desirable only on account of something else and per accidens; the cause of what is good in itself is more desirable than the cause of what is good by accident.126

3. What is good absolutely and simply (i.e., to all and at all times) is better than what is good only for a special occasion or individual; thus, to be in good health is better than being cut for the stone. What is good by nature is better than what is good not by nature; e.g., justice (good by nature), than the 297just individual, whose character must have been acquired.127 What is good, or what is peculiarly appurtenant, to the more elevated of two subjects is better than what is good or peculiar to the less elevated. Good, having its place in the better, prior, and more exalted elements of any subject, is more desirable than good belonging to the derivative, secondary, and less exalted; thus, health, which has its seat in proper admixture and proportion of the fundamental constituents of the body (wet, dry, hot, cold), is better than strength or beauty — strength residing in the bones and muscles, beauty in proper symmetry of the limbs.128 Next, an end is superior to that which is means thereunto; and, in comparing two distinct means, that which is nearer to the end is the better. That which tends to secure the great end of life is superior to that which tends towards any other end; means to happiness is better than means to intelligence; also the possible end, to the impossible. Comparing one subject as means with another subject as end, we must examine whether the second end is more superior to the end produced by the first subject, than the end produced by the first subject is superior to the means or first subject itself. For example, in the two ends, happiness and health, if happiness as an end surpasses health as an end in greater proportion than health surpasses the means of health, then the means producing happiness is better than the end health.129

Again, that which is more beautiful, honourable, and praiseworthy per se, is better than what possesses these same attributes in equal degree but only on account of some other consequence. Thus, friendship is superior to wealth, justice to strength; for no one values wealth except for its consequences, whereas we esteem friendship per se, even though no consequences ensue from it.130

Where the two subjects compared are in themselves so nearly equal that the difference of merit can hardly be discerned, we must look to the antecedents or consequents of each, especially to the consequents; and, according as these exhibit most of 298good or least of evil, we must regulate our estimation of the two subjects to which they respectively belong.131 The larger lot of good things is preferable to the smaller. Sometimes what is not in itself good, if cast into the same lot with other things very good, is preferable to another thing that is in itself good. Thus, what is not per se good, if it goes along with happiness, is preferable even to justice and courage. The same things, when taken along with pleasure or with the absence of pain, are preferable to themselves without pleasure or along with pain.132 Everything is better, at the season when it tells for most, than itself at any other season; thus, intelligence and absence of pain are to be ranked as of more value in old age than in youth; but courage and temperance are more indispensably required, and therefore more to be esteemed, in youth than in old age. What is useful on all or most occasions is more to be esteemed than what is useful only now and then; e.g., justice and moderation, as compared with courage: also that which being possessed by every one, the other would not be required; e.g., justice is better than courage, for, if every one were just, courage would not be required.133

Among two subjects the more desirable is that of which the generation or acquirement is more desirable; that of which the destruction or the loss is more to be deplored; that which is nearer or more like to the Summum Bonum or to that which is better than itself (unless indeed the resemblance be upon the ridiculous side, in the nature of a caricature, as the ape is to man134); that which is the more conspicuous; the more difficult to attain; the more special and peculiar; the more entirely removed from all bad accompaniments; that which we can best share with friends; that which we wish to do to our friends, rather than to ordinary strangers (e.g., doing justice or conferring benefit, than seeming to do so; for towards our friends we prefer doing this in reality, while towards strangers we prefer seeming to do so135); that which we cannot obtain from others, as compared with that which can be hired; that which is unconditionally desirable, as compared with that which is desirable only when we have something else along with it; that of which the absence 299is a ground of just reproach against us and ought to make us ashamed;136 that which does good to the proprietor, or to the best parts of the proprietor (to his mind rather than his body);137 that which is eligible on its own ground, rather than from opinion of others; that which is eligible on both these accounts jointly, than either.138 Acquisitions of supererogation are better than necessaries, and are sometimes more eligible: thus, to live well is better than life simply; philosophizing is better than money-making; but sometimes necessaries are more eligible, as, e.g., to a starving man. Speaking generally, necessaries are more eligible; but the others are better.139

Among many other loci, applicable to this same question of comparative excellence between two different subjects, one more will suffice here. You must distinguish the various ends in relation to which any given subject is declared to be eligible: the advantageous, the beautiful, the agreeable. That which conduces to all the three is more eligible than that which conduces to one or two of them only. If there be two subjects, both of them conducive to the same end among the three, you must examine which of them conduces to it most. Again, that which conduces to the better end (e.g., to virtue rather than to pleasure) is the more eligible. The like comparison may be applied to the Fugienda as well as to the Expetenda. That is most to be avoided which shuts us out most from the desirable acquisitions: e.g., sickness is more to be avoided than ungraceful form; for sickness shuts us out more completely both from virtue and from pleasure.140

The same loci which are available for the question of comparison will also be available in the question of positive eligibility or positive ineligibility.141 Further, it holds for all cases of the kind that you should enunciate the argument in the most general terms that each case admits: in this way it will cover a greater number of particulars. Slight mutations of language will often here strengthen your case: that which is (good) by nature is more (good) than that which is (good) not by nature; that which 300makes the subject to which it is better than that which does not make the subject good.142

The loci just enumerated are Universal, and applicable to the debate of theses propounded in universal terms; but they will also be applicable, if the thesis propounded be a Particular proposition.

If you prove the universal affirmative, you will at the same time prove the particular; if you prove the universal negative, you prove the particular negative also. The universal loci from Opposites, from Conjugates, from Inflections, will be alike applicable to particular propositions. Thus, if we look at the universal locus from Contraries, If all pleasure is good, then all pain is evil, — this will apply also to the particular, If some pleasure is good, then some pain is evil: in the particular as in the universal form the proposition is alike an Endox or conformable to common received opinion. The like may be said about the loci from Habitus and Privatio; also about those from Generation and Destruction;143 again, from More, Less, and Equally — this last, however, with some restriction, for the locus from Less will serve only for proving an affirmative. Thus, if some capacity is a less good than science, while yet some capacity is a good, then, à fortiori, some science is a good. But, if you take the same locus in the negative and say that the capacity is a good, you will not be warranted in saying, for that reason, that no science is a good.144 You may apply this same locus from Less to compare, not merely two subjects in different genera, but also two subjects of different degrees under the same genus. Thus, let the thesis be, Some science or cognition is a good. You will disprove this thesis, if you can show that prudence (φρόνησις) is not a good; for, if prudence, which in common opinion is most confidently held to be a good, be really not so, you may argue that, à fortiori no other science can be so. Again, let the thesis be propounded with the assumption that, if it can be proved true or false in any one case, it shall be accepted as true or false in all universally (for example, that, if the human soul is immortal, all other souls are immortal also; or if not that, then none of the others): evidently, the propounder of such a thesis extends the particular into an universal. 301If he propounds his thesis affirmatively, you must try to prove the negative in some particular case; for this, under the conditions supposed, will be equivalent to proving an universal negative. If, on the other hand, he puts his thesis negatively, you will try to prove some particular affirmative; which (always under the given conditions) will carry the universal affirmative also.145

Suppose the respondent to propound his thesis indefinitely, not carrying the indication either of universal or particular; e.g., Pleasure is good. This can be proved by showing either that all pleasure is good, or that some pleasure is good; while it can be refuted only through the universal negative — by showing that no pleasure is good.146 But, if the thesis be divested of its indefinite character and propounded either as universal or as particular, there will then be two distinct ways of refuting it. If it be farther specialized — e.g., One pleasure only is good — there will be three ways of refuting: you may show either that all pleasures are good; or that no pleasure is good; or that more pleasures than one are good. If the proposition be specialized farther still — e.g., Prudence alone among all the virtues is science, — there are four lines of argument open for refuting it: you may prove either that all virtue is science; or that no virtue is science; or that some other virtue (such as justice) is science; or that prudence is not science.147

In dealing with a particular proposition as thesis, still other loci already indicated for dealing with universal propositions will be available. You will run through the particulars comprised in the subject, distributed into genera and species. When you have produced a number of particulars successively to establish the universal, affirmative or negative, you are warranted in calling on the respondent either to admit the universal, or to produce on his side some adverse particular.148 You will also (as was before recommended) distribute the predicate of the thesis into the various species which it comprehends. If no one of these species be truly affirmable of the subject, then neither can the genus be truly affirmable; so that you will have refuted the thesis, supposing it to be affirmative. If, on the contrary, any one of the species be truly affirmable of the subject, then the genus will also be truly affirmable; so that you will have refuted 302the thesis, supposing it to be negative. Thus, if the thesis propounded be, The soul is a number: you divide number into its two species, odd and even, and prove that the soul is neither odd nor even; wherefore, it is not a number.149

IV.

After this long catalogue of Loci belonging to debate on propositions of Accident, Aristotle proceeds to enumerate those applicable to propositions of Genus and of Proprium. Neither Genus nor Proprium is often made subject of debate as such; but both of them are constituent elements of the debate respecting Definition, which is of frequent occurrence.150 For that reason, both deserve to be studied.

When the thesis propounded affirms that A is genus of B, you will run over all the cognates of B, and see whether there is any one among them respecting which A cannot be affirmed as genus. If there be, this is a good argument against the thesis; for the genus ought to be predicable of all. Next, whether what is really no more than an accident is affirmed as genus, which ought to belong to the essence of the subject. Perhaps (e.g.) white is affirmed in the thesis as being genus of snow; but white cannot be truly so affirmed; for it is not of the essence of snow, but is only a quality or accident.151 Examine whether the predicate A comes under the definition already given of an Accident, — that which may or may not be predicated of the subject; also, whether A and B both fall under the same one out of the ten Categories or Predicaments. If B the subject comes under Essentia, or Quale, or Ad Aliquid, the predicate ought also to belong to Essentia, or Quale, or Ad Aliquid: the species and the genus ought to come under the same Category.152 If this be not the case in a thesis of Genus, the thesis cannot be maintained.

You are aware that the species always partakes of the genus, while the genus never partakes of the species; to partake 303meaning that the species includes the essence or definition of the genus, but the genus never includes the essence or definition of the species. You will examine, therefore, whether in the thesis propounded to you this condition is realized; if not, the thesis may be refuted. Suppose, e.g., that it enunciates some superior genus as including Ens or Unum. If this were true, the genus so assigned would still partake of Ens and Unum; for Ens and Unum maybe predicated of all existences whatever. Therefore what is enunciated in the thesis as a genus, cannot be a real genus.153

Perhaps you may find something respecting which the subject (species) may be truly affirmed, while the predicate (genus) cannot be truly affirmed. If so, the predicate is not a real genus. Thus, the thesis may enunciate Ens or Scibile as being the genus of Opinabile. But this last, the species or subject Opinabile, may be affirmed respecting Non-Ens also; while the predicates Ens or Scibile (given as the pretended genus of Opinabile) cannot be affirmed respecting Non-Ens. You can thus show that Ens or Scibile is not the real genus of Opinabile.154 The pretended species Opinabile (comprising as it does both Ens and Non-Ens) stretches farther than the pretended genus Ens or Scibile: whereas every real genus ought to stretch farther than any one or any portion of its constituent species.155 The thesis may thus be overthrown, if there be any one species which stretches even equally far or is co-extensive with the pretended genus.156

It is a general truth that the same species cannot belong to two distinct genera, unless one of the two be subordinate to the other, or unless both of them be comprehended under some common higher genus. You will examine, therefore, whether there is any other genus, besides the predicate of the thesis, to which the subject of the thesis can be referred. If there be some other genus, not under either of the two conditions above indicated, the predicate enunciated by the thesis cannot be the real genus of the subject. Thus, if the thesis declares justice to be science (or to belong to the genus science), you may remark that there is another distinct genus (virtue) to which justice also belongs. In this particular case, however, it would be replied that science and virtue can both be referred to one and the same higher genus, viz., habit and disposition. Therefore304 the thesis, Justice is science, will not be truly open to objection on this ground.157

Again, if the predicate of the thesis be the true genus of the subject, all the higher genera in which the predicate is contained must also be predicated in Quid (as the predicate itself is) respecting the subject. This you must show by an induction of particular instances, no counter-instance being producible.158 If the thesis enunciated does not conform to this condition, you will have a good argument against it. You will also run over the sub-species that are comprehended in the subject of the thesis, considered as a genus; and you will examine whether the predicate of the thesis (together with all its superior genera) is predicable essentially or in Quid of all these sub-species. If you can find any one among these sub-species, of which it is not essentially predicable, the predicate of the thesis is not the true genus of the subject;159 the like also, if the definitions of those genera are not predicable of the subject or its sub-species.160

Perhaps the thesis may enunciate as a genus what is really nothing more than a differentia. It may also enunciate the differentia either as a part of the genus or as a part of the species; or it may enunciate the genus either as a part of the differentia or as a part of the species. All these are attackable. The differentia is not a genus, nor does it respond to the question Quid est, but to the question Quale quid est. It is always either more extensive than the species, or co-extensive therewith.161 If none of the differentiæ belonging to a genus can be predicated of a species, neither can the genus itself be predicated thereof. Thus, neither odd nor even can be predicated of the soul; accordingly, neither can the genus 305(number) be predicated of the soul.162 If the species be prius naturâ, so that when it disappears the enunciated genus disappears along with it, this cannot be the real genus; nor, if the enunciated genus or differentia can be supposed to disappear and yet the species does not disappear along with them.163 If the species partakes of (includes in its essence) something contrary to the enunciated genus, this last cannot be the real genus; nor, if the species includes something which cannot possibly belong to what is in that genus. Thus, if the soul partakes of (or includes in its essence) life, and if no number can possibly live, the soul cannot be a species of number.164

Again, the generic term and the specific term ought to be univocal in signification. You must examine (according to the tests indicated in the First Book of the Topica) whether it be taken equivocally in the thesis. If it be so, you have a ground of attack, and also if it be taken metaphorically; for every genus ought to be enunciated in the proper sense of the term, and no metaphor can be allowed to pass as a genus.165 Note farther that every true genus has more than one distinct species. You will, therefore, examine whether any other species, besides the subject of the thesis, can be suggested as belonging to the predicate of the thesis. If none, that predicate cannot be the true genus of the subject.166

Several loci are furnished by Contraries, either to the species or the genus. If there be something contrary to the species, but nothing contrary to the genus, then that which is contrary to the species ought to be included under the same genus as the species itself; but, if there be something contrary to the species, and also something contrary to the genus, then that which is contrary to the species ought to be included in that which is contrary to the genus. Each of these doctrines you will have to make good by induction of particular cases.167 If that which is contrary to the species be a genus itself (e.g., bonum) and not included in any superior genus, then the like will be true respecting the species itself: it will not be included in any genus; and the predicate of the thesis will not be a true genus. Bonum and malum are not included in any common superior genus; each is a genus per se.168 Or suppose that the subject (species) of 306the thesis, and the predicate (genus) of the thesis, have both of them contraries; but that in the one there is an intermediate between the two contraries, and in the other, not. This shows that the predicate cannot be the true genus of the species; for, wherever there is an intermediate between the two contraries of the species, there also is an intermediate between the two contraries of the genus; and vice versâ.169 If there be an intermediate between the two contraries of the species, and also an intermediate between the two contraries of the genus, you will examine whether both intermediates are of like nature, designated by analogous terms. If it be not so (if, e.g., the one intermediate is designated by a positive term, and the other only by a negative term), you will have ground for contending against the thesis, that the predicate enunciated therein is not the true genus of the subject. At any rate, this is a probable (ἔνδοξον) dialectical argument — to insist upon analogy between the two intermediates; though there are some particular cases in which the doctrine does not hold.170

Again, suppose different conditions: that there is no contrary to the genus, but that there is a contrary to the species. You will examine whether not merely the contrary of the species, but also the intermediate between its two contraries, is included in the same genus; for, if the two contraries are included therein, the intermediate ought also to be included. This is a line of argument probable (i.e., conformable to general presumption, and recommendable in a dialectical debate), though there are not wanting examples adverse to it: thus, excess and defect are included in the same genus evil, but the moderate or measured (τὸ μέτριον) is not in the genus evil, but in the genus good.171 We must remark, moreover, that though it be a probable dialectical argument, that, wherever the genus has a contrary, the species will also have a contrary, yet there are cases adverse to this principle. Thus, sickness in general has for its contrary health in general; but particular species of sickness (such as fever, ophthalmia, gout, &c.) have no contrary.172

Such will be your way of procedure, if the thesis propounded be Affirmative, and if you have to make out a negative against it. But if, on the contrary, the thesis be Negative, so that you have to make out an affirmative against it, you have then three 307lines of procedure open. 1. The genus may have no contrary, while the species has a contrary: in that case, you may perhaps be able to show that the contrary of the species (subject) is included in the predicate of the thesis (genus); if so, then the species also will be included therein. 2. Or, if you can show that the intermediate between the species and its contrary is included in the predicate (genus), then that same genus will also include the species and its contrary; for, wherever the intermediate is, there also are the two extremes between which it is intermediate. 3. Lastly, if the genus has a contrary as well as the species, you may be able to show that the contrary of the species is included in the contrary of the genus; assuming which to be the case, then the species itself will be included in the genus.173 These are the three modes of procedure, if your task is to make out the negative.

