To this high spirituality, with its rich emotional coloring, was united a power and subtlety of intellect such as is possessed by only the very greatest masters of the mind. The spiritual world in which Edwards moved was for him no mere shadowy realm of pious sentiment or vague aspiration, but a world whose main outlines, at least, were sharply defined for thought. He conceived it, namely, in accordance with the scheme of things systematized by Calvin, but originally wrought out with the compelling force of transcendent genius by Augustine. The theological thought of Augustine is concerned--to put the matter as simply as possible--with the elaboration of four fundamental ideas: the absolute sovereignty of God; the absolute dependence of man; the supernatural revelation of a divinely originated plan of salvation administered by the Church; and a philosophy of history according to which the whole created universe and the entire temporal course of events are ordered and governed from all eternity with reference to the establishment and triumph of a Kingdom of saints in the Church, the holy "City of God." Augustine's conception of the Church is modified, but not in principle rejected, by the Protestant theologians; the other features of the scheme remain substantially unchanged. The idea of God's absolute sovereignty leads naturally, in connection with the motives supplied by certain teachings of Scripture, Roman jurisprudence, Greek philosophy, and the experiences of a profound religious consciousness, to the doctrines of God's eternal foreknowledge, His "arbitrary," i.e., unconditional decrees,--the eternal world-plan,--predestination, election, the historic work of redemption, everlasting punishment for the unrepentant wicked, everlasting felicity for the elect saints. Over against the sovereignty of God stands man's absolute dependence, historically conditioned, as regards his present spiritual capacities, by the Fall, with original sin, total depravity, and the utter inability of man to recover by himself his lost heritage as its consequence. Hence the great, the essential tragedy of human life--man naturally corrupt, in slavery to sin, at enmity with God, utterly incompetent to change a condition in which, by a sort of natural necessity, he is the subject of God's vindictive justice, utterly dependent for salvation on the free, unmerited grace of God, who has mercy on whom He will have mercy, while whom He will He hardeneth, revealing alike in mercy and in punishment the majesty of His divine and sovereign attributes.