Augustine of Hippo : With God there is no injustice. Thus [Paul] immediately added, "For the Scripture says to Pharaoh, 'For this very purpose I raised you up, that I may show through you my power and that my name may be proclaimed in all the earth.' " Then, having said this, he draws a conclusion that looks both ways, that is, toward mercy and toward judgment: "Therefore," he says, "he has mercy on whom he wills, and whom he wills he hardens." He shows mercy out of his great goodness; he hardens out of no unfairness at all. In this way neither does he who is saved have a basis for glorying in any merit of his own; nor does the man who is damned have a basis for complaining of anything except what he has fully merited. For grace alone separates the redeemed from the lost, all having been mingled together in the one mass of perdition, arising from a common cause which leads back to their common origin. — Enchiridion 25.99