If the genus enunciated by the thesis be a true one, all the Derivatives and Collaterals of the predicate will be fit and suitable for those of the subject. Thus, if justice be a sort of science, justly will be scientifically, and the just man will be a scientific man. This locus is useful to be kept in mind, whether you have to make out an affirmative or a negative.174 You may reason in the same way about the Analoga of the predicate and the subject; about the productive and destructive causes of each; the manifestations present, past, and future, of each, &c.175

When the opposite of the species (subject) is Privative, the thesis will be open to attack in two ways. 1. If the privative opposite be contained in the predicate, the subject itself will not be contained therein; for it is a general truth that a subject and its privative opposite are never both of them contained in the same lowest genus: thus, if vision is sensible perception, blindness is not sensible perception. 2. If both the species and the genus have privative opposites, then if the privative opposite of the species be contained in the privative opposite of the genus, the species itself will also be contained in the genus; if not, not. Thus, if blindness be an inability of sensible perception, vision will be a sensible perception. This last locus will be available, whether you are making out an affirmative or a negative.176

If the predicate of the thesis be a true genus, you may convert the thesis simply, having substituted for the predicate the denial of its Contradictory; if not, not. Vice versâ, if the new proposition308 so formed be true, the predicate of the thesis will be a true genus; if not, not. Thus, if good be the true genus of pleasurable, nothing that is not good will be pleasurable. This locus also will serve both for making out an affirmative and for making out a negative.177

If the subject (species) of the thesis be a Relative, you will examine whether the predicate (genus) be relative also; if not, it will not be the true genus of the subject. The converse of this rule, however, will not hold; and indeed the rule itself is not absolutely universal.178 You may also argue that, if the correlate of the genus be not the same as the correlate of the species, the genus cannot be truly predicated of that species: thus, half is the correlate of double, but half is not the proper correlate of multiple; therefore, multiple is not the true genus of double. But your argument may here be met by contradictory instances; thus, cognition has reference to the cognitum, but habitus and dispositio (the genera to which cognitio belongs) do not refer to cognitum but to anima.179 You may also examine whether the correlate, when applied to the genus, is put in the same case (e.g., genitive, dative, &c.) as when it is applied to the species: if it be put into a different case, this affords presumption that the genus is not a true genus; though here again instances may be produced showing that your presumption will not hold universally. Farther, you will observe whether the correlates thus similarly inflected reciprocate like the species and genus; if not, this will furnish you with the same adverse presumption.180

Again, examine whether the correlate of the genus is genus to the correlate of the species; if it be not so, you may argue that the genus is not truly predicated. Thus, if the thesis affirms that perceptio is the genus of cognitio, it will follow that percipibile is the genus of cognoscibile. Now this cannot be maintained; for there are some cognoscibilia which are not perceivable, e.g., some cogitabilia (intelligibilia, νοητά). Since therefore percipibile is not the true genus of cognoscibile, neither can perceptio be the true genus of cognitio.181

309Suppose the thesis predicates of memory that it is — a continuance of cognition. This will be open to attack, if the predicate be affirmed as the genus (or even as the accident) of the subject. For every continuance must be in that which continues. But memory is of necessity in the soul; it cannot therefore be in cognition.182 There is another ground on which the thesis will be assailable, if it defines memory to be — a habit or acquirement retentive of belief. This will not hold, because it confounds habit or disposition with act; which last is the true description of memory. The opposite error will be committed if the respondent defines perceptivity to be a — movement through or by means of the body. Here perceptivity, which is a habit or disposition, is ranked under movement, which is the act exercising the same, i.e., perceptivity in actual exercise.183 Or, the mistake may be made of ranking some habit or disposition under the power consequent on the possession thereof, as if this power were the superior genus: thus the respondent may define gentleness to be a continence of anger; courage, a continence of fears; justice, a continence of appetite of lucre. But the genus here assigned is not a good one: for a man who feels no anger is called gentle; a man who feels no fear is called courageous; whereas the continent man is he who feels anger or fear, but controls them. Such controlling power is a natural consequence of gentleness and courage, insomuch that, if the gentle man happened to feel anger, or the courageous man to feel fear, each would control these impulses; but it is no part of the essence thereof, and therefore cannot be the genus under which they fall.184 A like mistake is made if pain be predicated as the genus of anger, or supposition as the genus of belief. The angry man doubtless feels pain, but his pain precedes his anger in time, and is the antecedent cause thereof; now the genus can never precede its species in time. So also a man may have the same supposition sometimes with belief, sometimes without it; accordingly,310 supposition cannot be the genus of belief any more than the same animal can be sometimes a man, sometimes a brute.185 And indeed the same negative conclusion would follow, even if we granted that every supposition was always attended with belief. For, in that case, supposition and belief would be co-extensive terms; but the generic term must always be more extensive than its specific.186

You will farther examine whether the predicate of the thesis be of a nature to inhere in the same substance as the subject. If it be not, it cannot be truly predicated thereof, either as genus or even as accident. White (species) and colour (genus) are of a nature to inhere or belong to the same substance. But, if the thesis declares that shame is a species of fear, or that anger is a species of pain, you may impugn it on the ground that shame belongs to the reasoning element in man, fear to the courageous or energetic element; and that pain belongs to the appetitive element, anger to the courageous. This proves that fear can neither be the genus nor the accident of shame; that pain can neither be the genus nor the accident of anger.187

Suppose the thesis declares that animal is a species under the genus visibile or percepibile. You may oppose it by pointing out that animal is only visibile secundum quid, or partially; that is, only so far as regards body, not as regards mind. But the species always partakes of its genus wholly, not partially or secundum quid; thus, man is not partially animal, but wholly or essentially animal. If what is predicated as the genus be not thus essentially partaken, it cannot be a true genus; hence neither visibile nor percepibile is a true genus of animal.188

Sometimes what is predicated as the genus is, when compared to its species, only as a part to the whole; which is never the case with a true genus. Some refer animal to the genus living body; but body is only part of the whole animal, and therefore cannot be the true genus thereof.189 Sometimes a species which 311is blameworthy and hateful, or a species which is praiseworthy and eligible, may be referred to the power or capacity from which it springs, as genus; thus, the thief, a blameworthy and hateful character, may be referred to the predicate — capable of stealing another man’s property. But this, though true as a predicate, is not the true genus; for the honest man is also capable of so acting, but he is distinguished from the thief by not acting so, nor having the disposition so to act. All power and capacity is eligible; if the above were the true genus of thief, it would be a case in which power and capacity is blameworthy and hateful. Neither, on the other hand, can any thing in its own nature praiseworthy and eligible, be referred to power and capacity as its genus; for all power and capacity is praiseworthy and eligible not in itself or its own nature, but by reason of something else, namely, its realizable consequences.190

Again, you may detect in the thesis sometimes the mistake of putting under one genus a species which properly comes under two genera conjointly, not subalternate one to the other; sometimes, the mistake of predicating the genus as a differentia, or the differentia as a genus.191 Sometimes, also, the subject in which the attribute or affection resides is predicated as if it were the genus of such affection; or, è converso, the attribute or affection is predicated as the genus of the subject wherein it resides; e.g., when breath or wind, which is really a movement of air, is affirmed to be air put in motion, and thus constituted as a species under the genus air; or when snow is declared to be water congelated; or mud, to be earth mixed with moisture.192 In none of these cases is the predicate a true genus; for it cannot be always affirmed of the subject.

Or perhaps the predicate affirmed as genus may be no genus at all; for nothing can be a genus unless there are species contained under it; e.g., if the thesis declare white to be a genus, this may be impugned, because white objects do not differ in specie from each other. Or a mere universal predicate (such as Ens or Unum) may be put forward as a genus or differentia; 312or a simple concomitant attribute, or an equivocal term, may be so put forward.193

Perhaps it may happen that the subject (species) and the predicate (genus) of the thesis may each have a contrary term; and that in each pair of contrary terms one may be better, the other worse. If, in that case, the better species be referred to the worse genus, or vice versâ, this will render the thesis assailable. Or perhaps the species may be fit to be referred equally to both the contrary genera; in which case, if the thesis should refer it to the worse of the two, that will be a ground of objection. Thus, if the soul be referred to the genus mobile, you are at liberty to object that it is equally referable to the genus stabile: and that, as the latter is the better of the two, it ought to be referred to the better in preference to the worse.194

There is a locus of More and Less, which may be made available in various ways. Thus, if the genus predicated admits of being graduated as more or less, while the species of which it is predicated does not admit of such graduation, you may question the applicability of the genus to the species.195 You may raise the question also, if there be any thing else which looks equally like the true genus, or more like it than the genus predicated by the thesis. This will happen often, when the essence of the species includes several distinct elements; e.g., in the essence of anger, there is included both pain (an emotional element), and the supposition or belief of being undervalued (an intellectual element); hence, if the thesis ranks anger under the genus pain, you may object that it equally belongs to the genus supposition196 This locus is useful for raising a negative question, but will serve little for establishing an affirmative. Towards the affirmative, you will find advantage in examining the subject (species) respecting which the thesis predicates a given genus; for, if it can be shown that this supposed species is no real species but a genus, the genus predicated thereof will be à fortiori a genus.197

Some think (says Aristotle)198 that Differentia as well as Genus is predicated essentially respecting the Species. Accordingly, Genus must be discriminated from Differentia. For such discrimination313 the following characteristics are pointed out:— 1. Genus has greater extent in predication than Differentia. 2. In replying to the enquiry, Quid est? it is more suitable and significant to declare the Genus than the Differentia. 3. Differentia declares a quality of Genus, and therefore presupposes Genus as already known; but Genus does not in like manner presuppose Differentia. If you wish to show that belief is the genus to which cognition belongs, you must examine whether the cognoscens believes quâ cognoscens. If he does so, your point is made out.199

Wherever a predicate is universally true of its subject, while the proposition is not true if simply converted (i.e., wherever the predicate is of larger extension than the subject), there is difficulty in distinguishing it from a genus. Accordingly, when you are respondent, maintaining the affirmative side, you will use such predicate as if it were a genus; but, when you are assailant, you will not allow the respondent to do so. You may quote against him the instance of Non-Ens; which is predicable of every thing generated, but which is not a genus, since it has no species under it.200

V.

Aristotle passes, in the Fifth book of the Topica, to those debates in which the thesis set up declares the predicate as Proprium of the subject.

A Proprium may belong to its subject either per se and semper, or relatively to something else and occasionally or sometimes. It is a proprium per se of man to be an animal by nature tractable. It is a relative proprium of the soul in regard to the body, to exercise command; of the body in regard to the soul, to obey command. It is a proprium semper of a god, to be immortal; it is an occasional proprium (i.e., sometimes) of this or that man, to be walking in the market-place.201 When the proprium is set out relatively to something else, the debate must involve two questions, and may involve four. Thus, if the thesis affirms that it is a proprium of man relatively to horse (discriminating man from horse) to be by nature two-footed, you 314may (as opponent) either deny that man is two-footed, or affirm that horse is two-footed; or you may go farther and affirm that man is by nature four-footed, or deny that horse is by nature four-footed. If you can succeed in showing any one of these four, you will have refuted the thesis.202

The Proprium per se discriminates its subject from everything else, and is universally true thereof; the relative Proprium discriminates its subject only from some other assignable subject. The relative Proprium may be either constant and universally true, or true with exceptions — true and applicable in the ordinary course of things: it may be tested through those Loci which have been enumerated as applicable to the Accident. The Proprium per se, and the constant Proprium, have certain Loci of their own, which we shall now indicate. These are the most logical (sensu Aristotelico) or suitable for Dialectic; furnishing the most ample matter for debates.203

Aristotle distinguishes (1) those cases in which the alleged proprium is a true proprium, but is incorrectly or informally set out in the thesis, from those (2) in which it is untruly predicated, or is no proprium at all.

To set out a proprium well, that which is predicated ought to be clearer and better known than the subject of which it is predicated, since the purpose of predicating the proprium is to communicate knowledge.204 If it be more obscure or less known, you may impugn the thesis as bad in form, or badly set out. Thus, if the thesis declare, as a proprium of fire, that fire is of all things the most like to the soul, this is not well set out, because the essence of the soul is not so well known as the essence of fire. Moreover, the fact that the predicate belongs to the subject, ought to be better known even than the subject itself; for whoever is ignorant that A belongs to B at all, cannot possibly know that A is the proprium of B.205 Thus, if the thesis declare, as proprium of fire, that it is the first or most universal subject in which it is the nature of soul to be found, the predicate is here doubly unknowable: first, the hearer does not know that the soul is found in fire at all; next, he does not 315know that fire is the first subject in which soul is found. On the other hand, the respondent will repel your attack if he can show that his proprium is more knowable in both the two above-mentioned ways. If, for example, he declares as thesis, To have sensible perception is the proprium of an animal, here the proprium is both well known in itself, and well known as belonging to the given subject. Accordingly, it is well set out, as far as this condition is concerned.206

A second condition of its being well set out is, that it shall contain neither equivocal term nor equivocal or amphibolical proposition. Thus, if the thesis declares, To perceive is the proprium of an animal, it is equivocal; for it may mean either to have sensible perception, or to exercise sensible perception actually. You may apply the test to such a thesis, by syllogizing from one or both of these equivocal meanings. The respondent will make good his defence, if he shows that there is no such equivocation: as, for example, if the thesis be, It is a proprium of fire to be the body most easily moved into the upper region; where there is no equivocation, either of term or proposition.207 Sometimes the equivocation may be, not in the name of the proprium itself, but in the name of the subject to which it is applied. Where this last is not unum et simplex but equivocal, the thesis must specify which among the several senses is intended; and, if that be neglected, the manner of setting out is incorrect.208

Another form of the like mistake is, where the same term is repeated both in the predicate and in the subject; which is often done, both as to Proprium and as to Definition, though it is a cause of obscurity, as well as a tiresome repetition.209 The repetition may be made in two ways: either directly, by the same term occurring twice; or indirectly, when the second term given is such that it cannot be defined without repeating the first. An example of direct repetition is, Fire is a body the rarest among bodies (for proprium of fire). An example of indirect repetition is, Earth is a substance which tends most of all bodies downwards to the lowest region (as proprium of earth); for, when the respondent is required to define bodies, he must define them — such and such substances.210 An example free from objection on this ground is, Man is an animal capable of receiving cognition (as proprium of man).

