MAIMONIDES PRESUPPOSES that to be a Jew and to be a philosopher are incompatible with one another? Nevertheless, a Jew can use philosophy to supplement and refine the tradition. Maimonides wrote two works on De'ot and Eight Chapters, both of which are part of much larger works on law, and both contain Aristotelian elements. De'ot is written in Hebrew, while Eight Chapters, like the Guide o / t h e Perplexed, is in Arabic. 2 The language of DePot is of special interest because the Hebrew language had not yet developed a philosophic terminology. De'ot indicates, directly as well as indirectly, some of the terms indigenous to Jewish ethics. Its language also reveals certain important differences between the philosophic and traditions. Inherent in De'ot is the problem of transforming basic concepts from one language to a radically different language. Rabbinic Hebrew has no words which translate literally such key terms in Aristotle's ethics as virtue, happiness, nature, passion, or even ethics, a Within the limitations of rabbinic Hebrew, Maimonides conveys these concepts with sufficient precision for the practical purpose of De'ot. The fact that he studied the Aristotelian corpus in the Arabic language rather than in Greek does not alter significantly the problem he had to face, for by his time Arabic had a fully developed philosophic terminology corresponding to Greek usage. De'ot shows how small a portion of the terminology in Aristotle's Ethics is