Aristotle
u(pa/rchon a)/n te mêdeni/, polla\ proene/gkanti a)xiôte/on katho/lou
o(mologei=n, ê)\ phe/rein e)/nstasin e)pi\ ti/nos ou)ch ou(/tôs.]]
[Footnote 150: Topic. III. vi. p. 120, a. 37-b. 6. It would appear
from the examples here given by Aristotle--[Greek: o( chro/nos ou)
kinei=tai, o( chro/nos ou)/k e)sti ki/nêsis, ê( psuchê\ ou)/k e)stin
a)rithmo/s], that he considers these propositions as either
indefinite or particular.]
IV.
After this long catalogue of _Loci_ belonging to debate on
propositions of Accident, Aristotle proceeds to enumerate those
applicable to propositions of Genus and of Proprium. Neither Genus
nor Proprium is often made subject of debate as such; but both of
them are constituent elements of the debate respecting Definition,
which is of frequent occurrence.[151] For that reason, both deserve
to be studied.
[Footnote 151: Ibid. IV. i. p. 120, b. 12: [Greek: meta\ de\ tau=ta
peri\ tô=n pro\s to\ ge/nos kai\ to\ i)/dion e)piskepte/on; e)/sti
de\ tau=ta stoichei=a tô=n pro\s tou\s o(/rous; peri\ au)tô=n de\
tou/tôn o)liga/kis ai( ske/pseis gi/nontai toi=s dialegome/nois.]]
When the thesis propounded affirms that A is genus of B, you will run
over all the cognates of B, and see whether there is any one among
them respecting which A cannot be affirmed as genus. If there be,
this is a good argument against the thesis; for the genus ought to be
predicable of all. Next, whether what is really no more than an
accident is affirmed as genus, which ought to belong to the essence
of the subject. Perhaps (_e.g._) white is affirmed in the thesis as
being genus of snow; but white cannot be truly so affirmed; for it is
not of the essence of snow, but is only a quality or accident.[152]
Examine whether the predicate A comes under the definition already
given of an Accident,--that which may or may not be predicated of the
subject; also, whether A and B both fall under the same one out of
the ten Categories or Predicaments. If B the subject comes under
_Essentia_, or _Quale_, or _Ad Aliquid_, the predicate ought also to
belong to _Essentia_, or _Quale_, or _Ad Aliquid_: the species and
the genus ought to come under the same Category.[153] If this be not
the case in a thesis of Genus, the thesis cannot be maintained.
[Footnote 152: Ibid. b. 23-29.]
[Footnote 153: Ibid. p. 120, b. 36-p. 121, a. 9. [Greek: katho/lou d'
ei)pei=n u(po\ tê\n au)tê\n diai/resin dei= to\ ge/nos tô=| ei)/dei
ei)=nai.]
Aristotle here enunciates this as universally true, whereas if we
turn to Categor. p. 11, a. 24, seq. we shall find him declaring it
not to be universally true. Compare also Topic. IV. iv. p. 124, b.
15.]
You are aware that the species always partakes of the genus, while
the genus never partakes of the species; to _partake_ meaning that
the species includes the essence or definition of the genus, but the
genus never includes the essence or definition of the species. You
will examine, therefore, whether in the thesis propounded to you this
condition is realized; if not, the thesis may be refuted. Suppose,
_e.g._, that it enunciates some superior genus as including _Ens_ or
_Unum_. If this were true, the genus so assigned would still partake
of _Ens_ and _Unum_; for _Ens_ and _Unum_ maybe predicated of all
existences whatever. Therefore what is enunciated in the thesis as a
genus, cannot be a real genus.[154]
[Footnote 154: Topic. IV. i. p. 121, a. 10-19.]
Perhaps you may find something respecting which the subject (species)
may be truly affirmed, while the predicate (genus) cannot be truly
affirmed. If so, the predicate is not a real genus. Thus, the thesis
may enunciate _Ens_ or _Scibile_ as being the genus of _Opinabile_.
