If, however, the virtue remain
unimpaired, outward changes can indeed disturb such like happiness,
in so far as they hinder many acts of virtue; but they cannot take it
away altogether because there still remains an act of virtue, whereby
man bears these trials in a praiseworthy manner. And since the
happiness of this life can be lost, a circumstance that appears to be
contrary to the nature of happiness, therefore did the Philosopher
state (Ethic. i, 10) that some are happy in this life, not simply,
but "as men," whose nature is subject to change.

But if we speak of that perfect Happiness which we await after this
life, it must be observed that Origen (Peri Archon. ii, 3), following
the error of certain Platonists, held that man can become unhappy
after the final Happiness.

This, however, is evidently false, for two reasons. First, from the
general notion of happiness. For since happiness is the "perfect and
sufficient good," it must needs set man's desire at rest and exclude
every evil. Now man naturally desires to hold to the good that he
has, and to have the surety of his holding: else he must of necessity
be troubled with the fear of losing it, or with the sorrow of knowing
that he will lose it. Therefore it is necessary for true Happiness
that man have the assured opinion of never losing the good that he
possesses. If this opinion be true, it follows that he never will
lose happiness: but if it be false, it is in itself an evil that he
should have a false opinion: because the false is the evil of the
intellect, just as the true is its good, as stated in _Ethic._ vi, 2.
Consequently he will no longer be truly happy, if evil be in him.

Secondly, it is again evident if we consider the specific nature of
Happiness. For it has been shown above (Q. 3, A. 8) that man's
perfect Happiness consists in the vision of the Divine Essence. Now
it is impossible for anyone seeing the Divine Essence, to wish not to
see It. Because every good that one possesses and yet wishes to be
without, is either insufficient, something more sufficing being
desired in its stead; or else has some inconvenience attached to it,
by reason of which it becomes wearisome. But the vision of the Divine
Essence fills the soul with all good things, since it unites it to
the source of all goodness; hence it is written (Ps. 16:15): "I shall
be satisfied when Thy glory shall appear"; and (Wis. 7:11): "All good
things came to me together with her," i.e.