Aristotle

by Various Works [lit]

  to their truth, but for dialectic only with an eye to general opinion.

  All propositions should be taken in their most universal form; then,

  the one should be made into many. E.g. 'The knowledge of opposites

  is the same'; next, 'The knowledge of contraries is the same', and

  that 'of relative terms'. In the same way these two should again be

  divided, as long as division is possible, e.g. the knowledge of

  'good and evil', of 'white and black', or 'cold and hot'. Likewise

  also in other cases.

  15

  On the formation, then, of propositions, the above remarks are

  enough. As regards the number of senses a term bears, we must not only

  treat of those terms which bear different senses, but we must also try

  to render their definitions; e.g. we must not merely say that

  justice and courage are called 'good' in one sense, and that what

  conduces to vigour and what conduces to health are called so in

  another, but also that the former are so called because of a certain

  intrinsic quality they themselves have, the latter because they are

  productive of a certain result and not because of any intrinsic

  quality in themselves. Similarly also in other cases.

  Whether a term bears a number of specific meanings or one only,

  may be considered by the following means. First, look and see if its

  contrary bears a number of meanings, whether the discrepancy between

  them be one of kind or one of names. For in some cases a difference is

  at once displayed even in the names; e.g. the contrary of 'sharp' in

  the case of a note is 'flat', while in the case of a solid edge it

  is 'dull'. Clearly, then, the contrary of 'sharp' bears several

  meanings, and if so, also does 'sharp'; for corresponding to each of

  the former terms the meaning of its contrary will be different. For

  'sharp' will not be the same when contrary to 'dull' and to 'flat',

  though 'sharp' is the contrary of each. Again Barhu ('flat',

  'heavy') in the case of a note has 'sharp' as its contrary, but in the

  case of a solid mass 'light', so that Barhu is used with a number of

  meanings, inasmuch as its contrary also is so used. Likewise, also,

  'fine' as applied to a picture has 'ugly' as its contrary, but, as

  applied to a house, 'ramshackle'; so that 'fine' is an ambiguous term.

  In some cases there is no discrepancy of any sort in the names used,

  but a difference of kind between the meanings is at once obvious: e.g.

  in the case of 'clear' and 'obscure': for sound is called 'clear'

  and 'obscure', just as 'colour' is too. As regards the names, then,

  there is no discrepancy, but the difference in kind between the

  meanings is at once obvious: for colour is not called 'clear' in a

  like sense to sound. This is plain also through sensation: for of

  things that are the same in kind we have the same sensation, whereas

  we do not judge clearness by the same sensation in the case of sound

  and of colour, but in the latter case we judge by sight, in the former

  by hearing. Likewise also with 'sharp' and 'dull' in regard to

  flavours and solid edges: here in the latter case we judge by touch,

  but in the former by taste. For here again there is no discrepancy

  in the names used, in the case either of the original terms or of

  their contraries: for the contrary also of sharp in either sense is

  'dull'.

  Moreover, see if one sense of a term has a contrary, while another

  has absolutely none; e.g. the pleasure of drinking has a contrary in

  the pain of thirst, whereas the pleasure of seeing that the diagonal

  is incommensurate with the side has none, so that 'pleasure' is used

  in more than one sense. To 'love' also, used of the frame of mind, has

  to 'hate' as its contrary, while as used of the physical activity

  (kissing) it has none: clearly, therefore, to 'love' is an ambiguous

  term. Further, see in regard to their intermediates, if some

  meanings and their contraries have an intermediate, others have

  none, or if both have one but not the same one, e.g. 'clear' and

  'obscure' in the case of colours have 'grey' as an intermediate,

  whereas in the case of sound they have none, or, if they have, it is

  'harsh', as some people say that a harsh sound is intermediate.

  'Clear', then, is an ambiguous term, and likewise also 'obscure'. See,

  moreover, if some of them have more than one intermediate, while

  others have but one, as is the case with 'clear' and 'obscure', for in

  the case of colours there are numbers of intermediates, whereas in

  regard to sound there is but one, viz. 'harsh'.

  Again, in the case of the contradictory opposite, look and see if it

  bears more than one meaning. For if this bears more than one

  meaning, then the opposite of it also will be used in more than one

  meaning; e.g. 'to fail to see' a phrase with more than one meaning,

  viz. (1) to fail to possess the power of sight, (2) to fail to put

  that power to active use. But if this has more than one meaning, it

  follows necessarily that 'to see' also has more than one meaning:

  for there will be an opposite to each sense of 'to fail to see';

  e.g. the opposite of 'not to possess the power of sight' is to possess

  it, while of 'not to put the power of sight to active use', the

  opposite is to put it to active use.

