Aristotle

by Various Works [lit]

  these things to be the contrary of the term originally used, then

  clearly neither of the definitions rendered later could be the

  definition of the contrary of the term originally defined: and

  therefore the definition originally rendered of the original term

  has not been rightly rendered either. Seeing, moreover, that of

  contraries, the one is sometimes a word forced to denote the privation

  of the other, as (e.g.) inequality is generally held to be the

  privation of equality (for 'unequal' merely describes things that

  are not equal'), it is therefore clear that that contrary whose form

  denotes the privation must of necessity be defined through the

  other; whereas the other cannot then be defined through the one

  whose form denotes the privation; for else we should find that each is

  being interpreted by the other. We must in the case of contrary

  terms keep an eye on this mistake, e.g. supposing any one were to

  define equality as the contrary of inequality: for then he is defining

  it through the term which denotes privation of it. Moreover, a man who

  so defines is bound to use in his definition the very term he is

  defining; and this becomes clear, if for the word we substitute its

  definition. For to say 'inequality' is the same as to say 'privation

  of equality'. Therefore equality so defined will be 'the contrary of

  the privation of equality', so that he would have used the very word

  to be defined. Suppose, however, that neither of the contraries be

  so formed as to denote privation, but yet the definition of it be

  rendered in a manner like the above, e.g. suppose 'good' to be defined

  as 'the contrary of evil', then, since it is clear that 'evil' too

  will be 'the contrary of good' (for the definition of things that

  are contrary in this must be rendered in a like manner), the result

  again is that he uses the very term being defined: for 'good' is

  inherent in the definition of 'evil'. If, then, 'good' be the contrary

  of evil, and evil be nothing other than the 'contrary of good', then

  'good' will be the 'contrary of the contrary of good'. Clearly,

  then, he has used the very word to be defined.

  Moreover, see if in rendering a term formed to denote privation,

  he has failed to render the term of which it is the privation, e.g.

  the state, or contrary, or whatever it may be whose privation it is:

  also if he has omitted to add either any term at all in which the

  privation is naturally formed, or else that in which it is naturally

  formed primarily, e.g. whether in defining 'ignorance' a privation

  he has failed to say that it is the privation of 'knowledge'; or has

  failed to add in what it is naturally formed, or, though he has

  added this, has failed to render the thing in which it is primarily

  formed, placing it (e.g.) in 'man' or in 'the soul', and not in the

  'reasoning faculty': for if in any of these respects he fails, he

  has made a mistake. Likewise, also, if he has failed to say that

  'blindness' is the 'privation of sight in an eye': for a proper

  rendering of its essence must state both of what it is the privation

  and what it is that is deprived.

  Examine further whether he has defined by the expression 'a

  privation' a term that is not used to denote a privation: thus a

  mistake of this sort also would be generally thought to be incurred in

  the case of 'error' by any one who is not using it as a merely

  negative term. For what is generally thought to be in error is not

  that which has no knowledge, but rather that which has been

  deceived, and for this reason we do not talk of inanimate things or of

  children as 'erring'. 'Error', then, is not used to denote a mere

  privation of knowledge.

  10

  Moreover, see whether the like inflexions in the definition apply to

  the like inflexions of the term; e.g. if 'beneficial' means

  'productive of health', does 'beneficially' mean productively of

  health' and a 'benefactor' a 'producer of health'?

  Look too and see whether the definition given will apply to the Idea

  as well. For in some cases it will not do so; e.g. in the Platonic

  definition where he adds the word 'mortal' in his definitions of

  living creatures: for the Idea (e.g. the absolute Man) is not

  mortal, so that the definition will not fit the Idea. So always

  wherever the words 'capable of acting on' or 'capable of being acted

  upon' are added, the definition and the Idea are absolutely bound to

  be discrepant: for those who assert the existence of Ideas hold that

  they are incapable of being acted upon, or of motion. In dealing

  with these people even arguments of this kind are useful.

  Further, see if he has rendered a single common definition of

  terms that are used ambiguously. For terms whose definition

  corresponding their common name is one and the same, are synonymous;

  if, then, the definition applies in a like manner to the whole range

  of the ambiguous term, it is not true of any one of the objects

  described by the term. This is, moreover, what happens to Dionysius'

  definition of 'life' when stated as 'a movement of a creature

  sustained by nutriment, congenitally present with it': for this is

  found in plants as much as in animals, whereas 'life' is generally

  understood to mean not one kind of thing only, but to be one thing

  in animals and another in plants. It is possible to hold the view that

  life is a synonymous term and is always used to describe one thing

  only, and therefore to render the definition in this way on purpose:

  or it may quite well happen that a man may see the ambiguous character

  of the word, and wish to render the definition of the one sense

  only, and yet fail to see that he has rendered a definition common

  to both senses instead of one peculiar to the sense he intends. In

  either case, whichever course he pursues, he is equally at fault.

