rational creature
cannot of its own power attain to its beatitude, which consists in
the vision of God, as is clear from what has gone before (Q. 12, A.
4), that it needs to be moved by God towards its beatitude. Therefore
there must be some one determined thing to which every rational
creature is directed as to its last end.

Now this one determinate object cannot, in the vision of God, consist
precisely in that which is seen; for the Supreme Truth is seen by all
the blessed in various degrees: but it is on the part of the mode of
vision, that diverse terms are fixed beforehand by the intention of
Him Who directs towards the end. For it is impossible that as the
rational creature is led on to the vision of the Supreme Essence, it
should be led on in the same way to the supreme mode of vision, which
is comprehension, for this belongs to God only; as is evident from
what was said above (Q. 12, A. 7; Q. 14, A. 3). But since infinite
efficacy is required for comprehending God, while the creature's
efficacy in beholding is only finite; and since every finite being is
in infinite degrees removed from the infinite; it comes to pass that
the rational creature understands God more or less clearly according
to infinite degrees. And as beatitude consists in vision, so the
degree of vision lies in a determinate mode of the vision.

Therefore every rational creature is so led by God to the end of its
beatitude, that from God's predestination it is brought even to a
determinate degree of beatitude. Consequently, when that degree is
once secured, it cannot pass to a higher degree.

Reply Obj. 1: Merit belongs to a subject which is moving towards its
end. Now the rational creature is moved towards its end, not merely
passively, but also by working actively. If the end is within the
power of the rational creature, then its action is said to procure
the end; as man acquires knowledge by reflection: but if the end be
beyond its power, and is looked for from another, then the action
will be meritorious of such end. But what is already in the ultimate
term is not said to be moved, but to have been moved. Consequently,
to merit belongs to the imperfect charity of this life; whereas
perfect charity does not merit but rather enjoys the reward. Even as
in acquired habits, the operation preceding the habit is productive
of the habit; but the operation from an acquired habit is both
perfect and enjoyable. In the same way the act of perfect ch