Aristotle
itself (_e.g._, _bonum_) and not included in any superior genus, then
the like will be true respecting the species itself: it will not be
included in any genus; and the predicate of the thesis will not be a
true genus. _Bonum_ and _malum_ are not included in any common
superior genus; each is a genus _per se_.[169] Or suppose that the
subject (species) of the thesis, and the predicate (genus) of the
thesis, have both of them contraries; but that in the one there is an
intermediate between the two contraries, and in the other, not. This
shows that the predicate cannot be the true genus of the species;
for, wherever there is an intermediate between the two contraries of
the species, there also is an intermediate between the two contraries
of the genus; and _vice versâ_.[170] If there be an intermediate
between the two contraries of the species, and also an intermediate
between the two contraries of the genus, you will examine whether
both intermediates are of like nature, designated by analogous terms.
If it be not so (if, _e.g._, the one intermediate is designated by a
positive term, and the other only by a negative term), you will have
ground for contending against the thesis, that the predicate
enunciated therein is not the true genus of the subject. At any rate,
this is a probable ([Greek: e)/ndoxon]) dialectical argument--to
insist upon analogy between the two intermediates; though there are
some particular cases in which the doctrine does not hold.[171]
[Footnote 168: Ibid. b. 1-8. [Greek: phanero\n de\ tou/tôn e(/kaston
dia\ tê=s e)pagôgê=s].]
[Footnote 169: Ibid. b. 8-12.]
[Footnote 170: Topic. IV. iii. p. 123, b. 12, seq.]
[Footnote 171: Ibid. b. 17-23: [Greek: e)/nstasis tou/tou o(/ti
u(giei/as kai\ no/sou ou)de\n metaxu/, kakou= de\ kai\ a)gathou=; ê)\
ei) e)/sti me/n ti a)mphoi=n a)na\ me/son, kai\ tô=n ei)dô=n kai\
tô=n genô=n, mê\ o(moi/ôs de/, a)lla\ tô=n me\n kat' a)po/phasin,
tô=n d' ô(s u(pokei/menon. _e)/ndoxon ga\r to\ o(moi/ôs a)mphoi=n_,
katha/per e)p' a)retê=s kai\ kaki/as, kai\ dikaiosu/nês kai\
a)diki/as; a)mphoi=n ga\r kata\ a)po/phasin ta\ a)na\ me/son.]]
Again, suppose different conditions: that there is no contrary to the
genus, but that there is a contrary to the species. You will examine
whether not merely the contrary of the species, but also the
intermediate between its two contraries, is included in the same
genus; for, if the two contraries are included therein, the
intermediate ought also to be included. This is a line of argument
_probable_ (_i.e._, conformable to general presumption, and
recommendable in a dialectical debate), though there are not wanting
examples adverse to it: thus, excess and defect are included in the
same genus evil, but the moderate or measured ([Greek: to\ me/trion])
is not in the genus evil, but in the genus good.[172] We must remark,
moreover, that though it be a probable dialectical argument, that,
wherever the genus has a contrary, the species will also have a
contrary, yet there are cases adverse to this principle. Thus,
sickness in general has for its contrary health in general; but
particular species of sickness (such as fever, ophthalmia, gout, &c.)
have no contrary.[173]
[Footnote 172: Ibid. b. 23-30.]
[Footnote 173: Ibid. b. 30-37.]
Such will be your way of procedure, if the thesis propounded be
Affirmative, and if you have to make out a negative against it. But
if, on the contrary, the thesis be Negative, so that you have to make
out an affirmative against it, you have then three lines of procedure
open. 1. The genus may have no contrary, while the species has a
contrary: in that case, you may perhaps be able to show that the
contrary of the species (subject) is included in the predicate of the
thesis (genus); if so, then the species also will be included
therein. 2. Or, if you can show that the intermediate between the
species and its contrary is included in the predicate (genus), then
that same genus will also include the species and its contrary; for,
wherever the intermediate is, there also are the two extremes between
which it is intermediate. 3. Lastly, if the genus has a contrary as
well as the species, you may be able to show that the contrary of the
species is included in the contrary of the genus; assuming which to
be the case, then the species itself will be included in the
genus.[174] These are the three modes of procedure, if your task is
to make out the negative.
[Footnote 174: Topic. IV. iii. p. 124, a. 1-9.]
If the genus enunciated by the thesis be a true one, all the
Derivatives and Collaterals of the predicate will be fit and suitable
for those of the subject. Thus, if justice be a sort of science,
justly will be scientifically, and the just man will be a scientific
man. This _locus_ is useful to be kept in mind, whether you have to
make out an affirmative or a negative.[175] You may reason in the
same way about the _Analoga_ of the predicate and the subject; about
the productive and destructive causes of each; the manifestations
present, past, and future, of each, &c.[176]
[Footnote 175: Ibid. a. 10-14.]
[Footnote 176: Ibid. iv. p. 124, a. 15-34.]
When the opposite of the species (subject) is Privative, the thesis
will be open to attack in two ways. 1. If the privative opposite be
contained in the predicate, the subject itself will not be contained
therein; for it is a general truth that a subject and its privative
opposite are never both of them contained in the same lowest genus:
thus, if vision is sensible perception, blindness is not sensible
perception. 2. If both the species and the genus have privative
opposites, then if the privative opposite of the species be contained
in the privative opposite of the genus, the species itself will also
be contained in the genus; if not, not. Thus, if blindness be an
inability of sensible perception, vision will be a sensible
perception. This last _locus_ will be available, whether you are
making out an affirmative or a negative.[177]
[Footnote 177: Ibid. a. 35-b. 6.]