316Another mode of bad or incorrect setting out is, when the term predicated as proprium belongs not only to the subject, but also to all other subjects. Such a proposition is useless; for it furnishes no means of discriminating the subject from anything; whereas discrimination is one express purpose of the Proprium as well as of the Definition.211 Again, another mode is, when the thesis declares several propria belonging to the same subject, without announcing that they are several. As the definer ought not to introduce into his definition any words beyond what are required for declaring the essence of the subject, so neither should the person who sets out a proprium add any words beyond those requisite for constituting the proprium. Thus, if the thesis enunciates, as proprium of fire, that it is the thinnest and lightest body, here are two propria instead of one. Contrast with this another proprium, free from the objection just pointed out — Moist is that which may assume every variety of figure.212

A farther mistake is, when the predicate declaring the proprium includes either the subject itself or some species comprehended under the subject; for example, when we are told, as a proprium of animal, that animal is a substance of which man is a species. We have already seen that the proprium ought to be better known than its subject; but man is even less known (posterior in respect to cognition) than animal, because it is a species under the genus animal.213

Again, our canon — That the Proprium should be better known than its subject, or should make the subject better known — will be violated in another way, if the proprium enunciated be something opposite to the subject, or in any other way simul naturâ as compared with the subject; and still more, if it be posterius naturâ as compared with the subject. Thus, if a man enunciates, as proprium of good, that good is that which is most opposite to evil, his proprium will not be well or correctly set out.214

Perhaps, again, the thesis may enunciate as proprium what is not constantly appurtenant to the subject, but is sometimes absent therefrom; or, intending to enunciate an occasional proprium, it may omit to specify the qualifying epithet occasional. 317In either case the proprium is not well set out, and a ground is furnished for censure, which ought always to be avoided.215

Moreover, the proprium will not be well set out, if it be such as does not necessarily belong to the subject, but is only shown by the evidence of sense to belong thereunto. In this case, when the subject is out of the reach of sensible perception, no one knows whether the supposed proprium still continues as its attribute. Thus, suppose the thesis to enunciate as a proprium of the sun, that it is the brightest star borne in movement above the earth: the fact that it is so borne in movement above the earth is one that we know by sensible perception only; accordingly, after the sun sets and we cease to see it, we cannot be sure that it continues to be borne in movement. If a proprium knowable as such by sense be chosen, it ought to be one which is also knowable independently, as belonging to the subject by necessity. Thus, if a man enunciates, as proprium of superficies, that superficies is what first becomes coloured or first receives colour, this is a proprium well set out. For we know clearly that it must always belong to a superficies; though we may also obtain the additional evidence of sense, by looking at some perceivable body.216

Perhaps too the thesis may enunciate the Definition as if it were a Proprium; which is another ground for objecting that the proprium is not well set out. Thus, the thesis may enunciate, as proprium of man, that man is a land animal walking on two feet. Here what is given as proprium is the essence of man, which never ought to be affirmed in the proprium. To set out the proprium well, the predicate ought to reciprocate and to be co-extensive with the subject, but it ought not to affirm the essence thereof. A good specimen of proprium well set out is the following, Man is an animal by nature gentle; for here the predicate is co-extensive with the subject, yet does not declare the essence of the subject.217

Lastly, the proprium, to be well set out, though it does not declare the essence of the subject, yet ought to begin by presupposing the generic portion of the essence, and to attach itself 318thereunto as a constant adjunct or concomitant. Thus, suppose the thesis to enunciate, as proprium, Animal is that which has a soul; this will not be well set out, for the predicate is not superadded or attached to the declared generic essence of animal. But, if the thesis enunciates, as proprium of man, Man is an animal capable of acquiring cognition, — this will be a proprium well set out, so far as the present objection is concerned. For here the predicate declares first the generic essence of the subject, and then superinduces the peculiar adjunct thereupon.218

Thus far Aristotle has pointed out certain conditions to be attended to in determining whether a Proprium is well set out or described, without determining whether it be really a Propium or not. It may perhaps be truly predicated of the subject, and may even admit of a better description which would show it to be a proprium of the subject; but the description actually set out is defective, and the assailant is entitled to impeach it on that ground. He now proceeds to a larger discussion: What are the conditions for determining whether the supposed Proprium be really a Proprium at all, in respect to the subject of which it is predicated? Assuming that the description of it is not open to impeachment on any of the grounds above enumerated, are there not other real grounds of objection, disproving its title to the character of Proprium?219

1. Suppose your respondent to set up A as a proprium of B: you will examine first whether A can be truly predicated of B at all; next, if it can so be, whether it is truly predicable of B quâ B, or of every thing that comes under B quâ B. Thus, if he contends that not to be deceived by reason is a proprium of scientific men, you will be able to show that this does not hold in geometry, since geometricians are deceived by pseudographemes 319or scientific paralogisms. Or, should the respondent deny that A is a proprium of B, you will succeed in refuting him, if you can prove that A is truly predicable of every B and quâ B. Thus, it is a proprium of man to be an animal capable of acquiring knowledge; because that attribute is truly predicable of every man quâ man.220

2. Again, suppose your respondent affirms a given proprium A of B: you will examine whether A can be truly predicated of every thing called B, and whether B can be truly predicated of every thing called A; if not, the alleged proprium will not hold. Thus the affirmation, A god is an animal participant of knowledge, is a true affirmation; but it would not be true to say, A god is a man: wherefore, to be participant of knowledge is not proprium of man; and, if this be the proprium which the respondent undertakes to maintain, you will be able to refute him. On the other hand, if what he undertakes is the negation of a proprium (A is not a proprium of B), you will establish the affirmative against him by showing that of every thing respecting which A can be truly affirmed B can be affirmed also, and vice versâ. You will thus show that A is a true proprium of B.221

3. Again, the respondent may perhaps affirm the subject itself as a proprium of something inherent in the subject. You may refute this by showing that, if it were so, the same thing would be a proprium of several things differing from each other in species. On the other hand, the respondent may perhaps deny that something inherent in the subject is a proprium: you may then refute him by showing that it is truly predicable of the subject only, and not truly predicable of any thing else.222

4. The respondent may perhaps affirm as a proprium something contained in the essence of the subject: if so, you will refute him by showing this. On the other hand, if he denies something to be a proprium, you will refute him by showing that, though it is not contained in the essence of the subject, it is nevertheless predicable co-extensively therewith.223

5. The respondent may affirm as a proprium that which is not a necessary concomitant of the subject, but may either precede or follow it. Or, on the other hand, he may deny something to be a proprium which you can show to be a constant and 320necessary concomitant of the subject, without being included either in its definition or differentia. In each case you will have a ground for refuting him.224

6. The respondent may affirm as a proprium of the subject what he has already denied of the same subject under some other name; or he may deny of it what he has already affirmed of it under some other name. You will have grounds for refuting him.225

7. If there be two subjects (e.g., man and horse) the same with each other in species, the respondent may affirm respecting one of them a proprium which is not the same in species with the proprium of the other. Thus, it is not a constant proprium of horse to stand still spontaneously; accordingly neither is it a constant proprium of man to move spontaneously; these two propria being the same in species, and belonging both to man and to horse quatenus animal.226 If, therefore, the respondent affirms the one while he denies the other, you have an argument in refutation. On the other hand, he may propound as thesis the denial of the one proprium, while he affirms or admits the other. Here too you will be able to make good the counter-affirmation against his denial, on the ground of that which he admits. Thus, if it be proprium of man to be a walking-biped, it must also be proprium of bird to be a flying-biped. The two pairs, man and bird, walking and flying, are the same in species with each other, since both pairs are subordinates under the same genus: man and bird are species, flying and walking are differentiæ, under the same genus animal. This locus, however, is not universally applicable; for perhaps one of the two predicates may not be of exclusive application to the subject, but may belong to other subjects also. Thus walking-biped designates only one variety — man; but walking-quadruped designates several — horse, ass, dog, &c. Walking-quadruped therefore is not a proprium of horse.227

8. There is some difficulty in discussing the proprium, when 321the respondent is assailed by a sophistical dialectician who avails himself of the equivocal application of Idem and Diversum: contending that Subject with an Accident becomes a different subject — e.g., homo albus, a subject different from homo (so that, when a proprium has been shown to belong to homo, it has not been shown that the same proprium belongs to homo albus); and that the Abstract is a different subject from the Concrete — e.g. cognition, from the cognizing man (so that what has been shown as proprium of cognition has not been shown as proprium of the cognizing man). If the respondent shall himself set up these negatives, leaving to you the task of establishing the proprium against him, you will meet him by saying that homo is not a subject absolutely different and distinct from homo albus, but that there is only a notional distinction, the same subject having here two names each with a distinct connotation: homo has its own connotation; homo albus has also its own connotation, embodying in one total that which each of the terms connotes. And, when the Sophist remarks that what is a proprium of scientia cannot be predicated also as a proprium of homo sciens, you will reply that it may be so predicated, only with a slight change of inflection. For you need not scruple to employ sophistical refutation against those who debate with you in a sophistical way.228

9. The respondent may perhaps intend to affirm as proprium something which by nature belongs to the subject; but he may err in his mode of stating it, and may predicate it as always belonging to the subject. Thus, he may predicate biped as a proprium always belonging to man. Under this mode of expression, you will be able to show that he is wrong; for there are some men who have not two feet. On the other hand, if the respondent denies biped to be a proprium of man, relying upon the statement that it is not actually true of every individual,322 you will be able to show against him that it is so in the correct phraseology of belonging to man by nature.229

10. That which is affirmed as a proprium may belong to its subject either primarily and immediately, or in a secondary way — relatively to some prior denomination of the same subject. In such cases it is difficult to set out the proprium in terms thoroughly unobjectionable. Thus, the superficies of a body is what is first coloured: when we speak of corpus album, this is by reason of its white superficies. Album is a proprium true both of body and of superficies; but the explanation usually given of Proprium will not hold here — that, wherever the predicate can be affirmed, the subject can be affirmed also. Album is proprium of superficies; and album can be truly affirmed as also proprium of body; but superficies cannot be truly affirmed of body.230

11. The respondent who is affirming a Proprium may sometimes err by not clearly distinguishing in what mode, and in respect to what precise subject, he intends to affirm it. There are ten different modes, in one or other of which he always proposes to affirm it:—231

a. As belonging to the subject by nature. E.g., Biped is by nature a proprium of man.

b. As belonging to the subject simply — in some way or other. E.g., To have four fingers, belongs to Koriskus or some other individual man.

c. As belonging to the species. E.g., It belongs to fire to be the most subtle of all bodies.

d. As belonging absolutely (ἁπλῶς, καθάπερ ζῴου τὸ ζῆν) — in virtue of the essence of the subject — per se.232

323e. As belonging to the subject by reason of some primary intervening aspect or attribute thereof. E.g., Prudence is a proprium of the soul, looked at quatenus reasonable or intellectual.

f. As belonging to that primary attribute or special aspect, logically distinguished and named separately from the subject. E.g., Prudence is a proprium of the logistikon or rationale.

g. As belonging to the subject viewed as possessing or holding in possession. E.g., The scientific man possesses that acquired mental habit which renders him incapable of having his convictions farther altered by discussion.

h. As belonging to some possession held by a possessing person. E.g., Science is unalterable by discussion; where science, a possession of the scientific man, is assigned as subject of the proprium, unalterable by discussion.

i. As belonging to a subject which is partaken or held in participation by another subject lying behind. E.g., Sensible perception is a proprium of the genus animal which genus is partaken or held in participation by this individual man, that individual horse, &c.; whence it may be predicated not only of animal but also of man, as thus participant.

k. As belonging to the ultimate subject partaking. E.g., To live is a proprium of this particular man or horse, participant in the genus animal, in the way just indicated.

Now each of these varieties of the Proprium is liable to its own mode of erroneous setting out or description. Thus the corresponding errors will be:—233

a. Not to add the qualifying words by nature.

b. Not to state the proprium as simply belonging, when it does only belong to the subject now, and may presently cease to belong.

c. Not to state the proprium as belonging to the species. If he omits these words, he may be told that it belongs to one variety alone among the species (e.g., should it be a superlative) and not to others: perhaps it may 324 belong to some conspicuously, and to others faintly. Or perhaps, if he does add the express words — to the species, he may err, inasmuch as there exists no real species properly so called.

e. f. Not to distinguish whether he means to affirm it of B by reason of A, or of A directly: he will lay himself open to the objection that his proprium, and the subject term of which he declares it to be a proprium, are not co-extensive in predication.

g. h. Not to distinguish whether he intends as subject the person possessing, or the possession. If he leaves this undetermined, the objector may attack him on one ground or the other.

i. k. Not to distinguish whether he means as subject the partaker, or the genus which is partaken. Here too the objector will have ground for attack either from one side or from the other.

In case the respondent should enunciate his proprium in any one of the above defective ways, you will thus know where to find objections against him. But, if you undertake yourself to enunciate a proprium, you will avoid laying yourself open to the objections, by discriminating under which of these heads you intend to affirm it.234

12. Again, the respondent may perhaps affirm as proprium a predicate really identical with the subject, though under a different name. Thus, he may declare to τὸ πρέπον to be a proprium τοῦ καλοῦ: you may then refute him by showing that πρέπον is identical with καλόν. If he is on the negative side, denying A to be a proprium of B on the ground that A is identical with B, you will make out the affirmative against him by showing that A is not identical with B, but only co-extensive and reciprocating therewith. Thus, you may show that animated substance is not identical with animal, but a proprium of animal.235

13. Where the subject is homœomeric, the respondent may declare as proprium of the whole what cannot be truly affirmed as proprium of a part separately; or he may declare as proprium of a part separately what cannot be truly declared as proprium of the whole. In either case, you have a plausible argument for refuting him; but your refutation will not be always conclusive, 325because there are various cases in which what is true of each homœomeric part is not true of the whole; and vice versâ. If your position in the debate is affirmative, you will select as illustration some case in which what is by nature true of the whole is also true of each separate part: e.g., The earth as a whole, and each of its parts, tend by nature downwards. This is a proprium of the earth.236

14. Respecting Opposita, there are different loci for different varieties.

a. Contraria. — Suppose the respondent to affirm A as proprium of B: you will examine whether the contrary of A is proprium of the contrary of B. If it be not, then neither is A proprium of B. Thus, if best is not a proprium of justice, neither can worst be a proprium of injustice. If the respondent is on the negative side, you may prove the affirmative against him by showing that the contrary of the alleged proprium is a proprium of the contrary of the alleged subject.237

b. Relata. — Suppose the respondent to affirm a relatum A as proprium of a relatum B, you may refute him by showing that the correlate of A is not proprium of the correlate of B. Suppose him to deny the same, you will refute him by proving the affirmative between correlate and correlate.238

c. Habitus et Privatio. — Suppose the respondent to affirm an attribute of the habitus B, as proprium thereof: you may refute him by showing that the corresponding attribute of the privatio correlating with habitus B, is not proprium of that privatio. Suppose him to take the negative side, you will refute him by proving the affirmative of this latter proposition.239

15. Respecting Contradictory Propositions (affirmation and negation of the same), more than one mode of dealing may be stated. Wherever the affirmation is a proprium of the subject, the negation cannot also be a proprium thereof; and vice versâ. If the affirmative predicate be not a proprium of the affirmative subject, neither can the negative predicate be proprium of the negative subject; and vice versâ. If the affirmative predicate be proprium of the affirmative subject, the negative predicate will also be proprium of the negative subject. The same predicate cannot be proprium both of the affirmative subject and of the negative subject.240

16. Respecting two or more Contra-Specific Terms under the 326same genus and exhausting the whole genus:— Suppose A and B contra-specific terms used as subjects; C and D contra-specific terms used as predicates. If C be not a proprium of A, neither will D be a proprium of B; thus, if perceivable (αἰσθητόν) is not a proprium of any other species (except gods) included under the genus animal, neither will intelligible (νοητόν) be proprium of a god. Again, if C be a proprium of A, D also will be a proprium of B. Thus, if it be a proprium of prudence to be by its own nature the excellence of the rational or calculating soul (λογιστικοῦ), we must also affirm as proprium of temperance that it is the excellence of the appetitive soul (ἐπιθυμητικοῦ).241

17. Respecting Cases or Inflections, either of the subject B, or the predicate A:— If the case or inflection of the predicate be not a proprium of the corresponding case or inflection of the subject, neither will the predicate be proprium of the subject. If the case or inflection of the predicate be a proprium of the corresponding case or inflection of the subject, then the predicate itself will also be proprium of the subject. Pulchré is not proprium of justé; therefore, pulchrum is not proprium of justum.

