these qualities, may be contrary the one to the other; for that
which is unjust is contrary to that which is just, that which is
white to that which is black. This, however, is not always the
case. Red, yellow, and such colours, though qualities, have no
contraries.

If one of two contraries is a quality, the other will also be a
quality. This will be evident from particular instances, if we
apply the names used to denote the other categories; for
instance, granted that justice is the contrary of injustice and
justice is a quality, injustice will also be a quality: neither
quantity, nor relation, nor place, nor indeed any other category
but that of quality, will be applicable properly to injustice. So
it is with all other contraries falling under the category of
quality.

Qualities admit of variation of degree. Whiteness is predicated
of one thing in a greater or less degree than of another. This is
also the case with reference to justice. Moreover, one and the
same thing may exhibit a quality in a greater degree than it did
before: if a thing is white, it may become whiter.

Though this is generally the case, there are exceptions. For if
we should say that justice admitted of variation of degree,
difficulties might ensue, and this is true with regard to all
those qualities which are dispositions. There are some, indeed,
who dispute the possibility of variation here. They maintain that
justice and health cannot very well admit of variation of degree
themselves, but that people vary in the degree in which they
possess these qualities, and that this is the case with