Or Adonai (Hebrew: אור אֲדֹנָי), The Light of the Lord, is the primary work of Rabbi Hasdai Crescas (c. 1340 - 1410/1411), a Jewish philosopher. As some Jews prefer to not use even the respectful title Adonai (Lord) other than in prayer (see names of God in Judaism), the book is sometimes called Or Hashem (אור השם) in verbal usage to avoid mentioning even this title of God directly. A partial translation of Crescas was produced by Harry Austryn Wolfson of Harvard University in 1929. Purpose of the work In the early medieval era there had been a tendency for some Jewish religious rationalists to reinterpret classical Jewish theology in the light of then-current philosophy, specifically neo-Aristotelian rationalism. This was the program of Jewish rationalist philosophers such as Saadia Gaon, Maimonides (who was influenced by Ibn Sina aka Avicenna), and Gersonides (who was influenced by Ibn Roshd, aka Averroes). In the view of Crescas, this point of view often led to mistaken conclusions, and threatened to blur the distinctiveness of the Jewish faith. He felt that this program reduced the doctrinal contents of Judaism to a surrogate of Aristotelian concepts. Crescas makes no concealment of his purpose to vindicate classical Jewish thinking against the rationalism of Maimonides and Gersonides. Of these two the former especially had endeavored to harmonize revelation and faith with philosophy. While, in those instances where this harmony could not be established, Maimonides refused to follow Aristotle to the exclusion of Moses, his successors seemed bent upon the opposite course. For them philosophical rationalism was superior to classical religious thinking. Crescas met the medieval rationalists as a philosopher who recognized the right of philosophical speculation. He did not agree with those Christian and Muslim theologians who in their speculations were advocates of a twofold truth, one for the theologian and the other for the philosopher, the former not cognizable by natural man, because supernatural and irrational, the latter open to the intelligence of natural man. Crescas attempted to show that Aristotelian rationalism was far from infallible. In this, he is a precursor of Baruch Spinoza. Crescas deplores the fact that Maimonides, whose scholarship and honesty he otherwise admires, seemed to make Greek philosophy the basis for Jewish doctrine. After attempting to show the untenability of the Aristotelian propositions, Crescas attempted to "establish the roots and the cornerstones upon which the Torah (i.e. Jewish religion) is propped, and