This locus will be found available in combination with the preceding locus bearing on Opposita. Not only opposita themselves, but also the cases and inflections of opposita, may be adduced as arguments, following the rules above laid down.242

18. Analogous cases or propositions:— If the respondent affirms A as proprium of B, you have an argument against him by showing that something analogous to A is not proprium of a subject analogous to B. Thus, the builder, in relation to house-making, is analogous to the physician, in relation to health-making; now health-making is not the proprium of the physician, and therefore neither is house-making the proprium of the builder. If the respondent has advanced a negative, you will apply this same locus in the affirmative against him: e.g., as it is the proprium of the gymnast to impart a good habit of body, so it is the proprium of the physician to impart health.243

19. Esse, and Generari or Fieri:— If A considered as Ens is not the proprium of B considered as Ens, then neither will A considered as Fiens be the proprium of B considered as Fiens. Vice 327versâ, on the affirmative side: if the former of these two be the fact, you may argue that the latter is the fact also.244

20. Comparison with the Idea:— If the respondent sets up A as proprium of B, you will turn your mind to the Idea of B, and note whether A is proprium of this Idea, in the same sense and under the same aspect as it is affirmed to be proprium of B. If it be not so, you will have an argument in refutation of the respondent. Thus, if he maintains that it is a proprium of man to be at rest, you will argue that this cannot be so, because to be at rest is not the proprium of the Self-man (αὐτοάνθρωπος) quatenus man, but quatenus Idea. Vice versâ, you will have an affirmative argument, if you can show that it is the proprium of the Idea. Thus, since it is a proprium of the self-animal quatenus animal to be composed of soul and body, you may infer that to be composed of soul and body is really a proprium of animal.245

21. Locus from More and Less:— Suppose the respondent to affirm A as proprium of B: you will have an argument against him, if you can show that what is more A is not proprium of that which is more B. Thus, if to be more coloured is not proprium of that which is more body, neither is to be less coloured proprium of that which is less body; nor is to be coloured proprium of body simply. Vice versâ, if you can show that what is more A is proprium of what is more B, you will have an affirmative argument to establish that A is proprium of B. Thus, to perceive more is proprium of that which is more living. Hence, to perceive simply is proprium of that which is living simply; also, to perceive most, least, or less, is proprium of that which is most, least, or less living, respectively.246

If you can show that A simply is not proprium of B simply, you have an argument to establish that what is more or less A is not proprium of that which is more or less B. If, on the other land, you show the affirmative of the first, this will be an argument sustaining the affirmative of the last.247 Perhaps you can show that what is more A is not proprium of what is more B: this will be an argument to show that A is not proprium of B. Thus, to perceive is more proprium of animal than to know is proprium of man; but to perceive is not proprium of animal; therefore, to know is not proprium of man. Or again, if you can show that what is less A is proprium of what is less B, this will form an argument to show that A is proprium of B. Thus, natural mansuetude is less proprium of man than life is proprium328 of animal; but natural mansuetude is proprium of man: therefore life is proprium of animal.248 Farther, if you can show that A is more a proprium of C than it is a proprium of B, yet nevertheless that it is not a proprium of C you may thence argue that A is not a proprium of B. Thus, to be coloured is more a proprium of superficies than it is a proprium of body; yet it is not a proprium of superficies; therefore, it is not a proprium of body. This last variety of the locus of More and Less (Aristotle remarks) affords no corresponding affirmative plea;249 for the same predicate cannot be a proprium of many subjects. If A be really a proprium of superficies, it cannot be also proprium of body. Lastly, you may perhaps be able to show that C is more a proprium of B than A is a proprium of B; yet, if C is not a proprium of B, you will infer negatively that neither is A proprium of B. Thus, to be perceivable is more proprium of animal, than to be divisible is proprium of animal; yet to be perceivable is not proprium of animal, and, therefore, neither is to be divisible proprium of animal. You may invert this argument for the affirmative, if you can show that C is less a proprium of B than A is a proprium of B, yet still that C is a proprium of B; hence you will infer, à fortiori, that A is a proprium thereof. E.g., If to perceive is less a proprium of animal than to live is a proprium thereof, yet to perceive is a proprium of animal; then, to live is so likewise.250

22. Locus from Equal Relation:— Arguments both negative and affirmative may in like manner be obtained by comparing different things which are (not more or less propria, but) alike or equally propria of some other subject. If A is as much a proprium of B as C is proprium of D, while yet A is not a proprium of B, you may hence infer that C is not a proprium of D. If, under this hypothesis, A is a proprium of B, you may infer affirmatively that C is a proprium of D.251 Or, if A and C be, alike and equally, propria of the same subject B, then, if you show that A is not proprium thereof, you will infer negatively that C is not so; if you show that A is proprium of B, you will infer affirmatively that C is so likewise. Or, thirdly, if A be, alike and equally, a proprium of B and of E, then, if you can show that A is not a proprium of E, you may infer negatively that it is not a proprium of B. Here, however, the counter-inference affirmatively is not allowable; for the same proprium cannot belong as proprium to two distinct subjects, as was stated before.252

32923. Locus from Potentiality:— No potentiality whatever can belong to Non-Ens. Accordingly, if A, the proprium affirmed of a subject B, is a potentiality, this must imply some real Ens in which it inheres, and which is correlate to the subject. But, if in the specification of the proprium no allusion is made to such correlate, you will attack it as a bad proprium — as a potentiality inhering in Non-Ens or nothing. E.g., if the case be, It is a proprium of air to be respirable, you will refute this by pointing out that this is true only when there exist animals in whom the potentiality of breathing resides; that no mention is made by the respondent of this correlate or of any other correlate; in other words, that, so far as the specification is concerned, the correlate is passed over as Non-Ens or a non-entity. Therefore the proprium is not a good proprium.253 Again, suppose the affirmation to be, It is a proprium of Ens to be capable of doing or suffering something; this will be defensible because it is only when the subject is Ens, that it is declared to have such proprium.254

24. Locus from the Superlative:— Suppose the affirmation to be, It is a proprium of fire to be the lightest of all bodies: this you may refute by showing that, if fire ceased to exist, there would still be some other body the lightest of all bodies. Therefore the proprium may still be predicated of something else, when its alleged subject has ceased to exist. The proprium and its subject are not reciprocating and co-extensive; therefore it is not a true proprium.255

VI.

We now enter on the Sixth Book, containing the Loci bearing on Definition. In debates respecting Definition, there are five points on any of which the attack and defence may turn:—256

3301. That which the definer enunciates as a definition may not be true at all, even as a predicate of the definiend or subject to be defined; or at least not true of everything that bears the name of the subject.

2. The definiend may have been included in a genus, but not in that genus to which it rightly and specially belongs.

3. The definition given may not be specially appropriate to the definiend (i.e., it may include, not only that but, other matters besides).

4. The definition, though unobjectionable on any of the above three grounds, may nevertheless not declare the Essence of the definiend.

5. Lastly, the definition may be good in substance, but badly expressed or set out.

As to the first of these five heads, the Loci bearing thereupon have already been enumerated in the Third Book, on Accident: in accidental predications the question raised is always about the truth or falsehood of the predication.257 As to the second and third of the five heads, these have been dealt with in the Fourth and Fifth Books, enumerating the Loci on Genus and Proprium.258

There remain the fourth and fifth heads, on which we are about to enter: (1) Whether the definition is well expressed or set out (the fifth head); (2) Whether it has any right to be called a definition at all, i.e., whether it declares the Essence of the subject (the fourth).259 The fifth is taken first, because to do a thing well is always more difficult than to do it simply, and is therefore likely to afford greater opening for argumentative attack.

The definition, while unobjectionable in substance, may be badly set out in two ways. First, it may be indistinct in terms — not plain nor clear. Next, it may be redundant: the terms may include more than is required for the definition. Under each of these defects of expression several loci may be indicated.260

1. Indistinctness may arise from the employment of equivocal terms in the definition. Or it may arise from the term to be defined being itself equivocal; while the definer, taking no notice of such equivocation, has tried to comprehend all its senses under one and the same definition. You may attack him either by denying that the definition as given covers all the different meanings of the definiend; or you may yourself distinguish (which the definer has omitted to do) these different meanings,331 and show that none of them or few of them are covered by the definition.261

2. Indistinctness may arise from defining by means of a metaphor; but Aristotle treats you as a caviller if you impugn this metaphor as though it were proprio sensu.262 He declares it to be wrong, but he seems to think that you ought to object to it at once as a metaphor, without troubling yourself to prove it inappropriate.

3. Indistinctness will arise if the terms of the definition are rare or far-fetched or founded upon some fact very little known.263 Definitions given by Plato are cited to illustrate this.

4. Indistinctness arises from the employment of a poetical image, which is even worse than a professed metaphor: as where law is defined to be — a measure or image of things by nature just.264

5. The definition is indistinct, if it does not, while making known the definiend, make clear at the same time its contrary.265

6. The definition is also indistinct if it does not, when enunciated, make known what the definiend is, without requiring that the definiend itself shall be expressly enunciated. The definition by itself ought to suggest at once the name of the definiend. Otherwise, the definer is no better than those archaic painters, who, when painting a dog or a horse, were compelled to write the name alongside in order that the animal might be recognized.266

Such are the Loci regarding Indistinctness in the setting out of the definition. The second defect is Redundancy.

1. Redundancy will arise if the terms of the definition include either all things absolutely, or all things contained in the same genus as the definiend; since the definition ought to consist of a generic term to discriminate the definiend from all 332extra-generic things, and a differential term to discriminate it from other things within the same genus. A definition of the kind mentioned will be useless through redundancy.267 It will also be open to the like objection, if it includes what is merely a proprium of the definiend, over and above the essential attributes; or, indeed, if it includes any thing else except what is required for clearly bringing out the definiend.268 It will be still worse, if it comprises any attribute not belonging to all individuals of the species; for then it will not even be a proprium or a reciprocating predication.269

2. Repetition is another fault sometimes committed. The same attribute may be predicated twice over. Or a particular and narrow attribute may be subjoined, in addition to a more general and comprehensive attribute in which it has already been included.270

So much for the faults which belong to the manner of expressing the definition tendered. Next, as bearing on the matter and substance of the definition, the following loci are distinguishable.

1. The first of these loci is, if the matter of the definition is not prius and notius as compared with the definiend. It is one of the canons of Definition, the purpose of which is to impart knowledge of the definiend, to introduce nothing except what is prior by nature and better known than the latter. The essence of each definiend — the being what it is — is one and only one. If a definition be given, other than that by means of what is prius and notius, it would follow that the same definiend might have two distinct essences; which is impossible. Accordingly, any proposition tendered as a definition but enunciating what is not prior by nature and better known than the definiend sins against this canon, and is to be held as no true definition at all.271

The locus here indicated by this general feature is one, but it includes a number of varieties.272 More known, or less known, it should first be observed, has two distinct meanings: either more or less known absolutely (by nature); or more or less known to us. Absolutely, or by nature, the point is better known than 333the line; the line, than the superficies; the superficies, than the solid; the prius, than the posterius. But to us the reverse is true. The solid, as object of sensible perception, is earlier known and more known than the superficies; the superficies, than the line; the line, than the point; the posterius, than the prius. To us means to the bulk of mankind: absolutely or by nature refers to the instructed, superior, teaching and expository, intellects.273 There may be some cases in which the notius nobis coincides and is identical with the notius naturâ;274 but, as a rule, the two are distinct, and the one is the inverse of the other. A genuine and perfect definition is one which enunciates the essence of the Species through Genus and Differentiæ, which are both of them absolutely prior and more knowable than the Species, since, if they be supposed non-existent, the Species is nowhere to be found. No man can know the Species without knowing its Genus and Differentiæ; but you may know the Genus and Differentiæ without knowing the Species; hence the Species is more unknowable than they are.275 This is the true scientific definition; but there are persons incapable of acquiring knowledge by means of it. To these persons, an imperfect explanation or quasi-definition must be given, by means of matters knowable to them.276 Those, however, who regard such imperfect explanations as true definitions, must be reminded that, upon that hypothesis, we should be compelled to admit many distinct definitions of the same definiend. For individuals differ from each other in respect to what is more knowable: what is more so to one man is not more so to another. Indeed the same man differs from himself on this point at different periods: to the early and untrained mind objects of sensible perception are the most knowable; but, when a man has been improved by training and instruction, the case is reversed, and the objects of intellect become the most familiar to his mind.277 334To define properly, therefore, we must enunciate, not the notiora nobis but, the notiora naturâ or simpliciter; understanding by this last phrase, not what is more knowable to all actual men but, what is more knowable to men of well-trained and well-constituted intellect; just as, when we speak of the wholesome, we mean what is wholesome to the well-constituted body.278 These conditions of Definition you must thoroughly master, and apply to each debate as the occasion may require. Your task in refuting an alleged definition will be the easiest in those cases where it conforms to neither of the above conditions; that is, when it enunciates neither what is notius naturâ nor what is notius nobis.279

The canon being, That what is posterius must be defined by its prius, — the definer may sin against this in defining the prius by its posterius; e.g., if he defines the stationary and the determinate by means of the moveable and the variable.280 Also, when his definition is neither prius, nor posterius, but of equal position with the definiend, he is at fault. This may happen (1) when he defines by an Opposite (for, according to some, the science of Opposites is one and the same, and it is impossible that either one of a pair can be absolutely more knowable than 335the other; though it is true that no relative can be understood or explained without the knowledge of its correlative, e.g., double and half); or (2) when he includes the definiend itself in his definition, either under its proper name or any other name;281 or (3) when he defines by means of a contra-specific to the definiend — by something of equal specific rank or position, which is therefore simul naturâ therewith (e.g., Odd is that which is greater than even by unity); or (4) when he defines by something specifically subordinate (e.g., An even number is that which may be bisected, where bisected means divisible by two, itself one among the even numbers282).

