Various Works

  not for their being, but for their well-being. Such, e.g. is sight,

  which, since it lives in air or water, or generally in what is

  pellucid, it must have in order to see, and taste because of what is

  pleasant or painful to it, in order that it may perceive these

  qualities in its nutriment and so may desire to be set in motion,

  and hearing that it may have communication made to it, and a tongue

  that it may communicate with its fellows.

  THE END

  .

  350 BC

  TOPICS

  by Aristotle

  translated by W. A. Pickard-Cambridge

  Book I

  1

  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, and also shall ourselves, 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, 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, on the other hand, is

  'dialectical', if it reasons from opinions that are generally

  accepted. 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; each of the first principles should

  command belief in and by itself. 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, 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, and as a rule even

  to persons with little power of comprehension. 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, 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. For he does

  not fall within the definition; he does not assume opinions that are

  received 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.

  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, 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. 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. 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. 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.

  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. 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, 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 (h) 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, 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, 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, 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. 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.

  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. 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"',

  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. 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. 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, 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, 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.

  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, 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.

  An 'accident' is (i) 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: (something which may possibly either belong or

  not belong to any one and the self-same thing, as (e.g.) the

  'sitting posture' may belong 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. 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. 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 relative property.

  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. 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, or that the genus rendered in the definition

  is not the true genus, or that any of the things mentioned in the

  p
hrase 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,' 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, 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. So then, as was said before,' 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.

  7

  First of all we must define the number of senses borne by the term

  'Sameness'. Sameness would be generally regarded as falling, roughly

  speaking, into three divisions. We generally apply the term

  numerically or specifically or generically-numerically in cases

  where there is more than one name but only one thing, e.g. 'doublet'

  and 'cloak'; specifically, where there is more than one thing, but

  they present no differences in respect of their species, as one man

  and another, or one horse and another: for things like this that

  fall under the same species are said to be 'specifically the same'.

  Similarly, too, those things are called generically the same which

  fall under the same genus, such as a horse and a man. It might

  appear that the sense in which water from the same spring is called

  'the same water' is somehow different and unlike the senses

  mentioned above: but really such a case as this ought to be ranked