oreknowledge (_scientia media_), is a
question in dispute between Thomists and Molinists.(100)

Merely sufficient grace (_gratia mere sufficiens_) is that divine
assistance whereby God communicates to the human will full power to
perform a salutary act (_posse_) but not the action itself (_agere_).

The division of grace into efficacious and merely sufficient is not
identical with that into prevenient and cooeperating. Cooeperating grace
does not _ex vi notionis_ include with infallible certainty the salutary
act. It may indeed be efficacious, but in matter of fact frequently fails
to attain its object because the will offers resistance.

a) The existence of efficacious graces is as certain as that there is a
Heaven filled with Saints. God would be neither omnipotent nor infinitely
wise if all His graces were frustrated by the free-will of man. St.
Augustine repeatedly expresses his belief in the existence of efficacious
graces. Thus he writes in his treatise on Grace and Free-Will: "It is
certain that we act whenever we set to work; but it is He [God] who causes
us to act, by giving thoroughly efficacious powers to the will."(101) And
in another treatise: "[Adam] had received the ability (_posse_) if he
would [_gratia sufficiens_], but he had not the will to exercise that
ability [_gratia efficax_]; for if he had possessed that will, he would
have persevered."(102)

b) Before demonstrating the existence of sufficient grace it is necessary,
in view of certain heretical errors, carefully to define the term.

{~GREEK SMALL LETTER ALPHA~}) Actual grace may be regarded either in its intrinsic energy or power
(_virtus_, _potestas agendi_) or in its extrinsic efficacy (_efficientia_,
_efficacitas_). All graces are efficacious considered in their intrinsic
energy, because all confer the physical and moral power necessary to
perform the salutary act for the sake of which they are bestowed. From
this point of view, therefore, and _in actu primo_, there is no real but a
purely logical distinction between efficacious and merely sufficient
grace. If we look to the final result, however, we find that this differs
according as the will either freely cooeperates with grace or refuses its
cooeperation. If the will cooeperates, grace becomes truly efficacious; if
the will resists, grace remains "merely sufficient." In other words,
merely sufficient grace confers full power to act, but is rendered
ineffective by the resistance of the