c) The infallibility with which efficacious grace works its effects is to be explained not by God’s absolute will, but by His infallible foreknowledge through the _scientia media_,—a Molinistic postulate which was first defined and scientifically demonstrated by Father Fonseca, S. J., the teacher of Suarez.(763) God foreknows not only the absolutely free acts (_futura_) of His rational creatures by the _scientia visionis_, but likewise their hypothetically free acts (_futuribilia_) by means of the _scientia media_, and hence He infallibly knows from all eternity what attitude the free-will of man would assume in each case if grace were given him. Consequently, when God, in the light of this eternal foreknowledge, actually bestows a grace, this grace will prove efficacious or inefficacious according as He has foreknown whether the will will give or withhold its consent. Thus can the infallibility of efficacious grace be reconciled with the dogma of free-will without prejudice to such other dogmas as final perseverance and the predestination of the elect, because God by virtue of the _scientia media_ has it absolutely in His power to give or withhold His graces in each individual case.(764) CRITICAL ESTIMATE OF MOLINISM.—Even the most determined opponents of Molinism admit that this system possesses three important advantages. a) First, it gives a satisfactory account of the sufficiency of “merely sufficient grace,” which in its physical nature does not differ essentially from efficacious grace. Second, Molinism safeguards free-will by denying that efficacious grace either physically or morally predetermines the will to one course of action. Third, Molinism explains in a fairly satisfactory manner why efficacious grace is infallibly efficacious. God in virtue of the _scientia media_ knows with metaphysical certainty from all eternity which graces in each individual case will prove efficacious through the free consent of the will and which will remain inefficacious, and is thereby enabled to bestow or withhold grace according to His absolute decrees. b) The question may justly be raised, however, whether, in endeavoring to safeguard freewill, the Molinists do not undervalue grace, which is after all the primary and decisive factor in the work of salvation.