tecedent and
consequent are impossible: as if one were to say: "If man is a
donkey, he has four feet." Or he may be understood to mean that God
can do some things which now seem to be evil: which, however, if He
did them, would then be good. Or he is, perhaps, speaking after the
common manner of the heathen, who thought that men became gods, like
Jupiter or Mercury.

Reply Obj. 3: God's omnipotence is particularly shown in sparing and
having mercy, because in this is it made manifest that God has
supreme power, that He freely forgives sins. For it is not for one
who is bound by laws of a superior to forgive sins of his own free
will. Or, because by sparing and having mercy upon men, He leads them
on to the participation of an infinite good; which is the ultimate
effect of the divine power. Or because, as was said above (Q. 21, A.
4), the effect of the divine mercy is the foundation of all the
divine works. For nothing is due to anyone, except on account of
something already given him gratuitously by God. In this way the
divine omnipotence is particularly made manifest, because to it
pertains the first foundation of all good things.

Reply Obj. 4: The absolute possible is not so called in reference
either to higher causes, or to inferior causes, but in reference to
itself. But the possible in reference to some power is named possible
in reference to its proximate cause. Hence those things which it
belongs to God alone to do immediately--as, for example, to create,
to justify, and the like--are said to be possible in reference to a
higher cause. Those things, however, which are of such kind as to be
done by inferior causes are said to be possible in reference to those
inferior causes. For it is according to the condition of the
proximate cause that the effect has contingency or necessity, as was
shown above (Q. 14, A. 1, ad 2). Thus is it that the wisdom of the
world is deemed foolish, because what is impossible to nature, it
judges to be impossible to God. So it is clear that the omnipotence
of God does not take away from things their impossibility and
necessity.
_______________________

FOURTH ARTICLE [I, Q. 25, Art. 4]

Whether God Can Make the Past Not to Have Been?

Objection 1: It seems that God can make the past not to have been.
For what is impossible in itself is much more impossible than that
which is only impossible accidentally. But God can do what is
impossible in itself, as to give sight to the blind