Aristotle
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 as substitute.[341] 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.[342]
[Footnote 341: Topic. VI. xiv. p. 151, b. 3-11. [Greek: o(/soi t'
a)saphei=s tô=n o(rismô=n, sundiorthô/santa kai\ suschêmati/santa
pro\s to\ dêlou=n ti kai\ e)/chein e)pichei/rêma, ou(/tôs
e)piskopei=n; a)nagkai=on ga\r tô=| a)pokrinome/nô| ê)\ de/chesthai
to\ e)klambano/menon u(po\ tou= e)rôtô=ntos, ê)\ au)to\n diasaphê=sai
ti/ pote tugcha/nei to\ dêlou/menon u(po\ tou= lo/gou.]]
[Footnote 342: Ibid. b. 12-17.]
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.[343]
[Footnote 343: Ibid. b. 18-23. [Greek: a)na/gkê ga\r, ô(/sper pro\s
para/deigma theô/menon, to/ t' e)llei=pon ô(=n prosê=ken e)/chein
to\n o(rismo\n kai\ to\ proskei/menon perie/rgôs kathora=n, ô(/ste
ma=llon e)picheirêma/tôn eu)porei=n.]]
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.[344]
[Footnote 344: Ibid. VII. i. p. 151, b. 28: [Greek: po/teron de\
tau)to\n ê)\ e(/teron kata\ to\n kuriô/taton tô=n r(êthe/ntôn peri\
tau)tou= tro/pôn (e)le/geto de\ kuriô/tata tau)to\n to\ tô=|
a)rithmô=| e(/n)] &c.]
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.[345] If there be any predicate applied to courage in the
superlative degree, the same predicate will also be applied to
justice in the superlative degree.[346] 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.[347]
[Footnote 345: Ibid. p. 152, a. 2.]
[Footnote 346: Topic. VII. p. 152, a. 5-30: [Greek: skopei=n de\ kai\
ô(=n tha/teron ma/lista le/getai o(tiou=n, ei) kai\ tha/teron tô=n
au)tôn tou/tôn kata\ to\ au)to\ ma/lista le/getai, katha/per
Xenokra/tês to\n eu)dai/mona bi/on kai\ to\n spoudai=on a)podei/knusi
to\n au)to/n, e)peidê\ pa/ntôn tô=n bi/ôn ai(retô/tatos o( spoudai=os
kai\ o( eu)dai/môn; e(\n ga\r to\ ai(retô/taton kai\ to\ me/giston;]
&c.
Aristotle remarks that Xenokrates here carried his inference too far:
that the application of the same superlative predicate to A and B
affords indeed a presumption that they are _Idem numero_, but not a
conclusive proof thereof; that the predicate might be applied in like
manner, if B were a species comprised in A as genus.
Xenokrates made the mistake of drawing an affirmative conclusion from
syllogistic premisses in the Second figure.]
[Footnote 347: Topic. VII. i. p. 152, a. 31-b. 16.]
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;[348] whether the identity is not merely _specie_
or _genere_; finally, whether the one can exist without the
other.[349]
[Footnote 348: Ibid. b. 17-24. Aristotle illustrates this _locus_ as
follows:--Some say that to be _void_, and to be _full of air_, are
the same. But suppose the air to be drawn away; then the place will
no longer be full of air, yet it will still be void, even more than
it was before. One of the two terms declared to be identical is thus
withdrawn, while the other remains. Accordingly, the two are not
really identical. This illustration fits better to the principle laid
down, b. 34: [Greek: ei) du/naton tha/teron a)/neu thate/rou ei)=nai;
ou) ga\r a)\n ei)/ê tau)to/n.]]
[Footnote 349: Ibid. b. 25-35.]
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.[350]
[Footnote 350: Ibid. ii. p. 152, b. 36-p. 158, a. 5. [Greek:
a(/pantes oi( pro\s tau)to\n a)naskeuastikoi\ to/poi kai\ pro\s
o(/ron chrê/simoi--tô=n de\ kataskeuastikô=n to/pôn ou)dei\s
chrê/simos pro\s o(/ron;] &c.]
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 way 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.[351]
[Footnote 351: Topic. VII. iii. p. 153, a. 6-22. Compare Analyt.
Post. II. iii.-x., where the theory of Scientific Definition is
elaborately worked out; supra, Vol. I. ch. viii. pp. 346-353.]
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.[352] 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.[353]
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.[354]
[Footnote 352: Ibid. a. 28: [Greek: ei) ga\r o( a)ntikei/menos tou=
a)ntikeime/nou, kai\ to\n ei)rême/nou tou= prokeime/nou a)na/gkê
ei)=nai (o(/ron).]]
[Footnote 353: Ibid. b. 14: [Greek: katho/lou d' ei)pei=n, e)pei\ o(
o(rismo/s e)stin e)k ge/nous kai\ diaphorô=n, a)\n o( tou= e)nanti/ou
o(rismo\s phanero\s ê)=|, kai\ o( tou= prokeime/nou o(rismo\s
phanero\s e)/stai.]]
[Footnote 354: Topic. VII. iii. p. 153, b. 25-p. 154, a. 11: [Greek:
e)/ti e)k tô=n ptô/seôn kai\ tô=n sustoi/chôn; a)na/gkê a)kolouthei=n
ta\ ge/nê toi=s ge/nesin kai\ tou\s o(/rous toi=s o(/rois.--e(no\s
ou)=n o(poiouou=n tô=n ei)rême/nôn o(molêthe/ntos, a)na/gkê ki\ ta\
loipa\ o(mologei=sthai.--kai\ e)k tô=n o(moi/ôs e)cho/ntôn pro\s
a)/llêla--o(moi/ôs ga\r e(/kaston tô=n ei)rême/nôn pro\s to\
oi)kei=on te/los e)/chei.]]
These _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.[355]
[Footnote 355: Topic. VII. iv. p. 154, a. 12-22.]
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.[356] 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.[357]
[Footnote 356: Topic. VII. v. p. 154, a. 23, seq. [Greek: kai\ ga\r
i)dei=n au)to\n kai\ labei=n para\ tô=n e)rôtôme/nôn ta\s toiau/tas
prota/seis ou)k eu)pete/s], &c.]
[Footnote 357: Ibid. a. 32-b. 12.]