2. The second locus (after that bearing on the Prius et Notius) of argument for impugning a definition is, where it does not enunciate the genus in which the definiend is really included. The mention of the genus, as enunciating the fundamental essence of the definiend, ought to stand first in the definition. If your opponent defines body — that which has three dimensions, or man — that which knows how to count, you attack him by asking, What is it that has three dimensions? What is it that knows how to count? No genus has been assigned.283

3. A third locus is, where the definiend is a complex whole having reference to several distinct facts or phenomena, while the definition indicates only one of them. Thus, if grammar be defined — the knowing how to write from dictation, you will object that it is just as much — the knowing how to read. The definition is incomplete unless it includes both.284

4. A fourth locus is, where the definiend admits both of a better and a worse construction, and where the definition enunciates only the worse. You may impugn it, on the ground that every cognition and every power must be understood as tending to its best results.285

6. A fifth locus is, where the definiend is enunciated as ranking, not in the lowest and nearest species to which it belongs but, in some higher and more distinct genus. Here the real essence will not be declared, and the definition will thus be incomplete; unless indeed it includes, along with the highest genus, the superadded mention of all the differentiæ descending down to the lowest species. It will then be complete, because it will include, in circumlocutory phrase, all that would be declared by enunciating the specific name.286

3366. Assuming the genus to be truly declared in the definition you will examine whether the differentiæ enunciated are differentiæ at all? whether they really belong to the definiend? what is it which they serve to contrast with and exclude, — since, if there be nothing such, they cannot be truly differentiæ? whether the differential term and its counter-differential apply to and cover the whole genus? whether, granting the differentia to be real, it be such, when taken along with the genus, as to constitute a true species, and whether its counter-differentia be such also? This is a locus furnishing many possibilities of impugning the definition.287

7. Perhaps the definition may enunciate a differentia which is merely negative; e.g., A line is length without breadth. If you are debating with a respondent who holds the (Platonic) doctrine of Ideas, and who considers each Idea or genus to be something numerically one, distinct from all its participants, you will find here a locus for attacking them.288 He asserts the existence of a Self-long or generical long, a Self-animal or generic animal, each numerically one. Now, upon this hypothesis, since of all long you may predicate either in the affirmative or the negative (i.e., either it is broad or it is not broad), so this alternative may be predicated of the Self-long or generical long; and thus the genus will coincide with, or fall under the definition of, one among its own species. Or, if this be denied, it will follow that the generic long must be both broad and not broad; which is a contradiction still more inadmissible. Accordingly, against one who holds the doctrine of Ideas, declaring the genus to be unum numero, the negative differentia will furnish grounds for attack; but not against any other respondent.289 For there are various cases in which the negative must be employed as a part of the differentia: e.g., in privative terms, blind is one whose nature it is to see but who does not see. And, even when the differentia enunciated is affirmative, it may have for its condivident member only a negative term, e.g., length having-breadth has for its condivident member only the negative, length not-having-breadth.290

8. Perhaps the definition may enunciate as a differentia what is really a subordinate species; or what is really the genus itself under another name; or what is not Quale, but Quid; or what 337belongs to the definiend as an accident only. Each of these is a locus for arguments against the definition.291

9. Perhaps also, in the definition given, the differentia or the species may be found predicable of the entire genus; or the genus may be found predicable of the differentia itself, and not of objects under it; or the species (sometimes even one of its sub-species) may be found predicable of the differentia; or perhaps the differentia may not be a prius as regards the species (which it ought to be, while it is a posterius as regards the genus). Arguments against the definition may be drawn from any one of these loci.292

10. Recollect that the same differentia cannot belong to two distinct genera neither of which comprehends the other, unless both are comprehended under some higher genus. Examine whether this is observed in the definition tendered to you.293

11. No genuine differentia can be derived either from the Category Ubi or from the Category Passio; for neither of them furnishes characteristics essential to the subject. All Passio when intensified to a certain degree destroys the essence of the subject and removes it from its own appropriate species; but the differentia is inseparable from its subject; accordingly, nothing by virtue of which the subject is called ἀλλοῖον can be a true differentia. If the definition sins against this rule, it will be open to question.294

12. If the subject be relative, its true differentia ought to be relative also; thus, science or cognition is a relatum, and accordingly its three differentiæ — theoretical, practical, constructive — are all relata also.295 The definition must conform to this; and it must also, in cases where the relative subject has more than one correlate, declare that correlate which is the ordinary and natural one, not any other which is rare and realized only on occasion.296 You must watch to see whether this condition is observed; and also whether the correlative enunciated in the definition is the one strictly proximate. Thus, if the definition given of prudence be, It is an excellence of man or an excellence of the soul, this will not be a good definition. It ought to be — an excellence of the rational department of the soul; for it is 338through and by reason of this department that both man and soul are denominated prudent.297

13. When the definiend is given as an affection or lasting condition of some subject, you must examine whether it really resides or can reside (as by nature it ought to do) in the subject to which it is referred in the definition. If it cannot, the definition is untenable; and this mistake is sometimes made, the producing conditions of a phenomenon being confounded with the phenomenon itself, or vice versâ.298 Thus, some persons have defined sleep — incapacity of sensible perception; doubt — equality of contrary reasonings; pain — breach of continuity violently made in parts of the organism which naturally grow together. Now sleep does not reside in perception, nor doubt in reasonings. Sleep is that which produces or occasions incapacity of sensible perception; doubt is a state of mind produced by equality of contrary reasonings.299 This will be a locus for arguing against the definition.

14. Another locus is, when the definiend has direct bearing and reference to something different from what is enunciated in the definition. Thus, if the respondent defines justice — a power tending to make equal distribution, you may remark hereupon, that the just man is he who is deliberately resolved to make equal distribution, not he who has the power to do so. If this definition were allowed, the justest man would be he who has the greatest power of so distributing.300

15. Again, the definition will be assailable, if the definiend admits graduation of More or Less, while that which is enunciated in the definition does not admit it, or vice versâ; also, if both of them admit graduation, but the variations of the two are not corresponding and concomitant. The defining phrase ought to be identical in signification with the term defined.301 If both of them agree in reference to some common correlate, but one is to this in the relation of more while the other is in the relation of less, the definition is faulty.302

16. Again, you will be able to object, if the definition enunciate references to two distinct correlates, severally or alternately: e.g., 339The beautiful is that which affords pleasure either through the eye or through the ear; Ens is that which is capable either of suffering or acting. You may show that, according to this definition, beautiful and not beautiful, or that Ens and Non-Ens, will coincide and be predicable of the same subjects.303

17. When the definition is tendered, you ought to examine and define its own terms, which, of course, profess to enunciate genus and differentia of the definiend.304 You will see whether the definitions of those defining terms are in any way inapplicable to the definiend.

18. If the definiend be a Relatum, the definition ought to enunciate its true correlate, or the true correlate of the genus to which it belongs. You must examine whether this is done, and whether the correlate enunciated be an ultimate end, as it ought to be (i.e. not merely a means towards something ulterior). If the correlate enunciated is a generation or a process, this will afford you an argument against the definition; for all generation or process is a means towards some ulterior end.305

19. The definition ought not to omit any of the differentiæ of the definiend; if any be omitted, the real essence is not declared. Here then is a defect in the definition, which it is your business always to assail on its defective side.306 Thus, if the definiend be a relatum corresponding, not to some correlate absolutely but, to some correlate specially quantified or qualified, the definition ought to enunciate such quantification or qualification; if it does not, it is open to attack.

20. Suppose that the definiend is one of the appetites, relative to an appetitum as correlate, a mode of the good or agreeable. You will take notice whether the definition given thereof enunciates the correlate as only an apparent mode of good: if it does not, you have a locus for attacking it. But if it does, and if the definer be one who believes in the Platonic Ideas, you may attack him by showing that his definition will not square with that doctrine. For the definition as so given will not suit for the 340ideal or generic appetite — the Self-appetite; which correlates with the ideal or generic good — the Self-good. In this no distinction is admissible of real and apparent: a Self-apparent-good is an absurdity.307

21. Again, suppose that the definiend is a habit or disposition. You will examine how far the definition fits as applied to the individual person who has the habit; and how far it fits when taken in comparison with subjects contrary or congeneric. Every such definition, if good, implies in a certain way the definition of the contrary: he who defines cognition furnishes by implication the definition of ignorance.308

22. Or suppose the definiend to be a generic relatum, and the definition to enunciate its generic correlate. You must call to mind the specific terms comprehended under these two generic terms, and observe whether they fit on to each other respectively. If they do not, the definition is faulty.309

23. You will farther examine whether the Opposite of the definition will serve as definition to the Opposite of the definiend, as the definition of half is opposite to the definition of double; thus, if double is that which exceeds equality, half is that which is exceeded by equality. The like is true of Contraries: if the profitable be that which is productive of good, the hurtful will be that which is productive of evil or destructive of good. If, on trying the contraries, you find that this will not hold, the definition originally given will be found unsatisfactory.310 In defining the privative contrary of any term, a man cannot avoid enunciating in the definition the term of which it is the privative: but he is not allowed to define the term itself by means of its privative. To define equality — that which is contrary to inequality, is improper. You will require him at once to define inequality; and his definition must be — the privation of equality. 341Substitute this definition of the term inequality, in place of that term itself, in the above-named definition of equality: and the last definition will then run as follows: Equality is that which is contrary to the privation of equality. Here the definiend is enunciated as a part of the definition of itself; a proof that the original definition — Equality is the contrary of inequality — is itself wrong.311

24. When the definiend is a Privative Term, the definition given ought to enunciate that which it is, and that of which it is the privation; also that subject in which it resides naturally and in the first instance. In defining ignorance, the definition must enunciate not privation only, but privation of knowledge; nor will this be sufficient unless it be added that the privation of knowledge is in the rational department of the soul (ἐν τῷ λογιστικῷ). Privation of knowledge in the soul or in the man, will not suffice; because neither of these subjects is that in which the attribute resides in the first instance: the rational department of the soul must be named by itself, as being the primary subject of the attribute. If the definition be wanting in any of these conditions, you will have an argument for impeaching it.312

25. A term that is privative in form may sometimes be used in the sense of mere negation, not in that of privation. If this term be defined generally by privation, the definition will not include the merely negative sense, and will therefore be impeachable. The only general explanation attainable is that by pure negation, which is common both to the negative and the privative. Thus, if the respondent defines ignorance — privation of knowledge, such privation can be predicated only of subjects whose nature it is to have knowledge or who might be expected to have it: such privation cannot be predicated of infants, or of inanimate objects like stones. To include these, ignorance must be explained as the mere negation or non-existence of knowledge; the definition thereof by privation is inadequate.313

26. If you are debating with one who holds the Platonic doctrine of Ideas, you will note whether any definition that he may give fits not only the definiend itself but also the Idea of the definiend. Thus, Plato in defining animal introduces mortality342 as a part of his definition;314 but mortality cannot be predicated of the Idea or generic animal — the Self-animal; therefore, you will have an argument against his definition. In like manner, if any active or passive attribute is brought into his definition, you will object that this cannot apply to the Ideas; which are avowedly impassive and unchangeable.315

27. Another locus for counter-argument is, where the definiend is Equivocal or Analogous, while one and the same definition is made to apply to all its distinct meanings. Such a definition, pretending to fit all, will in reality fit none; nothing but an univocal term can come under one and the same definition. It is wrong to attempt to define an equivocal term.316 When its equivocation is not obvious, the respondent will put it forward confidently as univocal; while you as assailant will expose the equivocation. Sometimes, indeed, a respondent may pretend that an univocal word is equivocal, or that an equivocal word is univocal, in the course of the debate. To obviate such misconception, you will do well to come to an agreement with him prior to the debate, or to determine by special antecedent reasonings what terms are univocal or equivocal; for at that early stage, when he does not foresee the consequence of your questions, he is more likely to concede what will facilitate your attack. In the absence of such preliminary agreement, if the respondent, when you have shown that his bad definition will 343not apply universally, resorts to the pretence that the definiend, though really univocal, is equivocal, you will press him with the true definition of the part not included under his definition, and you will show that this true definition suits also for the remaining parts of the definiend. You will thus confute him by showing that, upon his original hypothesis, it must follow that there are two distinct definitions for the same definiend — the bad one which he has given, and the true one which you have constrained him to admit.317 Perhaps, however, the term which he has undertaken to define may be really equivocal, and therefore indefinable; nevertheless, when you have shown the insufficiency of his definition, he may refuse to admit that the term is equivocal, but will deny a portion of its real meaning. You will then remind him that, as to the meaning of names, we must recognize tradition and custom without presuming to disturb it; but that, when we combine these names in our own discourse, we must beware of those equivocations which mislead the multitude.318

28. If the definiend, of which a definition is tendered to you, is a compound, you may subtract from this definition the definition of one of the parts of the definiend, and then examine whether the remainder will suit as a definition of the remaining part of the definiend. If the remainder should not suit, this will show that the entire definition tendered is not tenable. Thus, if the definiend be a finite straight line, and if the definition tendered be, It is the boundary of a finite plane, of which (boundary) the middle covers or stands in the way of the extremities; you may subtract from this definition the definition of a finite line, viz., the boundary of a plane surface having boundaries, and the remainder of the definition ought then to suit for the remainder of the definiend. Now the remainder of the definiend is — straight; and the remainder of the definition is — that of which the middle covers or stands in the way of the extremities. But these two will not suit; for a line may be straight, yet infinite, in which case it will have neither middle nor extremities. Accordingly, since the remainder of the definition344 will not suit for the remainder of the definiend, this will serve as an argument that the entire definition tendered is not a good one.319

If the definiend be a compound, and if the definition contain no greater number of words than the definiend, the definition must be faulty; it will be nothing better than a substitution of words. Still more faulty will it be, if it substitutes rare and strange words in place of others which are known and familiar; or if it introduces a new word which signifies something different from that which it replaces.320

The definiend, being compound, will contain both a generic and a differential term. In general, the generic term will be the better known of the two; yet sometimes the other is the better known. Whichever of the two is the better known, the definer ought to choose that, if all that he aims at is a mere substitution of one name in place of another. But, if he aims at something more or at the substitution of an explanatory proposition in place of a name (without which there can be no true definition), he ought then to choose the differentia in preference to the genus; for the definition is produced for the purpose of imparting knowledge, and the differentia, being usually less known than the genus, stands most in need of extraneous help to cognition.321 When the definition of the differentia has thus been tendered, you will examine whether it will be equally suitable for any other definiend also. If it be, you have an argument against the goodness of the definition. For example, the definition of odd number tendered to you may be — number having a middle. Here, since number is common both to the definiend and to the definition, having-a-middle is evidently put forward as the equivalent of odd. But this cannot stand as equivalent to odd; since various other subjects which are not odd (such, for example, as a body or a line), nevertheless have a middle. Since, then, we see that having-a-middle would be suitable in defining definiends which are not odd, it cannot be admitted, without some qualifying adjunct, as a good definition of odd. The adjunct annexed must declare in what sense middle is intended, since it is an equivocal phrase.322

29. If the definiend be a something really existent, the definition given of it ought not to be a proposition declaring an incompatible combination, such as neither does nor can exist. Some, for example, define white — colour mingled with fire; which is 345incompatible, since that which is incorporeal (colour) cannot be mingled with a body (fire).323

30. Again, suppose the definiend to be a Relatum: the correlate thereof must of course be declared in the definition. Care, however, must be taken that it shall be declared, not in vague generality but, distinctly and with proper specialization; otherwise, the definition will be incorrect either entirely or partially. Thus, if the respondent defines medicine — the science of the really existent, he is incorrect either wholly or partially. The relatum ought to reciprocate or to be co-extensive with its correlate.324 When the correlate, however, is properly specialized in the definition, it may be declared under several different descriptions; for the same real thing may be at once ens, album, bonum. None of these descriptions will be incorrect. Yet, if the correlate is thus described in the definition of a relatum, the definition cannot be considered good or sufficient. For it applies to more things besides the definiend; and a good definition ought to reciprocate or to be co-extensive with its definiend.325

