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 (Question [49], Article [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.

❌ Objection 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.

❌ Objection 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.