To begin with, resemblance does not mean only belonging to the same
genus, nor mere confusion from more or less numerous characteristics,
as, for instance, by their forms. Things that possess resemblance,
therefore, are not opposites. Only things which have nothing identical
in respect to species are opposites;[414] though we must add that they
must belong to the same genus of quality. Thus, though they have no
intermediaries, we can classify as opposites the things which betray
no resemblance to each other; in which are found only characteristics
which do not approximate each other, and bear no kind of analogy to
each other. Consequently, objects which have something in common in the
respect of colors could not be contraries. Besides, not everything is
the contrary of every other thing; but one thing is only the contrary
of some other; and this is the case with tastes as well as with colors.
But enough of all this.