δ) A final question forces itself upon the enquiring mind, _viz._: Is sanctifying grace capable of an indefinite increase, or is there a limit beyond which it cannot grow? In trying to find an answer to this question we must draw a careful distinction between the absolute and the ordinary power of God. There is no intrinsic contradiction in the assumption that grace can be indefinitely augmented. True, it can never become actually infinite, as this would involve an absurdity.(1199) But if we regard the power of God as He sees fit to exercise it in the present economy (_potentia Dei ordinata_), we find that it is limited by two sublime ideals of holiness to which neither man nor angel can attain, _viz._: the overflowing measure of sanctifying grace in the human soul of our Lord Jesus Christ(1200) and the “fulness of grace” granted to His Mother.(1201) Though these ideals are beyond our reach, we must not be discouraged, but try to approach them as nearly as possible.(1202) *Thesis III: Sanctifying grace is lost by mortal sin.* This thesis also embodies an article of faith. Proof. Calvin asserted that neither justification nor faith can be lost by those who are predestined to salvation, and that the unpredestined are never truly justified. Luther held that justifying grace is lost solely through the sin of infidelity. Against the former the Council of Trent declared: “If anyone saith that a man once justified can sin no more, nor lose grace, and that therefore he that falls and sins was never truly justified; ... let him be anathema.”(1203) Against the latter the same council defined: “If anyone saith that there is no mortal sin but that of infidelity, or that grace once received is not lost by any other sin, however grievous and enormous, save by that of infidelity, let him be anathema.”(1204) At the same time, however, the Holy Synod expressly declared that venial sin does not destroy the state of grace: “For although during this mortal life, men, how holy and just soever, at times fall into at least light and daily sins, which are also called venial, they do not therefore cease to be just.”(1205)