31. Another mistake in defining is committed, when a man defines, not the subject purely and simply but, the subject in a high measure of excellence. Sometimes the rhetor (e.g.) is defined — one who can perceive and produce without omission all that there is plausible in any cause; the thief is defined — one who takes away secretly what belongs to another. But these are the definitions, not of a rhetor and a thief generally but, of a skilful rhetor and skilful thief. The thief is one who is bent on taking away secretly, not one who does take away secretly.326

32. Again, another error consists in defining what is desirable in itself and on its own account, as if it were desirable as a means towards some other end — as productive or preservative thereof. For example, if a man defines justice — that which is preservative of the laws; or wisdom — that which is productive of happiness, he presents them as if they were desirable, not for themselves but, with reference to something different from themselves. This is a mistake; and it is not less a mistake, though very possibly the same subject may be desirable both for 346itself and for the sake of something else. For the definition ought to enunciate what is best in the definiend; and the best of everything resides most in its essence, not in what it is relatively to something else. It is better to be desirable per se, than alterius causâ.327

33. Perhaps the definition tendered may be a complex proposition, enunciating two terms either jointly or severally, in one or other of three combinations. Either the definiend is A and B; or it is that which springs out of A and B; or it is A with B.328 In each of these three cases you may find arguments for impugning the definition.

a. Thus, take the first of the three. Suppose the respondent to define justice by saying, It is temperance and courage. You may urge against him, that two men, one of whom is temperate without being courageous, while the other is courageous without being temperate, will be just together, though neither of them separately is just; nay, that each of them separately (the one being temperate and cowardly, the other courageous and intemperate), will be both just and unjust; since, if justice is temperance and courage, injustice will be intemperance and cowardice.329 The definer is open to the farther objection that he treats enumeration of parts as identical with the whole; as if he defined a house — bricks and mortar, forgetting the peculiar mode of putting them together. Bricks and mortar may exist, and yet there may be no house.330

b. Next, suppose the definition to declare, that the definiend is that which springs from A and B — is a result or compound of A and B. You will then examine whether A and B are such as to yield any result; for some couples (as a line and a number) yield no result. Or, perhaps, the definiend may by its own nature inhere in some first subject, while A and B do not inhere in any one first subject, but one in the other; in which case the definition is assailable.331 Or, even granting that it is the nature of A and B to inhere in the same first subject, you may find that that first subject is not the same as the one in which the definiend inheres. Now the whole cannot thus inhere in one, and the parts in another: you will here have a good objection. 347Or, perhaps, it may appear that, if the whole be destroyed, the parts will be destroyed also; which ought not to be, but the reverse; for, when the parts are destroyed, the whole must necessarily vanish. Or, perhaps, the definiend may be good or bad, while the parts of the definition (A and B) are neither one nor the other. (Yet this last is not a conclusive objection; for it will sometimes happen in compound medicines that each of the ingredients is good, while they are bad if given in conjunction.)332 Or, perhaps, the whole may bear the same name as one of its parts: this, also, will render the definition impeachable. Still more will it be impeachable, if it enunciates simply a result or compound of A and B, without specifying the manner of composition; it ought to declare not merely the parts of the compound, but also the way in which they are put together to form the compound.333

c. Lastly, suppose the definition to declare that the definiend is A along with B. You will note, first, that this third head must be identical either with the first or with the second (e.g., honey with water means either honey and water, or the compound of honey with water); it will therefore be open to impeachment on one or other of the above-named grounds of objection, according as the respondent may admit.334 You may also distinguish all the different senses in which one thing may be said to be with another (e.g., when the two are in the same recipient, justice and courage together in the soul; or in the same place; or in the same time), and you may be able to show that in none of these senses can the two parts of the definition be truly said to be one along with the other.335 Or, if it be true that these two parts are co-existent in time, you may enquire whether they are not affirmed with relation to different correlates. E.g., The definition of courage may be tendered thus: Courage is daring along with right intelligence; upon which you may remark that daring may have reference to an act of spoliation, and that right intelligence may have reference to the preservation of health. Now a man who has both daring and right intelligence in these senses, cannot be termed courageous, and thus you will have an argument against the definition. And, even if they be affirmed with reference to the same correlate (e.g., the duties of a physician), a man who has both daring and right intelligence 348in reference to these duties will hardly be styled courageous; the term courage must be so defined as to have reference to its appropriate end; e.g., the dangers of war, or any still more public-spirited end.336 Another mistake may, perhaps, be committed in this same sort of definition — A along with B; as when, for example, the definition tendered of anger is — pain along with the belief of being treated with contempt. What the definer really intends here is, that the pain arises from the belief of being treated with contempt. But this is not expressed by the terms of his definition, in any one of their admissible meanings.337

34. Perhaps the definition, while including two or more distinct parts, may be tendered in this form: The definiend is the composition of A and B; e.g., animal is the composition of soul and body. You will first note that the definer has not declared what sort of composition. There is a great difference between one mode of composition and another; the mode must be specialized. Both flesh and bone may be defined — a composition of fire, earth, and water; but one mode of composition makes flesh, another makes bone, out of these same elements. You may also take the farther objection that to define a compound as composition is erroneous; the two are essentially disparate, one of them being abstract, the other concrete.338

35. If the definiend be in its nature capable of receiving two contrary attributes, and if the respondent define it by one or other of them, you have an argument against him. If one of them is admissible, the other must be equally so; and upon this supposition there would be two distinct definitions of the same subject; which has been already declared impossible. Thus, it is wrong to define the soul as a substance which is recipient of knowledge; the soul is also recipient of ignorance.339

36. Perhaps the definiend is not sufficiently well known to enable you to attack the definition as a whole, but you may find arguments against one or other of its parts; this is sufficient to upset it. If it be obscure and unintelligible, you should help to correct and re-model it until it becomes clear; you will then see what are the really assailable points in it. When you indicate and expose the obscurity, the respondent must either substitute some clearer exposition of his own meaning, or else he must acquiesce in that which you propose 349as substitute.340 If the improved definition which you propose is obviously clearer and better, his previous definition is of course put out of court; since there cannot be several definitions of the same subject.341

To conclude, one suggestion may be given bearing upon all the arguments that you have to carry on against definitions tendered by respondents:— Reflect on the definiend, and frame a definition of it for yourself, as cleverly as you can at the moment; or call to mind any good definition of it which you may have heard before. This will serve you as a standard with which to compare the definition tendered, so that you will see at once what there is in it either defective or redundant, and where you can find arguments against it.342

VII.

In the Seventh Book of the Topica Aristotle continues his review of the manner of debating theses which profess to define, but enters also on a collateral question connected with that discussion: viz., By what arguments are we to determine whether two Subjects or Predicates are the same Numero (modo maxime proprio), as distinguished from being the same merely Specie or Genere? To measure the extent of identity between any two subjects, is important towards the attack and defence of a definition.343

Two subjects (A and B) being affirmed as the same numero, you may test this by examining the Derivatives, the Co-ordinates, and the Opposites, of each. Thus, if courage is identical with justice, the courageous man will be identical with the just man; courageously will be identical with justly. Likewise, the opposite of courage (in all the four modes of Opposition) will be identical with the opposite of justice. Then, again, the generators and destroyers, the generations and destructions, of courage, will be identical with those of justice.344 If there be any predicate applied to courage in the superlative degree, the same predicate 350will also be applied to justice in the superlative degree.345 If there be a third subject C with which A is identical, B also will be identical therewith. The same attributes predicable of A will also be predicable of B; and, if the two be attributes, each will be predicable of the same subjects of which the other is predicable. Both will be comprised in the same Category, and will have the same genus and differentia. Both will increase or diminish under the same circumstances. Each, when added to or subtracted from any third subject, will yield the same result.346

Farther, in examining the thesis (A is identical numero with B) you must look not merely whether it involves actually any impossible consequences, but also whether any cases can be imagined in which it would involve such;347 whether the identity is not merely specie or genere; finally, whether the one can exist without the other.348

Such are the various loci available for argument against the thesis affirming the equivocal predicate same. All of them may be useful when you are impugning a definition; for the characteristic of this is to declare that the defining proposition is equivalent or identical with the defined name; and, if you can disprove such identity, you upset the definition. But these loci will be of little avail, if your task is to defend or uphold a definition; for, even if you succeed in establishing the above-mentioned identity, the definition may still be open to attack for other weaknesses or defects.349

To uphold, or prove by way of syllogism, requires a different procedure. It is a task hard, but not impossible. Most disputants assume without proving their definition, in the same 351way as the teachers of Geometry and Arithmetic do in their respective sciences. Aristotle tells us that he does not here intend to give a didactic exposition of Definition, nor of the proper way of defining accurately or scientifically. To do this (he says) belongs to the province of Analytic; while in the present treatise he is dealing merely with Dialectic. For the purposes, then, of Dialectic, he declares that syllogistic proof of a definition is practicable, inasmuch as the definition is only a proposition declaring what is essential to the definiend; and nothing is essential except genus (or genera) and differentiæ.350

Towards the establishment of the definition which you have to defend, you may find arguments by examining the Contraries and Opposites of the component terms, and of the defining proposition. If the opposite of the definition is allowed as defining properly the opposite of the definiend, you may argue from hence that your own definition is a good one.351 If you can show that there is declared in your definition a partial correspondence of contraries either separately in the genus, or separately in the differentia, you have a certain force of argument in your favour; and, if you can make out both the two separately, this will suffice for your entire definition.352 You may also draw arguments from the Derivatives, or Co-ordinates of your own terms; from Analogous Terms, or from Comparates (More or Less). If the definition of any one of these is granted to you, an argument is furnished for the defence of an analogous definition in the case of your own term. If it is conceded as a good definition that forgetfulness is — the casting away of knowledge, then the definition must also hold good that to forget is — to cast away knowledge. If destruction is admitted to be well defined — dissolution of essence, then to be destroyed is well defined — to be dissolved as to essence. If the wholesome may be defined — that which is productive of health, then also the profitable may be defined — that which is productive of good; that is, if the declaration of the special end makes a good definition in one case, so it will also in the other.353

352These loci, from Analoga, from Derivatives, from Conjugates, are of the most frequent avail in dialectical debates or definitions. The disputant must acquire promptitude in the employment of them. He must learn, moreover, to test a definition tendered to him by calling to mind particulars and sub-species, so as to determine whether the definition fits them all. Such a procedure will be found especially serviceable in debate with one who upholds the Platonic Ideas. Care must also be taken to see whether the definiend is distorted from its proper signification, or whether it is used in defining itself.354

These last observations are addressed to the questioner or assailant of the definition. We have already seen however that his task is comparatively easy; the grand difficulty is to defend a definition. The respondent cannot at once see what he ought to aim at; and, even when he does see it, he has farther difficulty in obtaining the requisite concessions from his opponent, who may decline to grant that the two parts of the definition tendered are really the genus and differentia of the definiend; while, if there be any thing besides these two parts contained in the essence of the definiend, there is an excuse for declining to grant it.355 The opponent succeeds, if he can establish one single contradictory instance; accordingly, a syllogism with particular conclusion will serve his purpose. The respondent on the other hand, must meet each one of these instances, must establish an universal conclusion, and must show that his definition reciprocates with the definiend, so that, wherever the latter is predicable, the former is predicable likewise, and not in any other case whatever.356

So much greater are the difficulties belonging to the defence of a Definition, as compared with the attack upon it; and the same may be said about attack and defence of a Proprium, and of a Genus. In both cases, the assailant will carry his point, if he can show that the predicate in question is not predicable, in this relation, of all, or that it is not predicable, in this relation, of any one. But the defendant is required to make good the universal against every separate objection advanced against any one of the particulars. It is a general rule, that the work of destruction is easier than that of construction; and the present cases come under that rule.357 The hardest of all theses to defend, 353and the easiest to overthrow, is where Definition is affirmed; for the respondent in this case is required to declare well the essence of his subject, and he stands in need of the greatest number of auxiliary data; while all the Loci for attack, even those properly belonging to the Proprium, the Genus, and the Accident, are available against him.358 Next in order, as regards difficulty of defence, comes the theses affirming Proprium; where the respondent has to make out, not merely that the predicate belongs to the subject, but that it belongs thereunto exclusively and reciprocally: here also all the Loci for attack, even those properly belonging to Accident, are available.359 Easiest of all theses to defend, while it is the hardest to impugn, is that in which Accident alone is affirmed — the naked fact, that the predicate A belongs to the Subject B, without investing it with the character either of Genus or Proprium. Here what is affirmed is a minimum, requiring the smallest array of data to be conceded; moreover, the Loci available for attack are the fewest, since many of those which may be employed against Genus, Proprium, and Definition, have no application against a thesis affirming merely Accident.360 Indeed, if the thesis affirmed be only a proposition particular (and not universal), affirming Accident (and nothing more), the task of refuting it will be more difficult than that of maintaining it.361

VIII.

The Eighth Book of the Topica brings our attention back to the general considerations contained in the First. In the intervening part of the treatise we have had the quadruple distribution of dialectical problems, with the enumeration of those Loci of argument which bear upon each or all: we are now invited to study the application of these distinctions in practice, and with this view to look once more both at the persons and the purposes of dialectical debate. What is the order of procedure most suitable, first, for the questioner or assailant; next, for the respondent or defender?362 This order of procedure marks 354the distinctive line of separation between the dialectician and the man of science or philosopher: to both of them the Loci of arguments are alike available, though each of them deals with those arguments in his own way, and in an arrangement suitable for his purpose.363 The dialectician, being engaged in debate, must shape his questions, and regulate his march as questioner, according to the concessions obtained or likely to be obtained from his respondent; who, if a question be asked having an obvious refutative bearing on the thesis, will foresee the consequences of answering in the affirmative, and will refuse to grant what is asked. On the contrary, the philosopher, who pursues investigation with a view to his own satisfaction alone, is under no similar restriction. He looks out at once for such premisses as conduct straight to a conclusion; and, the more obvious their bearing on the conclusion is, the more scientific will the syllogism be, and the better will he be pleased.364

In the praxis dialectica (as has already been stated) two talkers are assumed — the respondent who sets up a thesis which he undertakes to defend, and a questioner who interrogates with a view to impugn it; or at least with a view to compel the other to answer in an inconsistent or contradictory manner. We are to assume, farther, a circle of listeners, who serve to a certain extent as guarantees against any breach of the rules of debate.365 Three distinct purposes may be supposed in the debate. 1. You as a questioner may be a teacher, and the respondent a learner; your purpose is to teach what you know, while he wishes to learn from you what he does not know. 2. You engage in an intellectual contest or duel with the respondent, each of you seeking only victory over the other, though subject on both sides to observance of the rules of debate. 3. You neither seek to teach, nor to conquer; you and the respondent have both the same purpose — to test the argumentative consequences of different admissions, and to acquire a larger command of the chains of reasoning pro and con, bearing on some given topic.366

According as the aim of the talkers is one or other of these three, the good or bad conduct of the dialogue, on the part both of questioner and of respondent, must be differently appreciated. Of each of the three, specimens may be found in Plato, though not carefully severed but running one into the other. Aristotle 355appears to have been the first to formulate the distinction theoretically, and to prescribe for the practice of each separately. He tells us particularly that no one before him had clearly distinguished the third head, and prescribed for it apart from the second. The merit of having first done this he expressly claims for the Topica.367

Both the questioner and the respondent have a duty towards the dialogue; their common purpose is to conduct it well, not only obeying the peremptory rules, but displaying, over and above, skill for the attainment of their separate ends. Under the first and third heads, both may be alike successful. Under the second or contentious head, indeed, one only of the two can gain the victory; yet, still, even the defeated party may exhibit the maximum of skill which his position admits. This is sufficient for his credit; so that the common work will still be well performed.368 But a partner who performs his own part so as to obstruct instead of forwarding this common work — who conducts the debate in a spirit of ill-tempered contention rather than of regular Dialectic — deserves censure.369

