The Complete Aristotle (eng.)

a
certain sense upon the given species, but neither of them is genus
to it. For when the angry man feels pain, the pain bas appeared in
him earlier than the anger: for his anger is not the cause of his
pain, but his pain of his anger, so that anger emphatically is not
pain. By the same reasoning, neither is conviction conception: for
it is possible to have the same conception even without being
convinced of it, whereas this is impossible if conviction be a
species of conception: for it is impossible for a thing still to
remain the same if it be entirely transferred out of its species,
just as neither could the same animal at one time be, and at
another not be, a man. If, on the other hand, any one says that a
man who has a conception must of necessity be also convinced of it,
then ‘conception’ and ‘conviction’ will be used with an equal
denotation, so that not even so could the former be the genus of
the latter: for the denotation of the genus should be wider.
    See, also, whether both naturally come to be anywhere in the
same thing: for what contains the species contains the genus as
well: e.g. what contains ‘white’ contains ‘colour’ as well, and
what contains ‘knowledge of grammar’ contains ‘knowledge’ as well.
If, therefore, any one says that ‘shame’ is ‘fear’, or that ‘anger’
is ‘pain’, the result will be that genus and species are not found
in the same thing: for shame is found in the ‘reasoning’ faculty,
whereas fear is in the ‘spirited’ faculty, and ‘pain’ is found in
the faculty of ‘desires’. (for in this pleasure also is found),
whereas ‘anger’ is found in the ‘spirited’ faculty. Hence the terms
rendered are not the genera, seeing that they do not naturally come
to be in the same faculty as the species. Likewise, also, if
‘friendship’ be found in the faculty of desires, you may take it
that it is not a form of ‘wishing’: for wishing is always found in
the ‘reasoning’ faculty. This commonplace rule is useful also in
dealing with Accident: for the accident and that of which it is an
accident are both found in the same thing, so that if they do not
appear in the same thing, clearly it is not an accident.
    Again, see if the species partakes of the genus attributed only
in some particular respect: for it is the general view that the
genus is not thus imparted only in some particular respect: for a
man is not an animal in a particular respect, nor is grammar
knowledge in a particular respect only. Likewise also in other
instances. Look, therefore, and see if in the case of any of its
species the genus be imparted only in a certain respect; e.g. if
‘animal’ has been described as an ‘object of perception’ or of
‘sight’. For an animal is an object of perception or of sight in a
particular respect only; for it is in respect of its body that it
is perceived and seen, not in respect of its soul, so that-’object
of sight’ and ‘object of perception’ could not be the genus of
‘animal’.
    Sometimes also people place the whole inside the part without
detection, defining (e.g.) ‘animal’ as an ‘animate body’; whereas
the part is not predicated in any sense of the whole, so that
‘body’ could not be the genus of animal, seeing that it is a
part.
    See also if he has put anything that is blameworthy or
objectionable into the class ‘capacity’ or ‘capable’, e.g. by
defining a ‘sophist’ or a ‘slanderer’, or a ‘thief’ as ‘one who is
capable of secretly thieving other people’s property’. For none of
the aforesaid characters is so called because he is ‘capable’ in
one of these respects: for even God and the good man are capable of
doing bad things, but that is not their character: for it is always
in respect of their choice that bad men are so called. Moreover, a
capacity is always a desirable thing: for even the capacities for
doing bad things are desirable, and therefore it is we say that
even God and the good man possess them; for they are capable (we
say) of doing evil. So then ‘capacity’ can never be the genus of
anything blameworthy. Else, the result will be that what is
blameworthy is sometimes desirable: for there will be a certain
form of capacity that is blameworthy.
    Also, see if he has put anything that is precious or desirable
for its own sake into the class ‘capacity’ or ‘capable’ or
‘productive’ of anything. For capacity, and what is capable or
productive of anything,