It is by quality that we distinguish the differences which inhere in
being, as well as the actualizations, the beautiful or ugly actions,
and in general, all that is particular. Only very rarely do we discover
in quantity differences which constitute species; so much is this the
case, that it is generally divided by its characteristic qualities. We
must therefore leave quantity aside, and that leads us to wonder how we
may divide quality itself (since it is made use of to distinguish other
things).[407]