The Complete Aristotle (eng.)

‘sight’ is a form of
‘sensation’.
    Again, look at the negations of the genus and species and
convert the order of terms, according to the method described in
the case of Accident: e.g. if the pleasant be a kind of good, what
is not good is not pleasant. For were this no something not good as
well would then be pleasant. That, however, cannot be, for it is
impossible, if ‘good’ be the genus of pleasant, that anything not
good should be pleasant: for of things of which the genus is not
predicated, none of the species is predicated either. Also, in
establishing a view, you should adopt the same method of
examination: for if what is not good be not pleasant, then what is
pleasant is good, so that ‘good’ is the genus of ‘pleasant’.
    If the species be a relative term, see whether the genus be a
relative term as well: for if the species be a relative term, so
too is the genus, as is the case with ‘double’ and ‘multiple’: for
each is a relative term. If, on the other hand, the genus be a
relative term, there is no necessity that the species should be so
as well: for ‘knowledge’is a relative term, but not so ‘grammar’.
Or possibly not even the first statement would be generally
considered true: for virtue is a kind of ‘noble’ and a kind of
‘good’ thing, and yet, while ‘virtue’ is a relative term, ‘good’
and ‘noble’ are not relatives but qualities. Again, see whether the
species fails to be used in the same relation when called by its
own name, and when called by the name of its genus: e.g. if the
term ‘double’ be used to mean the double of a ‘half’, then also the
term ‘multiple’ ought to be used to mean multiple of a ‘half’.
Otherwise ‘multiple’ could not be the genus of ‘double’.
    Moreover, see whether the term fail to be used in the same
relation both when called by the name of its genus, and also when
called by those of all the genera of its genus. For if the double
be a multiple of a half, then ‘in excess of ‘will also be used in
relation to a ‘half’: and, in general, the double will be called by
the names of all the higher genera in relation to a ‘half’. An
objection may be raised that there is no necessity for a term to be
used in the same relation when called by its own name and when
called by that of its genus: for ‘knowledge’ is called knowledge
‘of an object’, whereas it is called a ‘state’ and ‘disposition’
not of an ‘object’ but of the ‘soul’.
    Again, see whether the genus and the species be used in the same
way in respect of the inflexions they take, e.g. datives and
genitives and all the rest. For as the species is used, so should
the genus be as well, as in the case of ‘double’ and its higher
genera: for we say both ‘double of’ and ‘multiple of’ a thing.
Likewise, also, in the case of ‘knowledge’: for both knowledge’
itself and its genera, e.g. ‘disposition’ and ‘state’, are said to
be ‘of’ something. An objection may be raised that in some cases it
is not so: for we say ‘superior to’ and ‘contrary to’ so and so,
whereas ‘other’, which is the genus of these terms, demands not
‘to’ but ‘than’: for the expression is ‘other than’ so and so.
    Again, see whether terms used in like case relationships fail to
yield a like construction when converted, as do ‘double’ and
‘multiple’. For each of these terms takes a genitive both in itself
and in its converted form: for we say both a half of’ and ‘a
fraction of’ something. The case is the same also as regards both
‘knowledge’ and ‘conception’: for these take a genitive, and by
conversion an ‘object of knowledge’ and an ‘object of conception’
are both alike used with a dative. If, then, in any cases the
constructions after conversion be not alike, clearly the one term
is not the genus of the other.
    Again, see whether the species and the genus fail to be used in
relation to an equal number of things: for the general view is that
the uses of both are alike and equal in number, as is the case with
‘present’ and ‘grant’. For a present’ is of something or to some
one, and also a ‘grant’ is of something and to some one: and
‘grant’ is the genus of ‘present’, for a ‘present’ is a ‘grant that
need not be returned’. In some cases, however, the number of
relations in which the terms are used happens not to be equal, for
while ‘double’ is double of