6 Aristotle speaks of two moments of the definable form as two essential natures. His argument amounts to this: that if the conclusion contains the whole definition, the question has been begged in the premisses (cf. ii, ch. 4). Hence syllogism—and even so merely dialectical syllogism—is only possible if premisses and conclusion each contain a part of the definition.
7 ii, ch. 2.
8 The distinction is that between genuine knowledge of a connexion through its cause and accidental knowledge of it through a middle not the cause.
9 i. e. that there is no moonlight casting shadows on the earth on a clear night at full moon.
10 ii, ch. 3.
11 Cf., however, ii, ch. 2.
12 i. e. as treated by geometry; that is, as abstracted a materia and treated as a subject. Cf. 81b 25.
13 Cf. 93a 16–27.
14 Presumably a reason for there being a kind of definition other than nominal. The reference is obviously to 92b 32.
15 Demonstration, like a line, is continuous because its premisses are parts which are conterminous (as linked by middle terms), and there is a movement from premisses to conclusion. Definition resembles rather the indivisible simplicity of a point.
16 By this Aristotle appears to mean the material cause; cf. Physics ii, 195a 18, 19, where the premisses of a syllogism are said to be the material cause of the conclusion.
17 sc. ‘lest you should suppose that (2) could not be a middle’.
18 sc. ‘that (2) can appear as a middle’.
19 Cf. Euclid, Elem. i, Def. x, but Aristotle may be referring to some earlier definition. The proof here given that the angle in a semicircle is a right angle is not that of Euclid iii. 31; cf. Heath, Greek Mathematics, i. pp. 339, 340.
20 The reference is to 93a 3 ff., and other passages such as 94a 5 ff., where the middle is shown to define the major.
21 Cf. Physics vi.
22 i. e. Aristotle has had in this chapter to explain (1) how syllogisms concerning a process of events can be brought into line with other demonstrations equally derivable from immediate primary premisses, and (2) in what sense the middle term contains the cause. He has in fact had (1) to show that in these syllogisms inference must find its primary premiss in the effect, and (2) to imply that the ‘cause’ which appears as middle when cause and effect are not simultaneous is a causa cognoscendi and not essendi.
23 i, ch. 3 and An. Pr. ii, cc. 3–5, 8–10.
24 This chapter treats only the definition of substances.
25 i, ch. 4.
26 With the remainder of the chapter compare An. Pr. i, ch. 25, where the treatment covers all syllogism.
27 sc. genera and species.
28 ii, ch. 5 and An. Pr. i, ch. 31.
29 Cf. Topics iv.
30 Cf. Topics ii.
31 Here begins Aristotle’s answer.
32 Here begins Aristotle’s answer.
33 sc. broad-leaved.
34 Vine, fig, &c.
35 Broad-leaved with deciduous.
36 Aristotle contemplates four terms: (1) deciduous, (2) coagulation, (3) broad-leaved, (4) vine, fig, &c.
If we get the middle proximate to (1) it is a definition of (1). But in investigating vines, figs, &c. according to the method of chapter 13, we shall first find a common character of them in broad-leaved, and, taking this as a middle, we shall prove that vine, fig, &c., qua broad-leaved, are deciduous. But this proof is not demonstration, because broad-leaved is not a definition of deciduous. So our next step will be to find a middle—coagulation—mediating the major premiss of this proof, and demonstrate that broad-leaved plants, qua liable to coagulation, are deciduous. This is strict demonstration, because coagulation defines deciduous.
37 But cf. i, ch. 4, 73b 21–74a 3.
38 The schema of Aristotle’s argument in this paragraph is:
39 i. e. the property.
40 the subject
41 i, ch. 2.
42 i, ch. 1.
43 Cf. Met. A 980a 28. Met. A I should be compared with this chapter.
TOPICA
Translated by W. A. Pickard-Cambridge
CONTENTS
BOOK I
INTRODUCTORY
CHAPTER
1. Programme of treatise.
2. Uses of treatise.
3. Ideal aimed at.
A. SUBJECTS AND MATERIALS OF DISCUSSIONS
4. Subjects (Problems) and materials (Propositions) classified into four groups according to nature of Predicable concerned.
