and 'good'. Opposites in the sense of 'privatives' and 'positives'
are' blindness' and 'sight'; in the sense of affirmatives and
negatives, the propositions 'he sits', 'he does not sit'.
(i) Pairs of opposites which fall under the category of relation are
explained by a reference of the one to the other, the reference
being indicated by the preposition 'of' or by some other
preposition. Thus, double is a relative term, for that which is double
is explained as the double of something. Knowledge, again, is the
opposite of the thing known, in the same sense; and the thing known
also is explained by its relation to its opposite, knowledge. For
the thing known is explained as that which is known by something, that
is, by knowledge. Such things, then, as are opposite the one to the
other in the sense of being correlatives are explained by a
reference of the one to the other.
(ii) Pairs of opposites which are contraries are not in any way
interdependent, but are contrary the one to the other. The good is not
spoken of as the good of the had, but as the contrary of the bad,
nor is white spoken of as the white of the black, but as the
contrary of the black. These two types of opposition are therefore
distinct. Those contraries which are such that the subjects in which
they are naturally present, or of which they are predicated, must
necessarily contain either the one or the other of them, have no
intermediate, but those in the case of which no such necessity
obtains, always have an intermediate. Thus disease and health are
naturally present in the body of an animal, and it is necessary that
either the one or the other should be present in the body of an
animal. Odd and even, again, are predicated of number, and it is
necessary that the one or the other should be present in numbers.
Now there is no intermediate between the terms of either of these
two pairs. On the other hand, in those contraries with regard to which
no such necessity obtains, we find an intermediate. Blackness and
whiteness are naturally present in the body, but it is not necessary