jection: though some
give another solution, as Simplicius says in his _Commentary on the
Predicaments._

Reply Obj. 3: This difference, "difficult to change," does not
distinguish habit from the other species of quality, but from
disposition. Now disposition may be taken in two ways; in one way, as
the genus of habit, for disposition is included in the definition of
habit (Metaph. v, text. 25): in another way, according as it is
divided against habit. Again, disposition, properly so called, can be
divided against habit in two ways: first, as perfect and imperfect
within the same species; and thus we call it a disposition, retaining
the name of the genus, when it is had imperfectly, so as to be easily
lost: whereas we call it a habit, when it is had perfectly, so as not
to be lost easily. And thus a disposition becomes a habit, just as a
boy becomes a man. Secondly, they may be distinguished as diverse
species of the one subaltern genus: so that we call dispositions,
those qualities of the first species, which by reason of their very
nature are easily lost, because they have changeable causes; e.g.
sickness and health: whereas we call habits those qualities which, by
reason of their very nature, are not easily changed, in that they
have unchangeable causes, e.g. sciences and virtues. And in this
sense, disposition does not become habit. The latter explanation
seems more in keeping with the intention of Aristotle: for in order
to confirm this distinction he adduces the common mode of speaking,
according to which, when a quality is, by reason of its nature,
easily changeable, and, through some accident, becomes difficultly
changeable, then it is called a habit: while the contrary happens in
regard to qualities, by reason of their nature, difficultly
changeable: for supposing a man to have a science imperfectly, so as
to be liable to lose it easily, we say that he is disposed to that
science, rather than that he has the science. From this it is clear
that the word "habit" implies a certain lastingness: while the word
"disposition" does not.

Nor does it matter that thus to be easy and difficult to change are
specific differences (of a quality), although they belong to passion
and movement, and not the genus of quality. For these differences,
though apparently accidental to quality, nevertheless designate
differences which are proper and essential to quality. In the same
way, in the genus of substance we often take accide