Mediaeval man lived in a marvellously ordered and disciplined universe. Both reason and faith taught him that God was in His heaven, and if all was not well with the world, it was the fault of man and his revolt, of sin and moral evil, not the fault of God. Through all the ranges of created being, from prima materia to the very infinitude of God Himself, there was a necessary order and hierarchy, for the simple reason that God had so disposed all things. Only man was capable of violating that natural order and its concomitant law. The tradition of philosophy supported this pervasive thesis of revelation, at least without contradiction; and the fact of sin was selfevident: not man's irredeemable corruption and futility, as in the great heresies of Manichaeus, the Albigenses and later of Calvin, but his tragic tendency toward evil and moral disintegration unless sanctified by supernatural aid. This aid would be forthcoming with absolute certainty if man assumed his personal responsibility for the evil in his own life and if he cooperated in an intimate way with the scheme of divine redemption. Time and the secular order therefore could be redeemed, from generation to generation, because God had intervened in time and had interfered with the natural state of man in the climactic events of the Incarnation and the Crucifixion. But the redemption of society must depend inevitably on the redemption of the individual human person; St. Paul's “redeem the time for the days are evil” meant “redeem one's self, and the days will be better.” Any other philosophy of reform must lead, as we know now, to the subjection of the human person to slavery, whatever the complexion of the particular totalitarian “ism.” On the other hand, the Christian hope and desire for moral improvement, and thus for social betterment, was and no doubt continues to be the basis for the ultimate optimism of Western civilization.