Melanchthon is primarily known for his educational influence as the praeceptor Germaniae. In a carefully documented study Jensen presents him here as the founder of the natural law tradition in Lutheranism, pioneering the systematic treatment of politics in the universities, and establishing Aristotelian virtue ethics as central to Lutheran moral philosophy. His humanist approach led him to significant differences from Luther's views. For Melanchthon the law of nature was divinely inscribed in people's minds. The political realm, with its concern for law and order, was the domain of philosophy and must be sharply distinguished from that of the Gospel. ‘Christian happiness is not found in civil action, but in the faith and knowledge of God’ (p. 60). Melanchthon sharply criticised radicals such as Karlstadt, Schappeler and Müntzer, fanatics ‘who claim that servitude is contrary to the Gospel’ (p. 80). As Jensen summarises, ‘Melanchthon argued that politics had as little to do with the Christian faith as architecture or medicine (p. 190). Any attempt to create a Christian society along biblical lines could only result in tyrannical behaviour, undermine the established laws and endanger order and liberty. Jensen reviews Melanchthon's views historically and argues that they were modified by the shifting cultural and political situation in which he found himself. He discerns three phases: an early focus on Ciceronian models, moving to a more Aristotelian account of political authority based on natural law, and culminating in the 1530s in a legitimising of emergent confessionalism: obedience to God should be enforced by the ruler, who has the right, as in the Schmalkaldic War, to resist any threat to true religion. Luther, on the other hand, based the right to resistance mainly on apocalyptic and theological considerations.