But this last, the species or subject _Opinabile_, may be affirmed
respecting _Non-Ens_ also; while the predicates _Ens_ or _Scibile_
(given as the pretended genus of _Opinabile_) cannot be affirmed
respecting _Non-Ens_. You can thus show that _Ens_ or _Scibile_ is
not the real genus of _Opinabile_.[155] The pretended species
_Opinabile_ (comprising as it does both _Ens_ and _Non-Ens_)
stretches farther than the pretended genus _Ens_ or _Scibile_:
whereas every real genus ought to stretch farther than any one or any
portion of its constituent species.[156] The thesis may thus be
overthrown, if there be any one species which stretches even equally
far or is co-extensive with the pretended genus.[157]
[Footnote 155: Ibid. a. 20-26.]
[Footnote 156: Ibid. b. 1-14. [Greek: stoichei=on de\ pro\s a(/panta
ta\ toiau=ta, to\ e)pi\ ple/on to\ ge/nos ê)\ to\ ei)=dos kai\ tê\n
diaphora\n le/gesthai; e)p' e)/latton ga\r kai\ ê( diaphora\ tou=
ge/nous le/getai.]]
[Footnote 157: Ibid. b. 4.]
It is a general truth that the same species cannot belong to two
distinct genera, unless one of the two be subordinate to the other,
or unless both of them be comprehended under some common higher
genus. You will examine, therefore, whether there is any other genus,
besides the predicate of the thesis, to which the subject of the
thesis can be referred. If there be some other genus, not under
either of the two conditions above indicated, the predicate
enunciated by the thesis cannot be the real genus of the subject.
Thus, if the thesis declares justice to be science (or to belong to
the genus science), you may remark that there is another distinct
genus (virtue) to which justice also belongs. In this particular
case, however, it would be replied that science and virtue can both
be referred to one and the same higher genus, viz., habit and
disposition. Therefore the thesis, Justice is science, will not be
truly open to objection on this ground.[158]
[Footnote 158: Topic. IV. ii. p. 121, b. 24, seq.]
Again, if the predicate of the thesis be the true genus of the
subject, all the higher genera in which the predicate is contained
must also be predicated _in Quid_ (as the predicate itself is**)
respecting the subject. This you must show by an induction of
particular instances, no counter-instance being producible.[159] If
the thesis enunciated does not conform to this condition, you will
have a good argument against it. You will also run over the
sub-species that are comprehended in the subject of the thesis,
considered as a genus; and you will examine whether the predicate of
the thesis (together with all its superior genera) is predicable
essentially or _in Quid_ of all these sub-species. If you can find
any one among these sub-species, of which it is not essentially
predicable, the predicate of the thesis is not the true genus of the
subject;[160] the like also, if the definitions of those genera are
not predicable of the subject or its sub-species.[161]
[Footnote 159: Ibid. p. 122, a. 5-19. [Greek: o(/ti de\ e(no\s e)n
tô=| ti/ e)sti katêgoroume/nou pa/nta ta\ loipa/, a)/nper
katêgorê=tai, e)n tô=| ti/ e)sti katêgorêthê/setai, di' e)pagôgê=s
lêpte/on.]]
[Footnote 160: Ibid. a. 21-b. 6.]
[Footnote 161: Ibid. b. 7-11. [Greek: ei) ou)=n diaphônei=, dê=lon
o(/ti ou) ge/nos to\ a)podothe/n.]]
