tual likeness of the
thing known: whence it would follow, if the power of the angel knew
all things by itself, that it was the likeness and act of all things.
Wherefore there must needs be added to the angels' intellective
power, some intelligible species, which are likenesses of things
understood: for it is by participation of the Divine wisdom and not
by their own essence, that their intellect can be actually those
things which they understand. And so it is clear that not everything
belonging to a natural habit can belong to the power.

Reply Obj. 3: Nature is not equally inclined to cause all the various
kinds of habits: since some can be caused by nature, and some not, as
we have said above. And so it does not follow that because some
habits are natural, therefore all are natural.
________________________

SECOND ARTICLE [I-II, Q. 51, Art. 2]

Whether Any Habit Is Caused by Acts?

Objection 1: It would seem that no habit is caused by acts. For habit
is a quality, as we have said above (Q. 49, A. 1). Now every quality
is caused in a subject, according to the latter's receptivity. Since
then the agent, inasmuch as it acts, does not receive but rather
gives: it seems impossible for a habit to be caused in an agent by
its own acts.

Obj. 2: Further, the thing wherein a quality is caused is moved to
that quality, as may be clearly seen in that which is heated or
cooled: whereas that which produces the act that causes the quality,
moves, as may be seen in that which heats or cools. If therefore
habits were caused in anything by its own act, it would follow that
the same would be mover and moved, active and passive: which is
impossible, as stated in Physics iii, 8.

Obj. 3: Further, the effect cannot be more noble than its cause. But
habit is more noble than the act which precedes the habit; as is
clear from the fact that the latter produces more noble acts.
Therefore habit cannot be caused by an act which precedes the habit.

_On the contrary,_ The Philosopher (Ethic. ii, 1, 2) teaches that
habits of virtue and vice are caused by acts.

_I answer that,_ In the agent there is sometimes only the active
principle of its act: for instance in fire there is only the active
principle of heating. And in such an agent a habit cannot be caused
by its own act: for which reason natural things cannot become
accustomed or unaccustomed, as is stated in _Ethic._ ii, 1. But a
certain agent is to be found, in which there is both