5. The four Predicables.
6. How far to be treated separately.
7. Different kinds of sameness.
8. Twofold proof of division of Predicables.
9. The ten Categories and their relation to the Predicables.
10. Dialectical Propositions.
11. Dialectical Problems:—Theses.
12. Dialectical Reasoning distinguished from Induction.
B. THE SUPPLY OF ARGUMENTS
13. Four sources of arguments:—
14. (1) How to secure propositions.
15. (2) How to distinguish ambiguous meanings.
16. (3) How to note differences.
17. (4) How to note resemblances.
18. The special uses of the last three processes.
[Books II–VIII omitted.]
TOPICA
(Topics)
BOOK I
1 [100a] Our treatise proposes to find a line of inquiry whereby we shall be able to reason from opinions that are generally accepted about every problem propounded to us, (18) and also shall ourselves, (20) when standing up to an argument, avoid saying anything that will obstruct us. First, then, we must say what reasoning is, and what its varieties are, in order to grasp dialectical reasoning: for this is the object of our search in the treatise before us.
Now reasoning is an argument in which, (25) certain things being laid down, something other than these necessarily comes about through them. (a) It is a ‘demonstration’, when the premisses from which the reasoning starts are true and primary, or are such that our knowledge of them has originally come through premisses which are primary and true: (b) reasoning, (30) on the other hand, is ‘dialectical’, if it reasons from opinions that are generally accepted. [100b] Things are ‘true’ and ‘primary’ which are believed on the strength not of anything else but of themselves: for in regard to the first principles of science it is improper to ask any further for the why and wherefore of them; (18) each of the first principles should command belief in and by itself. (20) On the other hand, those opinions are ‘generally accepted’ which are accepted by every one or by the majority or by the philosophers—i. e. by all, or by the majority, or by the most notable and illustrious of them. Again (c), reasoning is ‘contentious’ if it starts from opinions that seem to be generally accepted, but are not really such, (25) or again if it merely seems to reason from opinions that are or seem to be generally accepted. For not every opinion that seems to be generally accepted actually is generally accepted. For in none of the opinions which we call generally accepted is the illusion entirely on the surface, as happens in the case of the principles of contentious arguments; for the nature of the fallacy in these is obvious immediately, (30) and as a rule even to persons with little power of comprehension. [101a] So then, of the contentious reasonings mentioned, the former really deserves to be called ‘reasoning’ as well, but the other should be called ‘contentious reasoning’, but not ‘reasoning’, since it appears to reason, but does not really do so.
Further (d), besides all the reasonings we have mentioned there are the mis-reasonings that start from the premisses peculiar to the special sciences, (5) as happens (for example) in the case of geometry and her sister sciences. For this form of reasoning appears to differ from the reasonings mentioned above; the man who draws a false figure reasons from things that are neither true and primary, nor yet generally accepted. (10) For he does not fall within the definition; he does not assume opinions that are rece
ived either by every one or by the majority or by philosophers—that is to say, by all, or by most, or by the most illustrious of them—but he conducts his reasoning upon assumptions which, though appropriate to the science in question, are not true; for he effects his mis-reasoning either by describing the semicircles wrongly or by drawing certain lines in a way in which they could not be drawn. (15)
The foregoing must stand for an outline survey of the species of reasoning. In general, in regard both to all that we have already discussed and to those which we shall discuss later, (20) we may remark that that amount of distinction between them may serve, because it is not our purpose to give the exact definition of any of them; we merely want to describe them in outline; we consider it quite enough from the point of view of the line of inquiry before us to be able to recognize each of them in some sort of way.