Perhaps the thesis may enunciate as a genus what is really nothing
more than a differentia. It may also enunciate the differentia either
as a part of the genus or as a part of the species; or it may
enunciate the genus either as a part of the differentia or as a part
of the species. All these are attackable. The differentia is not a
genus, nor does it respond to the question _Quid est_, but to the
question _Quale quid est_. It is always either **more
extensive than the species, or co-extensive therewith.[162] If none
of the differentiæ belonging to a genus can be predicated of a
species, neither can the genus itself be predicated thereof. Thus,
neither odd nor even can be predicated of the soul; accordingly,
neither can the genus (number) be predicated of the soul.[163] If the
species be _prius naturâ_, so that when it disappears the enunciated
genus disappears along with it, this cannot be the real genus; nor,
if the enunciated genus or differentia can be supposed to disappear
and yet the species does not disappear along with them.[164] If the
species partakes of (includes in its essence) something contrary to
the enunciated genus, this last cannot be the real genus; nor, if the
species includes something which cannot possibly belong to what is in
that genus. Thus, if the soul partakes of (or includes in its
essence) life, and if no number can possibly live, the soul cannot be
a species of number.[165]
[Footnote 162: Ibid. b. 12-p. 123, a. 10. [Greek: ou)de\ dokei=
mete/chein ê( diaphora\ tou= ge/nous; pa=n ga\r to\ mete/chon tou=
ge/nous ê)\ ei)=dos ê)\ a)/tomo/n e)stin. a)ei\ ga\r ê( diaphora\
e)p' i)/sês ê)\ e)pi\ plei=on tou= ei)/dous le/getai.--e)pi\ ple/on
te ga\r to\ ge/nos tê=s diaphora=s dei= le/gesthai, kai\ mê\
mete/chein tê=s diaphora=s.]
As an example to illustrate the enclosing of the genus within the
species ([Greek: ei) to\ ge/nos ei)s to\ ei)=dos e)/thêken]),
Aristotle cites a definition given by Plato, who defined [Greek: tê\n
kata\ to/pon ki/nêsin], as [Greek: phora/n]. Now [Greek: phora\] is
less extensive in its meaning than [Greek: ê( kata\ to/pon ki/nêsis],
which includes [Greek: ba/disis] and other terms of motion apart from
or foreign to [Greek: phora/].--Example of enunciating differentia as
a genus is, if immortal be given as the genus to which a god belongs.
Immortal is the differentia belonging to [Greek: zô=|on], and
constituting therewith the species god.--Example of enclosing the
differentia in the genus is, if odd be given as the essence of number
([Greek: o(/per a)rithmo/n]).--Example of enclosing differentia in
the species is, if immortal be put forward as the essence of a god
([Greek: o(/per theo/n]).--Example of enclosing the genus in the
differentia is, number given as the essence of the odd.--Example of
enunciating the genus as a differentia is, when change of place is
given as the differentia of [Greek: phora/].]
[Footnote 163: Topic. IV. ii. p. 123, a. 11-14.]
[Footnote 164: Ibid. a. 14-19.]
[Footnote 165: Ibid. iii. a. 20-26.]
Again, the generic term and the specific term ought to be univocal in
signification. You must examine (according to the tests indicated in
the First Book of the Topica) whether it be taken equivocally in the
thesis. If it be so, you have a ground of attack, and also if it be
taken metaphorically; for every genus ought to be enunciated in the
proper sense of the term, and no metaphor can be allowed to pass as a
genus.[166] Note farther that every true genus has more than one
distinct species. You will, therefore, examine whether any other
species, besides the subject of the thesis, can be suggested as
belonging to the predicate of the thesis. If none, that predicate
cannot be the true genus of the subject.[167]
[Footnote 166: Ibid. a. 27-37. [Greek: skopei=n de\ kai\ ei) to\
metaphora=| lego/menon ô(s ge/nos a)pode/dôken, oi(=on tê\n
sôphrosu/nên sumphôni/an; pa=n ga\r ge/nos kuri/ôs kata\ tô=n ei)dô=n
katêgorei=tai, ê( de\ sumphôni/a kata\ tê=s sôphrosu/nês ou) kuri/ôs
a)lla\ metaphora=|; pa=sa ga\r sumphôni/a e)n phtho/ggois.]]
[Footnote 167: Topic. IV. iii. p. 123, a. 30.]
Several _loci_ are furnished by Contraries, either to the species or
the genus. If there be something contrary to the species, but nothing
contrary to the genus, then that which is contrary to the species
ought to be included under the same genus as the species itself; but,
if there be something contrary to the species, and also something
contrary to the genus, then that which is contrary to the species
ought to be included in that which is contrary to the genus. Each of
these doctrines you will have to make good by induction of particular
cases.[168] If that which is contrary to the species be a genus