  Since ambiguous terms sometimes pass unobserved, it is best in

  questioning to treat such terms as though they were synonymous (for

  the definition of the one sense will not apply to the other, so that

  the answerer will be generally thought not to have defined it

  correctly, for to a synonymous term the definition should apply in its

  full range), whereas in answering you should yourself distinguish

  between the senses. Further, as some answerers call 'ambiguous' what

  is really synonymous, whenever the definition rendered fails to

  apply universally, and, vice versa, call synonymous what is really

  ambiguous supposing their definition applies to both senses of the

  term, one should secure a preliminary admission on such points, or

  else prove beforehand that so-and-so is ambiguous or synonymous, as

  the case may be: for people are more ready to agree when they do not

  foresee what the consequence will be. If, however, no admission has

  been made, and the man asserts that what is really synonymous is

  ambiguous because the definition he has rendered will not apply to the

  second sense as well, see if the definition of this second meaning

  applies also to the other meanings: for if so, this meaning must

 
clearly be synonymous with those others. Otherwise, there will be more

  than one definition of those other meanings, for there are

  applicable to them two distinct definitions in explanation of the

  term, viz. the one previously rendered and also the later one.

  Again, if any one were to define a term used in several senses, and,

  finding that his definition does not apply to them all, were to

  contend not that the term is ambiguous, but that even the term does

  not properly apply to all those senses, just because his definition

  will not do so either, then one may retort to such a man that though

  in some things one must not use the language of the people, yet in a

  question of terminology one is bound to employ the received and

  traditional usage and not to upset matters of that sort.

  11

  Suppose now that a definition has been rendered of some complex

  term, take away the definition of one of the elements in the

  complex, and see if also the rest of the definition defines the rest

  of it: if not, it is clear that neither does the whole definition

  define the whole complex. Suppose, e.g. that some one has defined a

  'finite straight line' as 'the limit of a finite plane, such that

  its centre is in a line with its extremes'; if now the definition of a

  finite line' be the 'limit of a finite plane', the rest (viz. 'such

  that its centre is in a line with its extremes') ought to be a

  definition of straight'. But an infinite straight line has neither

  centre nor extremes and yet is straight so that this remainder does

  not define the remainder of the term.

  Moreover, if the term defined be a compound notion, see if the

  definition rendered be equimembral with the term defined. A definition

  is said to be equimembral with the term defined when the number of the

  elements compounded in the latter is the same as the number of nouns

  and verbs in the definition. For the exchange in such cases is bound

  to be merely one of term for term, in the case of some if not of

  all, seeing that there are no more terms used now than formerly;

  whereas in a definition terms ought to be rendered by phrases, if

  possible in every case, or if not, in the majority. For at that

  rate, simple objects too could be defined by merely calling them by

  a different name, e.g. 'cloak' instead of 'doublet'.

  The mistake is even worse, if actually a less well known term be

  substituted, e.g. 'pellucid mortal' for 'white man': for it is no

  definition, and moreover is less intelligible when put in that form.

  Look and see also whether, in the exchange of words, the sense fails

  still to be the same. Take, for instance, the explanation of

  'speculative knowledge' as 'speculative conception': for conception is

  not the same as knowledge-as it certainly ought to be if the whole

  is to be the same too: for though the word 'speculative' is common

  to both expressions, yet the remainder is different.

  Moreover, see if in replacing one of the terms by something else

  he has exchanged the genus and not the differentia, as in the

  example just given: for 'speculative' is a less familiar term than

  knowledge; for the one is the genus and the other the differentia, and

  the genus is always the most familiar term of all; so that it is not

  this, but the differentia, that ought to have been changed, seeing

  that it is the less familiar. It might be held that this criticism

  is ridiculous: because there is no reason why the most familiar term

  should not describe the differentia, and not the genus; in which case,

  clearly, the term to be altered would also be that denoting the

  genus and not the differentia. If, however, a man is substituting

  for a term not merely another term but a phrase, clearly it is of

  the differentia rather than of the genus that a definition should be

  rendered, seeing that the object of rendering the definition is to

  make the subject familiar; for the differentia is less familiar than

  the genus.