  Moreover, examine the case of terms that denote the privation or

  presence of a certain state: for if the one term bears more than one

  meaning, then so will the remaining term: e.g. if 'to have sense' be

  used with more than one meaning, as applied to the soul and to the

  body, then 'to be wanting in sense' too will be used with more than

  one meaning, as applied to the soul and to the body. That the

  opposition between the terms now in question depends upon the

  privation or presence of a certain state is clear, since animals

  naturally possess each kind of 'sense', both as applied to the soul

  and as applied to the body.

  Moreover, examine the inflected forms. For if 'justly' has more than

  one meaning, then 'just', also, will be used with more than one

  meaning; for there will be a meaning of 'just' to each of the meanings

  of 'justly'; e.g. if the word 'justly' be used of judging according to

  one's own opinion, and also of judging as one ought, then 'just'

  also will be used in like manner. In the same way also, if 'healthy'

  has more than one meaning, then 'healthily' also will be used with

  more than one meaning: e.g. if 'healthy' describes both what

  produces health and what preserves health and what betokens health,

  then 'healthily' also will be used to mean 'in such a way as to

  produce' or 'preserve' or 'betoken' health. Likewise also in other

  cases, whenever the original term bears more than one meaning, the

  inflexion also that is formed from it will be used with more than

  one meaning, and vice versa.

  Look also at the classes of the predicates signified by the term,

  and see if they are the same in all cases. For if they are not the

  same, then clearly the term is ambiguous: e.g. 'good' in the case of

  food means 'productive of pleasure', and in the case of medicine

>   'productive of health', whereas as applied to the soul it means to

  be of a certain quality, e.g. temperate or courageous or just: and

  likewise also, as applied to 'man'. Sometimes it signifies what

  happens at a certain time, as (e.g.) the good that happens at the

  right time: for what happens at the right time is called good. Often

  it signifies what is of certain quantity, e.g. as applied to the

  proper amount: for the proper amount too is called good. So then the

  term 'good' is ambiguous. In the same way also 'clear', as applied

  to a body, signifies a colour, but in regard to a note it denotes what

  is 'easy to hear'. 'Sharp', too, is in a closely similar case: for the

  same term does not bear the same meaning in all its applications:

  for a sharp note is a swift note, as the mathematical theorists of

  harmony tell us, whereas a sharp (acute) angle is one that is less

  than a right angle, while a sharp dagger is one containing a sharp

  angle (point).

  Look also at the genera of the objects denoted by the same term, and

  see if they are different without being subaltern, as (e.g.) 'donkey',

  which denotes both the animal and the engine. For the definition of

  them that corresponds to the name is different: for the one will be

  declared to be an animal of a certain kind, and the other to be an

  engine of a certain kind. If, however, the genera be subaltern,

  there is no necessity for the definitions to be different. Thus (e.g.)

  'animal' is the genus of 'raven', and so is 'bird'. Whenever therefore

  we say that the raven is a bird, we also say that it is a certain kind

  of animal, so that both the genera are predicated of it. Likewise also

  whenever we call the raven a 'flying biped animal', we declare it to

  be a bird: in this way, then, as well, both the genera are

  predicated of raven, and also their definition. But in the case of

  genera that are not subaltern this does not happen, for whenever we

  call a thing an 'engine', we do not call it an animal, nor vice versa.

  Look also and see not only if the genera of the term before you

  are different without being subaltern, but also in the case of its

  contrary: for if its contrary bears several senses, clearly the term

  before you does so as well.

  It is useful also to look at the definition that arises from the use

  of the term in combination, e.g. of a 'clear (lit. white) body' of a

  'clear note'. For then if what is peculiar in each case be abstracted,

  the same expression ought to remain over. This does not happen in

  the case of ambiguous terms, e.g. in the cases just mentioned. For the

  former will be body possessing such and such a colour', while the

  latter will be 'a note easy to hear'. Abstract, then, 'a body 'and'

  a note', and the remainder in each case is not the same. It should,

  however, have been had the meaning of 'clear' in each case been

  synonymous.

  Often in the actual definitions as well ambiguity creeps in

  unawares, and for this reason the definitions also should be examined.

  If (e.g.) any one describes what betokens and what produces health

  as 'related commensurably to health', we must not desist but go on

  to examine in what sense he has used the term 'commensurably' in

  each case, e.g. if in the latter case it means that 'it is of the

  right amount to produce health', whereas in the for it means that

  'it is such as to betoken what kind of state prevails'.

