Abstract

At the latest following Pufendorf's Jus naturae et gentium , the attempt to develop natural law out of one basic principle is prominent. Although John Locke characterizes Pufendorf's natural law as worthy of emulation and his own Treatises of Government reveal obvious traces of Pufendorf's ideas, still one fails to find any influence by the "basic-principle idea." Furthermore, Locke never explicates the mathematically demonstrative principle for law and morals, which he introduced in his Essay Concerning Human Understanding . Locke, however, does indicate in his Reasonableness of Christianity of 1695 that he sees the execution of such a program unrealistic at least by this point in time. He instead develops a form of heurism, which, in reliance on the New Testament , permits him to introduce a rational moral theory and a rational natural law. His natural law theory reveals its rationality not through its justification or by providing a systematic exposition, but rather by resisting any possible objections of reason.