Patai resolves the difficult questions of what a Jew and what a ""group mind"" are by defining the first as ""a person who considers himself a Jew and is so considered by others"" and the second as the sum of shared mental traits, beliefs, and values. In this sympathetic but ultimately unsuccessful study, Patai (author also of The Arab Mind), summons an impressive amount of scholarship to locate six historical encounters in a span of three millenia which, he argues, have crucially shaped ""the essence of Jewishness."" He begins with the Biblical Jews and the Canaanite culture, from which the Jews ""acquired practically the entire gamut of (their) civilization,"" including the Hebrew language. Here the Jews were transformed from a nomadic to a ""settled, agricultural"" people; and here for the last time they were tempted by polytheism. Patai proceeds through Hellenism, where exposure to ""Greek Wisdom,"" e.g. Homer, expanded an intellectual outlook hitherto limited largely to the Talmud. The ""Arab Golden Age,"" which produced both Maimonides (""one of the two greatest creative minds in the medieval world"") and the Jews' first significant interest in the sciences. Renaissance Italy; Eastern Europe, whence emerged Hasidism. And finally the Enlightenment of Western Europe, whose 200 years Patai captions ""Triumph and Tragedy."" Here are the seeds of intellectual prodigality (of Marx, Freud, and Einstein); here, too, the first weakening of Jewish identity, of that solidity which had been its core, ""unaltered, undiluted,"" and with it the emergence of ambivalence, neuroses, and occasionally self-hate. But as convincing as Patai's purview of Jewish cultural-intellectual history is, he is equally bland in the second haft of his book which raises the problems of Jewish intelligence, giftedness, and genius; the phenomenology of the Jewish character and personality; questions of their mental and physical health; the inspiration of their disproportionately great contribution to culture, etc.' Neither will his information be new to those interegted in such matters, nor does he synthesize extant data creatively to advance arresting hypotheses. The net effect of these chapters is rather of an a posteriori attempt to justify his audacious title.