ersoever he will, he shall turn
it." "Who will be so foolish as to say," queries St. Augustine, "that God
cannot change the evil wills of men, whichever, whenever, and wheresoever
He chooses, and direct them to what is good?"(29) It is but rarely, of
course, that God grants to any man a summary victory over his sinful
nature; but this fact does not prevent the Church from praying:
"Vouchsafe, O Lord, to compel our wills to thee, even though they be
rebellious."(30)

b) Even more important than the moral causality of grace is its physical
causality. Man depends entirely on God for the physical strength necessary
to perform salutary works. Grace elevates the faculties of the soul to the
supernatural sphere, thereby enabling it to perform supernatural acts.

Physical is as distinct from moral causality in the order of grace as in
the order of nature. The holding out of a beautiful toy will not enable a
child to walk without support from its elders. Moral causality is
insufficient to enable a man to perform salutary acts. Grace (as we shall
show later) is absolutely, _i.e._ metaphysically, necessary for all
salutary acts, whether easy or difficult, and hence the incapacity of
nature cannot be ascribed solely to weakness and to the moral difficulty
resulting from sin, but must be attributed mainly to physical impotence. A
bird without wings is not merely impeded but utterly unable to fly;
similarly, man without grace is not only handicapped but absolutely
incapacitated for the work of salvation. Considered under this aspect,
actual grace is called _gratia elevans_, because it elevates man to the
supernatural state.(31)

This double causality of grace is well brought out in Perrone's classic
definition: "_Gratia actualis est gratuitum illud auxilium,_(_32_)_ quod
Deus_(_33_)_ per Christi merita_(_34_)_ homini lapso_(_35_)_ largitur, tum
ut eius infirmitati consulat,_(_36_)_ ... tum ut eum erigat ad statum
supernaturalem atque idoneum faciat ad actus supernaturales
eliciendos,_(_37_)_ ut iustificationem possit adipisci_(_38_)_ in eaque
iam consecuta perseverare, donec perveniat ad vitam aeternam._"(39) In
English: "Actual grace is that unmerited interior assistance which God, by
virtue of the merits of Christ, confers upon fallen man, in order, on the
one hand, to remedy his infirmity resulting from sin and, on the other, to
raise him to the supernatural order and thereby to render him capable of
performing supernatural acts