Shall the affections which consist in the forms and powers, and their
contraries, the privations, be called qualities?[267] If so, one kind
will no longer exist; and we shall have to reduce these things to
a unity, or category; that is why knowledge is called a form and a
power, and ignorance a privation and impotence. Must we also consider
impotence and sickness a form, because sickness and vice can and do
accomplish many things badly? Not so, for in this case he who missed
his aim would be exerting a power. Each one of these things exerts
its characteristic activity in not inclining towards the good; for it
could not do what was not in its power. Beauty certainly does have some
power; is it so also with triangularity? In general, quality should
not be made to consist in power, but rather in the disposition, and to
consider it as a kind of form of character. Thus the common element in
all qualities is found to be this form, this classification, which no
doubt is inherent in being, but which certainly is derivative from it.