ious habit is worse than a vicious act.

Obj. 3: Further, a cause is more potent than its effect. But a habit
produces its actions both as to their goodness and as to their
badness. Therefore a habit is more potent than its act, both in
goodness and in badness.

_On the contrary,_ A man is justly punished for a vicious act; but
not for a vicious habit, so long as no act ensues. Therefore a
vicious action is worse than a vicious habit.

_I answer that,_ A habit stands midway between power and act. Now it
is evident that both in good and in evil, act precedes power, as
stated in _Metaph._ ix, 19. For it is better to do well than to be
able to do well, and in like manner, it is more blameworthy to do
evil, than to be able to do evil: whence it also follows that both in
goodness and in badness, habit stands midway between power and act,
so that, to wit, even as a good or evil habit stands above the
corresponding power in goodness or in badness, so does it stand below
the corresponding act. This is also made clear from the fact that a
habit is not called good or bad, save in so far as it induces to a
good or bad act: wherefore a habit is called good or bad by reason of
the goodness or badness of its act: so that an act surpasses its
habit in goodness or badness, since "the cause of a thing being such,
is yet more so."

Reply Obj. 1: Nothing hinders one thing from standing above another
simply, and below it in some respect. Now a thing is deemed above
another simply if it surpasses it in a point which is proper to both;
while it is deemed above it in a certain respect, if it surpasses it
in something which is accidental to both. Now it has been shown from
the very nature of act and habit, that act surpasses habit both in
goodness and in badness. Whereas the fact that habit is more lasting
than act, is accidental to them, and is due to the fact that they are
both found in a nature such that it cannot always be in action, and
whose action consists in a transient movement. Consequently act
simply excels in goodness and badness, but habit excels in a certain
respect.

Reply Obj. 2: A habit is several acts, not simply, but in a certain
respect, i.e. virtually. Wherefore this does not prove that habit
precedes act simply, both in goodness and in badness.

Reply Obj. 3: Habit causes act by way of efficient causality: but act
causes habit, by way of final causality, in respect of which we
consider the nature of good and evil.