2 Next in order after the foregoing, we must say for how many and for what purposes the treatise is useful. (25) They are three—intellectual training, casual encounters, and the philosophical sciences. That it is useful as a training is obvious on the face of it. The possession of a plan of inquiry will enable us more easily to argue about the subject proposed. (30) For purposes of casual encounters, it is useful because when we have counted up the opinions held by most people, we shall meet them on the ground not of other people’s convictions but of their own, while we shift the ground of any argument that they appear to us to state unsoundly. For the study of the philosophical sciences it is useful, because the ability to raise searching difficulties on both sides of a subject will make us detect more easily the truth and error about the several points that arise. (35) It has a further use in relation to the ultimate bases of the principles used in the several sciences. For it is impossible to discuss them at all from the principles proper to the particular science in hand, seeing that the principles are the prius of everything else: it is through the opinions generally held on the particular points that these have to be discussed, and this task belongs properly, or most appropriately, to dialectic: for dialectic is a process of criticism wherein lies the path to the principles of all inquiries. [101b]
3 We shall be in perfect possession of the way to proceed when we are in a position like that which we occupy in regard to rhetoric and medicine and faculties of that kind: this means the doing of that which we choose with the materials that are available. (5) For it is not every method that the rhetorician will employ to persuade, or the doctor to heal: still, if he omits none of the available means, (10) we shall say that his grasp of the science is adequate.
4 First, then, we must see of what parts our inquiry consists. Now if we were to grasp (a) with reference to how many, and what kind of, things arguments take place, and with what materials they start, and (b) how we are to become well supplied with these, we should have sufficiently won our goal. Now the materials with which arguments start are equal in number, and are identical, (15) with the subjects on which reasonings take place. For arguments start with ‘propositions’, while the subjects on which reasonings take place are ‘problems’. Now every proposition and every problem indicates either a genus or a peculiarity or an accident—for the differentia too, applying as it does to a class (or genus), should be ranked together with the genus. Since, however, of what is peculiar to anything part signifies its essence, (20) while part does not, let us divide the ‘peculiar’ into both the aforesaid parts, and call that part which indicates the essence a ‘definition’, while of the remainder let us adopt the terminology which is generally current about these things, and speak of it as a ‘property’. What we have said, then, makes it clear that according to our present division, the elements turn out to be four, all told, (25) namely either property or definition or genus or accident. Do not let any one suppose us to mean that each of these enunciated by itself constitutes a proposition or problem, but only that it is from these that both problems and propositions are formed. The difference between a problem and a proposition is a difference in the turn of the phrase. (30) For if it be put in this way, ‘ “An animal that walks on two feet” is the definition of man, is it not?’ or ‘ “Animal” is the genus of man, is it not?’ the result is a proposition: but if thus, ‘Is “an animal that walks on two feet” a definition of man or no?’ [or ‘Is “animal” his genus or no?’] the result is a problem. Similarly too in other cases. Naturally, then, problems and propositions are equal in number: for out of every proposition you will make a problem if you change the turn of the phrase. (35)
5 We must now say what are ‘definition’, ‘property’, ‘genus’, and ‘accident’. A ‘definition’ is a phrase signifying a thing’s essence. It is rendered in the form either of a phrase in lieu of a term, or of a phrase in lieu of another phrase; for it is sometimes possible to define the meaning of a phrase as well. [102a] People whose rendering consists of a term only, try it as they may, clearly do not render the definition of the thing in question, because a definition is always a phrase of a certain kind. One may, however, use the word ‘definitory’ also of such a remark as ‘The “becoming” is “beautiful”,’ (5) and likewise also of the question, ‘Are sensation and knowledge the same or different?’, for argument about definitions is mostly concerned with questions of sameness and difference. In a word we may call ‘definitory’ everything that falls under the same branch of inquiry as definitions; and that all the above-mentioned examples are of this character is clear on the face of them. (10) For if we are able to argue that two things are the same or are different, we shall be well supplied by the same turn of argument with lines of attack upon their definitions as well: for when we have shown that they are not the same we shall have demolished the definition. Observe, please, that the converse of this last statement does not hold: for to show that they are the same is not enough to establish a definition. (15) To show, however, that they are not the same is enough of itself to overthrow it.