  If he has rendered the definition of the differentia, see whether

  the definition rendered is common to it and something else as well:

  e.g. whenever he says that an odd number is a 'number with a

  middle', further definition is required of how it has a middle: for

  the word 'number' is common to both expressions, and it is the word

  'odd' for which the phrase has been substituted. Now both a line and a

  body have a middle, yet they are not 'odd'; so that this could not

  be a definition of 'odd'. If, on the other hand, the phrase 'with a

  middle' be used in several senses, the sense here intended requires to

  be defined. So that this will either discredit the definition or prove

  that it is no definition at all.

  12

  Again, see if the term of which he renders the definition is a

  reality, whereas what is contained in the definition is not, e.g.

  Suppose 'white' to be defined as 'colour mingled with fire': for

  what is bodiless cannot be mingled with body, so that 'colour'

  'mingled with fire' could not exist, whereas 'white' does exist.

  Moreover, those who in the case of relative terms do not distinguish

  to what the object is related, but have described it only so as to

  include it among too large a number of things, are wrong either wholly

  or in part; e.g. suppose some one to have defined 'medicine' as a

  science of Reality'. For if medicine be not a science of anything that

  is real, the definition is clearly altogether false; while if it be

  a science of some real thing, but not of another, it is partly

  false; for it ought to hold of all reality, if it is said to be of

  Reality essentially and not accidentally: as is the case with other

  relative terms: for every object of knowledge is a term relative to

  knowledge: likewise, also, with other relative terms, inasmuch as

  all such are convertible. Moreover, if the right way to render account

  of a thing be to render it as it is not in itself but accidentally,

  then each and every relative term would be used in relation not to one

  thing but to a number of things. For there is no reason why the same

  thing should not be both real and white and good, so that it would

  be a correct rendering to render the object in relation to any one

  whatsoever of these, if to render what it is accidentally be a correct

  way to render it. It is, moreover, impossible that a definition of

  this sort should be peculiar to the term rendered: for not only but

  the majority of the other sciences too, have for their object some

  real thing, so that each will be a science of reality. Clearly,

  then, such a definition does not define any science at all; for a

  definition ought to be peculiar to its own term, not general.

  Sometimes, again, people define not the thing but only the thing

  in a good or perfect condition. Such is the definition of a

  rhetorician as 'one who can always see what will persuade in the given

  circumstances, and omit nothing'; or of a thief, as 'one who pilfers

  in secret': for clearly, if they each do this, then the one will be

  a good rhetorician, and the other a good thief: whereas it is not

 
; the actual pilfering in secret, but the wish to do it, that

  constitutes the thief.

  Again, see if he has rendered what is desirable for its own sake

  as desirable for what it produces or does, or as in any way

  desirable because of something else, e.g. by saying that justice is

  'what preserves the laws' or that wisdom is 'what produces happiness';

  for what produces or preserves something else is one of the things

  desirable for something else. It might be said that it is possible for

  what is desirable in itself to be desirable for something else as

  well: but still to define what is desirable in itself in such a way is

  none the less wrong: for the essence contains par excellence what is

  best in anything, and it is better for a thing to be desirable in

  itself than to be desirable for something else, so that this is rather

  what the definition too ought to have indicated.

  13

  See also whether in defining anything a man has defined it as an

  'A and B', or as a 'product of A and B' or as an 'A+B'. If he

  defines it as and B', the definition will be true of both and yet of

  neither of them; suppose, e.g. justice to be defined as 'temperance

  and courage.' For if of two persons each has one of the two only, both

  and yet neither will be just: for both together have justice, and

  yet each singly fails to have it. Even if the situation here described

  does not so far appear very absurd because of the occurrence of this

  kind of thing in other cases also (for it is quite possible for two

  men to have a mina between them, though neither of them has it by

  himself), yet least that they should have contrary attributes surely

  seems quite absurd; and yet this will follow if the one be temperate

  and yet a coward, and the other, though brave, be a profligate; for

  then both will exhibit both justice and injustice: for if justice be

  temperance and bravery, then injustice will be cowardice and

  profligacy. In general, too, all the ways of showing that the whole is

  not the same as the sum of its parts are useful in meeting the type

  just described; for a man who defines in this way seems to assert that