 Strauss argues, both in his early work on medieval Jewish rationalism and in his mature American work, that only revelation, and not philosophy, can provide the basis of a universal morality. To be sure, this universal morality is based on faith and not certain knowledge. Nevertheless, it does underscore a moral weakness in the philosophical position. Nowhere does Strauss highlight this point more than in his seminal 1943 essay on the medieval Jewish thinker Judah Halevi. This essay became an integral part of Persecution and the Art of Writing and far from an obscure relic of an interest in things Jewish and medieval, Strauss’s reference to this essay forms a decisive part of his argument in Natural Right and History.