A ‘property’ is a predicate which does not indicate the essence of a thing, but yet belongs to that thing alone, and is predicated convertibly of it. Thus it is a property of man to be capable of learning grammar: for if A be a man, then he is capable of learning grammar, (20) and if he be capable of learning grammar, he is a man. For no one calls anything a ‘property’ which may possibly belong to something else, e. g. ‘sleep’ in the case of man, even though at a certain time it may happen to belong to him alone. That is to say, if any such thing were actually to be called a property, it will be called not a ‘property’ absolutely, (25) but a ‘temporary’ or a ‘relative’ property: for ‘being on the right hand side’ is a temporary property, while ‘two-footed’ is in point of fact ascribed as a property in certain relations; e. g. it is a property of man relatively to a horse and a dog. That nothing which may belong to anything else than A is a convertible predicate of A is clear: for it does not necessarily follow that if something is asleep it is a man. (30)
A ‘genus’ is what is predicated in the category of essence of a number of things exhibiting differences in kind. We should treat as predicates in the category of essence all such things as it would be appropriate to mention in reply to the question, ‘What is the object before you?’; as, (35) for example, in the case of man, if asked that question, it is appropriate to say ‘He is an animal’. The question, ‘Is one thing in the same genus as another or in a different one?’ is also a ‘generic’ question; for a question of that kind as well falls under the same branch of inquiry as the genus: for having argued that ‘animal’ is the genus of man, and likewise also of ox, we shall have argued that they are in the same genus; whereas if we show that it is the genus of the one but not of the other, we shall have argued that these things are not in the same genus. [102b]
An ‘accident’ is (1) something which, though it is none of the foregoing—i. e. neither a definition nor a property nor a genus—yet belongs to the thing: (5) (2) something which may possibly either belong or not belong to any one and the self-same thing, as (e. g.) the ‘sitting posture’ may b
elong or not belong to some self-same thing. Likewise also ‘whiteness’, for there is nothing to prevent the same thing being at one time white, and at another not white. (10) Of the definitions of accident the second is the better: for if he adopts the first, any one is bound, if he is to understand it, to know already what ‘definition’ and ‘genus’ and ‘property’ are, whereas the second is sufficient of itself to tell us the essential meaning of the term in question. (15) To Accident are to be attached also all comparisons of things together, when expressed in language that is drawn in any kind of way from what happens (accidit) to be true of them; such as, for example, the question, ‘Is the honourable or the expedient preferable?’ and ‘Is the life of virtue or the life of self-indulgence the pleasanter?’, and any other problem which may happen to be phrased in terms like these. For in all such cases the question is ‘to which of the two does the predicate in question happen (accidit) to belong more closely?’ It is clear on the face of it that there is nothing to prevent an accident from becoming a temporary or a relative property. (20) Thus the sitting posture is an accident, but will be a temporary property, whenever a man is the only person sitting, while if he be not the only one sitting, it is still a property relatively to those who are not sitting. (25) So then, there is nothing to prevent an accident from becoming both a relative and a temporary property; but a property absolutely it will never be.
6 We must not fail to observe that all remarks made in criticism of a ‘property’ and ‘genus’ and ‘accident’ will be applicable to ‘definitions’ as well. For when we have shown that the attribute in question fails to belong only to the term defined, as we do also in the case of a property, (30) or that the genus rendered in the definition is not the true genus, or that any of the things mentioned in the phrase used does not belong, as would be remarked also in the case of an accident, we shall have demolished the definition; so that, to use the phrase previously employed,1 all the points we have enumerated might in a certain sense be called ‘definitory’. But we must not on this account expect to find a single line of inquiry which will apply universally to them all: for this is not an easy thing to find, (35) and, even were one found, it would be very obscure indeed, and of little service for the treatise before us. Rather, a special plan of inquiry must be laid down for each of the classes we have distinguished, and then, starting from the rules that are appropriate in each case, it will probably be easier to make our way right through the task before us. [103a] So then, as was said before,2 we must outline a division of our subject, and other questions we must relegate each to the particular branch to which it most naturally belongs, speaking of them as ‘definitory’ and ‘generic’ questions. The questions I mean have practically been already assigned to their several branches. (5)
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