M oRE than thirty years ago Benedetto Croce called for examination of the points of contact between the new Renaissance political thought and the apparently contradictory ideas of the Reformation.1 He thought that the assimilation of Machiavelli's ideas in the West might contain valuable clues as to how such contact had been accomplished. Figgis2 and Troeltsch3 pointed out some of the relationships between the Florentine and the Reformers; but both these great historians, concentrating on the thought of Martin Luther, did not go much beyond passing references to this problem. Perhaps the crux of the assimilation of Machiavellian ideas lies not in the thought of this or that reformer, but in the general tension between religious presuppositions and political realities. As the religious conflict during Tudor and Stuart times became a struggle for power and sovereignty, secular political ideas won a larger market. English divines had much at stake in the fight against heretical foes, both foreign and domestic. The study of casuistry, or the adjustment of the general Christian framework of ethics to meet new situations and dangers, can furnish a fruitful approach to the problem of how far "Machiavellian" ideas penetrated the thought of Western Christianity. Though we shall concentrate on England, it is possible that such an analysis may bear similar fruit if applied to Christian thought on the Continent.4