Having thus in view the dialogue as a partnership for common profit, Aristotle administers counsel to the questioning as well as to the responding partner. You as questioner have to deal with a thesis set up by the respondent. You see at once what the syllogism is that is required to prove the contrary or contradictory of that thesis; and your business is so to shape your questions as to induce the respondent to concede the premisses necessary towards that syllogism. If you ask him at once and directly to concede these premisses, he sees your drift and answers in the negative. You must therefore begin your approaches from a greater distance. You must ask questions bearing only indirectly and remotely upon your ultimate conclusion.370 These outlying and preparatory questions will fall under four principal heads. Either (1) they will be inductive particulars, multiplied in order that you may obtain assent to 356an universal comprising them all; or (2) they will be put for the purpose of giving dignity to your discourse; or (3) they will be shaped with a view to conceal or keep out of sight the ultimate conclusion that you aim at; or (4), lastly, they will be introduced to make your whole argument clearer.371 The third of these four general heads — the head of questions for the purpose of concealment — comes out principally in dialectical contests for victory. In those it is of supreme importance, and the result depends much on the employment of it; but even in other dialectical debates you must employ it to a certain extent.372

Aristotle goes at great length into the means of Concealment. Suppose the proposition which you desire to get conceded is, The science of two contraries is the same. You will find it useful to commence by a question more general: e.g., Is the science of two opposites the same? If the respondent answers in the affirmative, you will deduce from his concession, by syllogism, the conclusion which you desire. If he answers in the negative, you must then try to arrive at your end by a string of questions respecting particular contraries or opposites; which if the respondent grants successively, you will bring in your general question ultimately as the inductive result from those concessions.373 Your particulars must be selected from obvious matters of sense and notoriety. You are likely to obtain in this way admissions which will serve as premisses for several different prosyllogisms, not indeed sufficient by themselves, yet valuable as conditions and preliminaries to the final syllogism whereby the thesis is refuted. For, when the questions are put in this way, the respondent will not see your drift nor the consequences of his own concessions; so that he will more readily concede what you want.374 The better to conceal your purpose, you will refrain from drawing out any of these prosyllogisms clearly at once; you will not even put the major and minor premiss of any one of them in immediate sequence; but you will confound the order of them intentionally, stating first a premiss belonging to one, and next a premiss belonging to another.375 The respondent, thus kept in the dark, answers in the affirmative to each of your questions successively. At length you find that you have obtained a sufficient number of concessions from him, 357to enable you to prove the syllogism contradictory of his thesis. You inform him of this; and it shows the perfect skill and success of your procedure, when he expresses surprise at the announcement, and asks on what premisses you reckon.376

There are also other manœuvres serving your purpose of concealment, and preventing the respondent from seeing beforehand the full pertinence of your questions. Thus, if you wish to obtain the definition of your major, you will do well to ask the definition, not of the term itself but, of some one among its conjugates. You will put your question, as if the answer were of little importance in itself, and as if you did not care whether it was given in the affirmative or in the negative;377 you will sometimes even suggest objections to that which you are seeming to aim at. All this will give you the air of a candid disputant; it will throw the respondent off his guard, and make him more ready to answer as he really thinks, without alarm for the consequences.378 When you wish to get a certain premiss conceded, you will put the question first upon a different premiss analogous to it. In putting your question, you will add that the answer which you desire is a matter of course, familiar and admitted by every one; for respondents are shy of contradicting any received belief, unless they have present to their minds a clear instance adverse to it.379 You will never manifest apparent earnestness about an answer; which would make the respondent less willing to concede it.380 You will postpone until the last the premiss which you wish to obtain, and will begin by putting questions the answers to which serve as remote premisses behind it, only in the end conducting to it as consequence. Generally speaking, questioners do the reverse, putting first the questions about which they are most anxious; while most respondents, aware of this habit, are most intractable in regard to the first questions, except some presumptuous and ill-tempered disputants, who concede what is asked at first but afterwards become obstinate in denegation.381 You will throw in some irrelevant questions with a view to lengthen the procedure, like 358fallacious geometers who complicate a diagram by drawing unnecessary lines. Amidst a multitude of premisses falsehood is more likely to escape detection; and thus, also, you may perhaps be able to slip in, unperceived and in a corner, some important premiss, which, if put as a separate question by itself, would certainly not have been granted.382

Such are the multifarious suggestions addressed by Aristotle to the questioner for concealing his method of attack;383 Concealment being the third of the four general heads relating to the treatment of premisses not immediately necessary for proof of the final refutative conclusion. On the other three general heads — Induction from particulars to an universal, Dignity, Clearness — Aristotle goes into less detail. For Clearness, he recommends that examples should be introduced; especially familiar examples, taken from well-known poets like Homer, not from obscure poets like Chœrilus.384

In regard to Induction, Aristotle points out an embarrassment often arising from the want of suitable universal names. When, after having obtained an affirmative answer about several similar particulars, you wish to put a question generalizing the result, you will sometimes find no universal term fitting the position. You are obliged to say: Will it not be so in all such cases? and this lets in a serious difficulty, how to know what other cases are like, and what are not. Here the respondent will often dispute your right to include this or that other particular.385 You will do well to coin a new universal term fitting the situation.

If the respondent answers in the affirmative to several questions of similar particulars, but answers in the negative when you sum them up in an universal comprehending all similar cases, — you may require him to cite some particular case justifying his denial; though you cannot require him to do this before he has made the affirmative answers.386 It is not sufficient that he should cite, as the single case of exception, the express case which forms the subject of the thesis: He ought to produce some distinct and independent instance, really comprised within the genus, and not merely connected with it by the link of an equivocal term.387 If he produces an adverse instance really comprised359 within the genus, you may perhaps be able to re-model your question, so as to make reserve for the basis on which this objection is founded. The respondent will then be compelled (unless he can foresee some new case of objection) to concede the universal with this special qualification; so that you will have gained all that you really require. Should the respondent continue to refuse, without producing any new case, he will transgress the rules of Dialectic; which recognize an universal affirmative, wherever there are numerous affirmative particulars without one assignable negative.388 Indeed, if you know the universal to hold in many particular cases, and do not know of any others adverse, you may boldly put your question at once in reference to the universal (without going first through the series of particulars). The respondent will hardly venture to deny it, not having in his mind any negative particulars.389

You must however keep in mind what a dialectic universal premiss really is. Not every question requiring an universal answer is allowed to be put. You must not ask for positive information, nor put such questions as the following: What is man? In how many different senses is good employed? A dialectic question is one to which the respondent makes sufficient reply by saying, Yes or No.390 You must ask in this form: Is the definition of man so and so? Is good enunciated in this or that different sense? To these questions the respondent may answer Yes or No. But if he persists in negative answers to your multiplied questions as to this or that sense of the term good, you may perhaps stand excused for asking him: “In how many different senses, then, do you yourself use the term good?”391

When you have obtained concessions which furnish premisses for a formal syllogism, you will draw out and propound that syllogism and its conclusion forthwith, without asking any farther question from the respondent or any leave from him to do so. He may indeed deny your right to do this, in spite of the concessions which he has made; and the auditors around, not fully appreciating all his concessions, may perhaps think that he is entitled to deny it. But, if you ask his leave to draw out the syllogism and he refuses to give leave, the auditors are much more likely to think that your syllogism is not allowable.392 If 360you have the choice between an ostensive syllogism and a Reductio ad Absurdum, you ought always to prefer the former, as plainer and more incontestable.393

You must not persevere long in the same line of questions. For, if the respondent answers them all, it will soon appear that you are in the wrong course, since your syllogism, if you can get one at all, will always be obtained from a small number of premisses; and, if the respondent will not answer them, you have no alternative except to protest and desist.394

The theses that are most difficult to attack are also most easy to defend; and these are the highest universals, and the lowest particulars. The highest you cannot deal with, unless you can get a definition of them; which is sometimes impossible and always difficult; since the respondent will neither define them himself nor accept your definitions. Those which are next to the highest are also difficult to impugn, because there are few intermediate steps of proof. Again, the lowest particulars are also difficult for the contrary reason, that there are so many intermediate steps, and it is tedious to enumerate them all continuously; while, if any are omitted, the demonstration is incomplete, and the procedure will appear sophistical.395 The most difficult of all to impugn are definitions framed in vague and unintelligible terms, where you do not know whether they are univocal or equivocal, literal or metaphorical. When the thesis tendered to you presents such difficulty, you may presume that it is affected with the obscurity of terms here indicated; or, at any rate, that its terms stand in need of definition.396 In geometrical construction, as well as in dialectical debate, it is indispensable that the principia or primary terms should be defined, and defined properly; without this, neither the one nor the other can be pursued.397

Sometimes the major and minor premisses of your syllogistic conclusion are more difficult to establish — more beyond the level of average intelligence — than the thesis itself. In such a case some may think that the respondent ought to grant these premisses, because, if he refuses and requires them to be proved, he will be imposing upon the questioner a duty more arduous than the thesis itself imposes; others may say that he ought not to grant them, because, if he did, he would be acknowledging a conclusion derived from premisses requiring proof as much or 361more than itself.398 A distinction must here be made. If you are putting questions with a view to teach, the learner ought not to grant such premisses as those above described, because he is entitled to require that in every step of the process he shall be inducted from what is more knowable to what is less knowable. Accordingly, when you attempt to demonstrate to him something which he knows little, by requiring him to concede something which he knows still less, he cannot be advised to grant what you ask. But, if you are debating with a companion for the purpose of dialectical exercise, he ought to grant what you ask whenever the affirmative really appears to him true.399

We have now said enough for the purpose of instructing the questioner how to frame and marshal his interrogations. We must turn to the respondent, and point out how he must answer in order to do well and perform his duty to the common work of dialogue. Speaking generally, the task of the questioner is to conduct the dialogue so as to make the respondent enunciate the most improbable and absurd replies which follow necessarily from the thesis that he has undertaken to defend; while the task of the respondent is to make it appear that these absurdities follow from the thesis itself, and not from his manner of defending it. The respondent may err in one of two ways, or indeed in both together: either he may set up an indefensible thesis; or he may fail to defend it in the best manner that it really admits; or he may do both. The second is a worse error than the first, in reference to the general purpose of Dialectic.400

Aristotle distinguishes (as has been already stated) three purposes in the dialogue:— (1) Teaching and Learning; (2) Contention, where both questioner and respondent strive only for victory; (3) Investigating and Testing the consequences of some given doctrine.401 The first two of these three are dismissed rapidly. In the first, the teaching questioner has no intention of deceiving, and the pupil respondent has only to answer by granting all that appears to him true.402 In the second, Aristotle tells us only that the questioner must always appear as if he 362were making some point of his own; while the respondent, on his side, must always appear as if no point were made against him.403 But in regard to the third head — dialogues of Search, Testing, Exercise — he is more copious in suggestions: he considers these as the proper field of Dialectic, and, as we saw, claims to have been the first who treated them apart from the didactic dialogues on one side, and the contentious on the other.404

The thesis which the respondent undertakes to defend (in a dialogue of Search or Testing) must be either probable, or improbable, or neither one nor the other. The probability or improbability may be either simple and absolute, or special and relative — in the estimation of the respondent himself or of some one or more persons. Now, if the thesis be improbable, the opposite thereof, which you the questioner try to prove, must be probable; if the thesis be probable, the opposite thereof must be improbable; if the thesis be neither, its opposite will also be neither. Suppose, first, that the thesis is improbable absolutely. In that case, its opposite, which you the questioner must fish for premisses to prove, will be probable; the respondent therefore ought not to grant you any demand which is either simply improbable or less probable than the conclusion which you aim at proving; for no such concessions can really serve your purpose, since you are bound to prove your conclusion from premisses more probable than itself.405 Suppose, next, that the thesis is probable absolutely. In that case, the opposite conclusion, which you have to make out, will be improbable absolutely. Accordingly, whenever you ask concessions that are probable, the respondent ought to grant them; whenever you ask for concessions that are less improbable than your intended conclusion, he ought to grant these also; but, if you ask for any thing more improbable than your intended conclusion, he ought to refuse it.406 Suppose, thirdly, that the thesis is neither probable nor improbable. Here, too, the respondent ought to grant all concessions that appear to him probable, as well as all that he thinks more probable than the opposite conclusion which you 363are seeking to arrive at; but no others. This is sufficient for the purpose of Dialectic, and for keeping open the lines of probable argument.407

When the probability or improbability of the thesis is considered simply and absolutely, the respondent ought to measure his concessions by the standard of opinion received usually.408 When the probability or improbability of the thesis is considered as referable to the respondent himself, he has only to consult his own judgment and estimation in granting or refusing what is asked. When he undertakes to defend a thesis avowedly as the doctrine of some known philosopher, such as Herakleitus, he must, in giving his answers, measure probability and improbability according to what Herakleitus would determine.409

Since all the questions that you ask must be either probable, improbable, or neuter, and either relevant410 or not relevant to your purpose of refuting the thesis, let us first suppose that you ask for a concession which is in itself probable, but not relevant. The respondent ought to grant it, adding that he thinks it probable. If what you ask is neither probable nor relevant, he ought even then to grant it; but annexing a notification that he is aware of its improbability, in order to save his own credit for intelligence.411 If it be both probable and relevant, he ought to say that he is aware of its probability, but that it is too closely connected with the thesis, and that, if he grants it, the thesis will stand refuted. If it be relevant, yet at the same time very improbable, he must reply that, if he grants it, the thesis will be refuted, but that it is too silly to be propounded. If, being neutral, it is also not relevant, he ought to grant it without comment; but if, being neutral, it is relevant, he ought to notify that he is aware that by granting it his thesis will be refuted.412

In this way of proceeding, the march of the dialogue on both sides will be creditable. The respondent, signifying plainly that he understands the full consequences of his own concessions, will not appear to be worsted through any short-comings of his 364own, but only through what is inherent in his thesis; while you the questioner, having asked for such premisses as are really more probable than the conclusion to be established, and having had them granted, will have made out your point. It must be understood that you ought not to try to prove your conclusion from premisses less probable than itself; and that, if you put questions of this sort, you transgress the rules of dialectical procedure.413

If you ask a dialectical question in plain and univocal language, the respondent is bound to answer Yes or No. But if you ask it in terms obscure or equivocal, he is not obliged to answer thus directly. He is at liberty to tell you that he does not understand the question; he ought to have no scruple in telling you so, if such is really the fact. Suppose the terms of your question to be familiar, but equivocal; the answer to it may perhaps be either true or false, alike in all the different senses of the terms. In that case, the respondent ought to answer Yes or No directly. But, if the answer would be an affirmation in one sense of the terms and a negation in another, he must take care to signify that he is aware of the equivocation, and to distinguish at once the two-fold meaning; for, if the distinction is not noticed till afterwards, he cannot clearly show that he was aware of it from the first. If he really was not at first aware of the equivocation, and gave an affirmative answer looking only to one among the several distinct meanings, you will try to convict him of error by pushing him on the other meaning. The best thing that he can then do will be to confess his oversight, and to excuse himself by saying that misconception is easy where the same term or the same proposition may mean several different things.414

Suppose you put several particular questions (or several analogous questions) with the view of arriving ultimately by induction at the concession of an universal, comprising them all. If they are all both true and probable, the respondent must concede them all severally; yet he may still intend to answer No, when the universal is tendered to him after them. He has no right to answer thus, however, unless he can produce some contradictory particular instance, real or apparent, to justify him; and, if he does so without such justification, he is a perverse 365dialectician.415 Perhaps he may try to sustain his denegation of the universal, after having conceded many particulars, by a counter-attack founded on some chain of paradoxical reasoning such as that of Zeno against motion; there being many such paradoxes contradictory of probabilities, yet hard to refute. But this is no sufficient justification for refusing to admit the universal, when, after having admitted many particulars, he can produce no particular adverse to them. The case will be still worse, if he refuses to admit the universal, having neither any adverse instance, nor any counter-ratiocinative attack. It is then the extreme of perverse Dialectic.416