  Moreover, see if the terms cannot be compared as 'more or less' or

  as 'in like manner', as is the case (e.g.) with a 'clear' (lit. white)

  sound and a 'clear' garment, and a 'sharp' flavour and a 'sharp' note.

  For neither are these things said to be clear or sharp 'in a like

  degree', nor yet is the one said to be clearer or sharper than the

  other. 'Clear', then, and 'sharp' are ambiguous. For synonyms are

  always comparable; for they will always be used either in like manner,

  or else in a greater degree in one case.

  Now since of genera that are different without being subaltern the

  differentiae also are different in kind, e.g. those of 'animal' and

  'knowledge' (for the differentiae of these are different), look and

  see if the meanings comprised under the same term are differentiae

  of genera that are different without being subaltern, as e.g.

  'sharp' is of a 'note' and a 'solid'. For being 'sharp' differentiates

  note from note, and likewise also one solid from another. 'Sharp',

  then, is an ambiguous term: for it forms differentiae of genera that

  are different without being subaltern.

  Again, see if the actual meanings included under the same term

  themselves have different differentiae, e.g. 'colour' in bodies and

  'colour' in tunes: for the differentiae of 'colour' in bodies are

  'sight-piercing' and 'sight compressing', whereas 'colour' in melodies

  has not the same differentiae. Colour, then, is an ambiguous term; for

  things that are the same have the same differentiae.

  Moreover, since the species is never the differentia of anything,

  look and see if one of the meanings included under the same term be

  a species and another a differentia, as (e.g.) clear' (lit. white)

  as applied to a body is a species of colour, whereas in the case of

  a note it is a differentia; for one note is differentiated from

  another by being 'clear'.

  16

  The presence, then, of a number of meanings in a term may be

  investigated by these and like means. The differences which things

  present to each other should be examined within the same genera,

  e.g. 'Wherein does justice differ from courage, and wisdom from

  temperance?'-for all these belong to the same genus; and also from one

  genus to another, provided they be not very much too far apart, e.g.

  'Wherein does sensation differ from knowledge?: for in the case of

  genera that are very far apart, the differences are entirely obvious.

  17

  Likeness should be studied, first, in the case of things belonging

  to different genera, the formulae being 'A:B = C:D' (e.g. as knowledge

  stands to the object of knowledge, so is sensation related to the

  object of sensation), and 'As A is in B, so is C in D' (e.g. as

  sight is in the eye, so is reason in the soul, and as is a calm in the

  sea, so is windlessness in the air). Practice is more especially

  needed in regard to terms that are far apart; for in the case of the

  rest, we shall be more easily able to see in one glance the points

  of likeness. We should also look at things which belong to the same

  genus, to see if any identical attribute belongs to them all, e.g.

  to a man and a horse and a dog; for in so far as they have any

  identical attribute, in so far they are alike.

  18

  It is useful to have examined the number of meanings of a term

  both for clearness' sake (for a man is more likely to know what it

  is he asserts, if it bas been made clear to him how many meanings it

  may have), and also with a view to ensuring that our reasonings

  shall be in accordance with the actual facts and not addressed

  merely to the term used. For as long as it is not clear in how m
any

  senses a term is used, it is possible that the answerer and the

  questioner are not directing their minds upon the same thing:

  whereas when once it has been made clear how many meanings there

  are, and also upon which of them the former directs his mind when he

  makes his assertion, the questioner would then look ridiculous if he

  failed to address his argument to this. It helps us also both to avoid

  being misled and to mislead by false reasoning: for if we know the

  number of meanings of a term, we shall certainly never be misled by

  false reasoning, but shall know if the questioner fails to address his

  argument to the same point; and when we ourselves put the questions we

  shall be able to mislead him, if our answerer happens not to know

  the number of meanings of our terms. This, however, is not possible in

  all cases, but only when of the many senses some are true and others

  are false. This manner of argument, however, does not belong

  properly to dialectic; dialecticians should therefore by all means

  beware of this kind of verbal discussion, unless any one is absolutely

  unable to discuss the subject before him in any other way.

  The discovery of the differences of things helps us both in

  reasonings about sameness and difference, and also in recognizing what

  any particular thing is. That it helps us in reasoning about

  sameness and difference is clear: for when we have discovered a

  difference of any kind whatever between the objects before us, we

  shall already have shown that they are not the same: while it helps us

  in recognizing what a thing is, because we usually distinguish the

  expression that is proper to the essence of each particular thing by

  means of the differentiae that are proper to it.

  The examination of likeness is useful with a view both to

  inductive arguments and to hypothetical reasonings, and also with a

  view to the rendering of definitions. It is useful for inductive

  arguments, because it is by means of an induction of individuals in