If the predicate of the thesis be a true genus, you may convert the
thesis simply, having substituted for the predicate the denial of its
Contradictory; if not, not. _Vice versâ_, if the new proposition so
formed be true, the predicate of the thesis will be a true genus; if
not, not. Thus, if good be the true genus of pleasurable, nothing
that is not good will be pleasurable. This _locus_ also will serve
both for making out an affirmative and for making out a
negative.[178]
[Footnote 178: Topic. IV. iv. p. 124, b. 7-14: [Greek: pa/lin e)pi\
tô=n a)popha/seôn skopei=n a)na/palin], &c.]
If the subject (species) of the thesis be a Relative, you will
examine whether the predicate (genus) be relative also; if not, it
will not be the true genus of the subject. The converse of this rule,
however, will not hold; and indeed the rule itself is not absolutely
universal.[179] You may also argue that, if the correlate of the
genus be not the same as the correlate of the species, the genus
cannot be truly predicated of that species: thus, half is the
correlate of double, but half is not the proper correlate of
multiple; therefore, multiple is not the true genus of double. But
your argument may here be met by contradictory instances; thus,
cognition has reference to the _cognitum_, but _habitus_ and
_dispositio_ (the genera to which _cognitio_ belongs) do not refer to
_cognitum_ but to _anima_.[180] You may also examine whether the
correlate, when applied to the genus, is put in the same case
(_e.g._, genitive, dative, &c.) as when it is applied to the species:
if it be put into a different case, this affords presumption that the
genus is not a true genus; though here again instances may be
produced showing that your presumption will not hold universally.
Farther, you will observe whether the correlates thus similarly
inflected reciprocate like the species and genus; if not, this will
furnish you with the same adverse presumption.[181]
[Footnote 179: Ibid. b. 15-22.]
[Footnote 180: Ibid. b. 23-34.]
[Footnote 181: Ibid. b. 35, seq.]
Again, examine whether the correlate of the genus is genus to the
correlate of the species; if it be not so, you may argue that the
genus is not truly predicated. Thus, if the thesis affirms that
_perceptio_ is the genus of _cognitio_, it will follow that
_percipibile_ is the genus of _cognoscibile_. Now this cannot be
maintained; for there are some _cognoscibilia_ which are not
perceivable, _e.g._, some _cogitabilia_ (_intelligibilia_, [Greek:
noêta/]). Since therefore _percipibile_ is not the true genus of
_cognoscibile_, neither can _perceptio_ be the true genus of
_cognitio_.[182]
[Footnote 182: Ibid. p. 125, a. 25-32: [Greek: o(ra=n de\ kai\ ei)
tou= a)ntikeime/nou to\ a)ntikei/menon ge/nos, oi(=on ei) tou=
diplasi/ou to\ pollapla/sion kai\ tou= ê(mi/seos to\ pollostêmo/rion;
dei= ga\r to\ a)ntikei/menon tou= a)ntikeime/nou ge/nos ei)=nai.]
We must take note here of the large sense in which Aristotle uses
[Greek: A)ntikei/mena]--_Opposita_, including as one of the four
varieties _Relata_ and _Correlata_ = _Relativé-Opposita_ (to use a
technical word familiar in logical manuals). I have before (_supra_,
p. 105) remarked the inconvenience of calling the Relative _opposite_
to its Correlate; and have observed that it is logically incorrect to
treat _Relata_ as a species or mode of the genus _Opposita_. The
reverse would be more correct: we ought to rank _Opposita_ or a
species or mode under the genus _Relata_. Since Aristotle numbers
_Relata_ among the ten Categories, he ought to have seen that it
cannot be included as a subordinate under any superior genus.]
Suppose the thesis predicates of memory that it is--a continuance of
cognition. This will be open to attack, if the predicate be affirmed
as the genus (or even as the accident) of the subject. For every
continuance must be _in_ that which continues. But memory is of
necessity _in_ the soul; it cannot therefore be _in_ cognition.[183]
There is another ground on which the thesis will be assailable, if it
defines memory to be--a habit or acquirement retentive of belief.
This will not hold, because it confounds habit or disposition with
act; which last is the true description of memory. The opposite error
will be committed if the respondent defines perceptivity to be
a--movement through or by means of the body. Here perceptivity, which
is a habit or disposition, is ranked under movement, which is the act
exercising the same, _i.e._, perceptivity in actual exercise.[184]
Or, the mistake may be made of ranking some habit or disposition
under the power consequent on the possession thereof, as if this
power were the superior genus: thus the respondent may define
gentleness to be a continence of anger; courage, a continence of
fears; justice, a continence of appetite of lucre. But the genus here
assigned is not a good one: for a man who feels no anger is called
gentle; a man who feels no fear is called courageous; whereas the
continent man is he who feels anger or fear, but controls them. Such
controlling power is a natural consequence of gentleness and courage,
insomuch that, if the gentle man happened to feel anger, or the
courageous man to feel fear, each would control these impulses; but
it is no part of the essence thereof, and therefore cannot be the
genus under which they fall.[185] A like mistake is made if pain be
predicated as the genus of anger, or supposition as the genus of
belief. The angry man doubtless feels pain, but his pain precedes his
anger in time, and is the antecedent cause thereof; now the genus can
never precede its species in time. So also a man may have the same
supposition sometimes with belief, sometimes without it; accordingly,