Before the respondent undertakes to defend any thesis or definition, he ought to have previously studied the various modes attacking it, and to have prepared himself for meeting them.417 He must also be cautious of taking up improbable theses, in either of the senses of improbable. For a thesis is so called when it involves strange and paradoxical developments, as if a man lays down either that every thing is in motion or that nothing is in motion; and also, when it implies a discreditable character and is contrary to that which men wish to be thought to hold, as, for example, the doctrine that pleasure is the good, or that it is better to do wrong than to suffer wrong. If a man defends such theses as these, people hate him because they presume that he is not merely propounding them as matter for dialectical argument, but advocating them as convictions of his own.418

The respondent must farther be able, if you bring against him a false syllogistic reasoning, to distinguish upon which among your premisses the false conclusion really turns, and to refute that one. Your reasoning may have more than one false premiss; but he must not content himself with refuting any one or any other: he must single out that one which is the chief determining cause of the falsehood. Thus, if your syllogism be:— Every man in a sitting position is writing, Sokrates is a man in a sitting position; therefore, Sokrates is writing, — it will not suffice that the respondent should refute your minor premiss, 366though this may be false;419 because such a refutation will not apply to the number of other cases in which men are sitting but not writing; and therefore it will not expose the full bearing of the falsehood. Your major premiss is that upon which the full bearing of the falsehood depends; and the respondent must show that he is aware of this by refuting your major.420

This last-mentioned proceeding — refutation of that premiss upon which your false conclusion in its full bearing really turns — is the only regular, valid, and complete objection whereby the respondent can stop out your syllogistic approaches. There are indeed three other modes of objection to which he may resort; but these are all either inconclusive or unfair. He may turn his objection against you personally; and, without refuting any of your premisses, he may thus perplex and confuse you, so that you are disqualified from pursuing the thread of your questions. Or he may turn his objections against portions of your questions; not refuting any one of your premisses, but showing that, as they stand, they are insufficient to warrant the conclusion which you seek to establish; when, if you are master of your subject, and retain your calmness, you will at once supply the deficiency by putting additional questions, so that his objection thus vanishes. Or, lastly, he may multiply irrelevant objections against time, for the purpose of prolonging the discussion and tiring you out.421 Of these four modes of objection open to the respondent the first is the only one truly valid and conclusive; the three others are obstructions either surmountable or unfair, and the last is the most discreditable of all.422

To blame the argumentative procedure and to blame the questioner are two distinct things. Perhaps your manner of conducting the interrogation, preparatory to your final syllogism, may be open to censure; yet nevertheless you the questioner may deserve no censure; for it may be the respondent’s fault, not yours. He may refuse to grant the very premisses which are essential to the good conduct of your case; he may resort to perverse evasions and contradictions for the mere purpose of 367thwarting you; so that you are forced to adapt yourself to his unworthy manœuvres rather than to aim at the thesis itself. Dialectic cannot be well conducted unless both the partners do their duty to the common purpose; the bad conduct of your respondent puts you out, and the dialectic presently degenerates on both sides into angry contention.423 Apart from this, too, it must be remembered that the express purpose of Dialectic is not to teach, but to search and test consequences and to exercise the intellect of both parties. Accordingly you are not always restricted to true syllogistic premisses and conclusions. You are allowed to resort occasionally to false premisses and false conclusions; for, if what the respondent advances be true, you have no means of refuting it except by falsehood; and, if what he advances be false, the best way of refuting it may be through some other falsehood.424 You render service to him by doing so; for, since his beliefs are contrary to truth, if the dialogue is confined to his beliefs, the result may perhaps contribute to persuade him, but it will not instruct or profit him.425 It is your business to bring him round and emancipate him from these erroneous beliefs; but you must accomplish this in a manner truly dialectical, and not contentious; whether you proceed by true or by false conclusions.426 If you on your side, indeed, put questions in a contentious spirit, it is you that are to blame. But often the respondent is most to blame, when he refuses to grant what he thinks probable, and when he does not apprehend what you really intend to ask.427 He is sometimes also to blame for granting what he ought to refuse; such as Petitio Principii or Affirmation of Contraries. It is often difficult to distinguish what questions involve Petitio Principii or Affirmation of Contraries: they are asked and granted without either party being aware, and the like mistake is committed by men in private talk, not merely in formal dialogue. When this happens, the argument will inevitably be a bad one; but the fault is with the 368respondent who, having before refused what he ought to have granted, now grants what he ought to refuse.428

Such then are the cases in which the conduct of the dialogue is open to censure, without any fault on your part as questioner. But there are other cases in which the fault is really yours. These are five in number:— (1) When all or most of your questions are so framed as to elicit premisses either false or improbable, so that neither the conclusion which you seek to obtain, nor any other conclusion at all, follows from them; (2) When, from similar defects, the proper conclusion that you seek to obtain cannot be drawn from your premisses; (3) When the proper conclusion would follow, if certain additions were made to your premisses, but such additions are of a character worse than the premisses already obtained, and are even less probable than the conclusion itself; (4) When you have accumulated a superfluous multitude of premisses, so that the proper conclusion does not follow from all of them but from a part of them only (5) When your premisses are more improbable and less trustworthy than the proper conclusion, or when, though true, they are harder and more troublesome to prove than the problem itself.429

In regard to the last item, however, the fault may sometimes be in the problem itself rather than in you as questioner. Some problems, being in their own nature hard and not to be settled from probable or plausible data, ought not to be admitted into Dialectic. All that can be required from you as questioner is that you shall know and obtain the most probable premisses that the problem admits: your procedure may be thus in itself blameable, yet it may even deserve praise, having regard to the problem, if this last be very intractable; or it may be in itself praiseworthy, yet blameable in regard to the problem, if the problem admit of being settled by premisses still more probable.430 You may even be more blameable, if you obtain your conclusion but obtain it from improbable premisses, than if you failed to obtain it; the premisses required to make it complete being true and probable and not of capital importance, but being refused by the respondent.431 However, you ought not 369to be blamed if you obtain your true and proper conclusion but obtain it through premisses in themselves false; for this is recognized in analytical theory as possible: if the conclusion is false, the premisses (one or both) must be false, but a true conclusion may be drawn from false premisses.432

When you have obtained your premisses and proved a conclusion, these same premisses will not serve as proof of any other proposition separate and independent of the conclusion; such may sometimes seem to be the case, but it is a mere sophistical delusion. If your premisses are both of them probable, your conclusion may in some cases be more probable than either.433

One other matter yet remains in which your procedure as questioner may be blameable. The premisses through which you prove your conclusion may be long and unnecessarily multiplied; the conclusion may be such that you ought to have obtained it through fewer, yet equally pertinent premisses.434

The cases in which your argument will carry the clearest evidence, impressing itself even on the most vulgar minds, are those in which you obtain such premisses as will enable you to draw your final conclusion without asking any farther concessions. But this will rarely happen. Even after you have obtained all the premisses substantially necessary to your final 370conclusion, you will generally be forced to draw out two or more prosyllogisms or preliminary syllogisms, and to ask the assent of the respondent to these, before you can venture to enunciate the final conclusion. This second grade of evidence is however sufficient, even if the premisses fall short of the highest probability.435

On the other hand, your argument may deserve to be pronounced false on four distinct grounds:— (1) If your syllogism appears to prove the conclusion but does not really prove it, being then an eristic or contentious syllogism; (2) If the conclusion be good but not relevant to the thesis, which is most likely to happen where you employ Reductio ad Impossible; (3) If your conclusion though valid and even relevant, is not founded on the premisses and principia appropriate to the thesis; (4) If your premisses are false, even though the conclusion in itself may prove true, since it has already been said that a true conclusion may sometimes be obtained from false premisses.436

Falsehood in your argument will be rather your own fault than that of your argument, especially if you yourself are not aware of its falsehood. Indeed, there are some false arguments which are more valuable in Dialectic than many true ones; where, for example, from highly probable premisses you refute some recognized truth. Such an argument is sure to serve as a demonstration of other truths; at the very least, it shows that some one of the propositions concerned is altogether untrue.437 On the other hand, if you prove a true conclusion by premisses false and improbable, your argument will be more worthless than many others in which the conclusion is false; from such premisses, indeed, the conclusion may well be really false.438

In estimating the dialectical value of an argument, therefore, we must first look whether the conclusion is formally valid; next, whether the conclusion is true or false; lastly, what are the premisses from whence it is derived.439 For, if it be derived from premisses false yet probable, it has logical or dialectical 371value; while, if derived from premisses true yet improbable, it has none.440 If derived from premisses both false and improbable, it will of course be worthless; either absolutely in itself, or with reference to the thesis under debate.

Two faults of questioners in Dialectic are dealt with specially by Aristotle:— (1) Petitio Principii; (2) Petitio Contrariorum. He had touched upon both of them (in the Analytica Priora) as they concerned the demonstrative process, or the proving of truth: he now deals with them as they concern the dialectical process, or the setting out of opinions and probabilities.441

Five distinct modes may be enumerated of committing the fault called Petitio Principii:—

1. You may put as a question the very conclusion which it is incumbent on you to prove, in refutation of the thesis of the respondent. If this is done in explicit terms, your opponent can hardly fail to perceive it; but he possibly may fail, if you substitute an equivalent term or the definition in place of the term.442

2. If the conclusion which you are seeking to prove is a particular one, you may put as a question the universal in which it is comprised. Thus, if you are to prove that the knowledge of Contraries is one and the same, you may put as a question, Is not the knowledge of Opposites one and the same? You are asking the very point which it was your business to show; but you are asking along with it much more besides.443

3. If you are seeking to prove an universal conclusion, you may put as a question one of the particulars comprised therein. Thus, if you are to prove that the knowledge of Contraries is one and the same, you may put as a question, Is not the knowledge of white and black, good and evil, or any other pair of particular contraries, one and the same? It was your business to prove this particular, along with many others besides; but you are now asking it as a question separately.444

4. If the conclusion which you are seeking to prove has two terms conjointly, you may put as a question one or the other of these separately. Thus, when you are trying to show that the healing art is knowledge of what is wholesome and unwholesome, you may ask, Is it a knowledge of the wholesome?445

3725. Suppose there are two conclusions necessarily implicated with each other, and that it is your business to prove one of them: you may put as a question the other of the two. Thus, if you are seeking to prove that the diagonal is incommensurable with the side, you may put as a question, Is not the side incommensurable with the diagonal?446

There are also five distinct modes of Petitio Contrariorum:—

1. You may ask the respondent, in plain terms, to grant first the affirmative, next, the negative, of a given proposition.447

2. You may ask him to grant, first, that a given subject is, e.g., good, next, that the same subject is bad.448

3. After he has granted to you the affirmative universally, you may ask him to grant the negative in some particular case under the universal: e.g., after he has granted that the knowledge of Contraries is one and the same, you ask him to grant that the knowledge of wholesome and unwholesome is not one and the same. Or you may proceed by the way of reversing this process.449

4. You may ask the contrary of that which follows necessarily from the premisses admitted.450

5. Instead of asking the two contraries in plain and direct terms, you may ask the two contraries in different propositions, yet necessarily implicated with the first two.451

There is this difference between Petitio Principii, and Petitio Contrariorum: the first has reference to the conclusion which you have to prove, and the wrong procedure involved in it is relative to that conclusion; but in the second the wrong procedure affects only the two propositions themselves and the relation subsisting between them.452

Aristotle now, finally, proceeds to give some general advice for exercise and practice in Dialectic. You ought to accustom yourself to treat arguments by converting the syllogisms of which they consist; that is, by applying to them the treatment of which the Reductio ad Absurdum is one case.453 You ought to test every thesis by first assuming it to be true, then assuming it to be false, and following out the consequences on 373both sides.454 When you have hunted out each train of arguments, look out at once for the counter-arguments available against it. This will strengthen your power both as questioner and as respondent. It is indeed an exercise so valuable, that you will do well to go through it by yourself, if you have no companion.455 Put the different trains of argument, bearing on the same thesis, into comparison with each other. A wide command of arguments affirmative as well as negative will serve you well both for attack and for defence.456

This same accomplishment will be of use, moreover, for acquisitions even in Science and Philosophy. It is a great step to see and grasp in conjunction the trains of reasoning on both sides of the question; the task that remains — right determination which of the two is the better — becomes much easier. To do this well, however, — to choose the true and to reject the false correctly — there must be conjoined a good natural predisposition. None but those who are well constituted by nature, who have their likings and dislikes well set in regard to each particular conjuncture, can judge correctly what is best and what is worst.457

In regard to the primary or most universal theses, and to those problems which are most frequently put in debate, you will do well to have reasonings ready prepared, and even to get them by heart. It is on these first or most universal theses that respondents become often reluctant and disgusted. To be expert in handling primary doctrines and probabilities, and to be well provided with the definitions from which syllogisms must start, is to the dialectician an acquisition of the highest moment; like familiarity with the Axioms to a geometer, and ready application of the multiplication table to an arithmetical calculator.458 When you have these generalities and major propositions firmly established in your mind, you will recall, in a definite order and arrangement, the particular matters falling 374under each of them, and will throw them more easily into syllogisms. They will assist you in doing this, just as the mere distribution of places in a scheme for topical memory makes you recollect what is associated with each. You should lodge in your memory, however, universal major premisses rather than complete and ready-made reasonings; for the great difficulty is about the principia.459

You ought also to accustom yourself to break down one reasoning into many; which will be done most easily when the theme of the reasoning is most universal. Conceal this purpose as well as you can; and in this view begin with those particulars which lie most remote from the subject in hand.460 In recording arguments for your own instruction, you will generalize them as much as possible, though perhaps when spoken they may have been particular; for this is the best way to break down one into several. In conducting your own case as questioner you will avoid the higher generalities as much as you can.461 But you must at the same time take care to keep up some common or general premisses throughout the discourse; for every syllogistic process, even where the conclusion is particular, implies this, and no syllogism is valid without it.462

Exercise in inductive discourse is most suitable for a young beginner; exercise in deductive or syllogistic discourse, for skilful veterans. From those who are accomplished in the former you can learn the art of multiplying particular comparisons; from those who are accomplished in the latter you derive universal premisses; such being the strong points of each. When you go through a dialectical exercise, try to bring away with you for future use either some complete syllogism, or some solution of an apparent refutation, or a major premiss, or a well-sustained exceptional example (ἔνστασιν); note also whether either you or your respondent question correctly or otherwise, and on what reason such correctness or incorrectness turned.463 It is the express purpose of dialectical exercise to acquire power 375and facility in this procedure, especially as regards universal premisses and special exceptions. Indeed the main characteristic of the dialectician is to be apt at universal premisses, and apt at special exceptions. In the first of these two aptitudes he groups many particulars into one universal, without which he cannot make good his syllogism; in the second of the two he breaks up the one universal into many, distinguishing the separate constituents, and denying some while he affirms others.464

You must take care however not to carry on this exercise with every one, especially with a vulgar-minded man. With some persons the dispute cannot fail to take a discreditable turn. When the respondent tries to make a show of escaping by unworthy manœuvres, the questioner on his part must be unscrupulous also in syllogizing; but this is a disgraceful scene. To keep clear of such abusive discourse, you must be cautious not to discourse with commonplace, unprepared, respondents.465

[END OF CHAPTER IX]

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