The kabbalah flowered during the Middle Ages, combining older trends in Jewish mysticism with Neoplatonism and other ideas. The kabbalists retained the idea that the totality of God's nature is ultimately beyond human grasp ("Ein Sof" [Heb., literally, = without end] as the "Nothing"), yet, in keeping with tradition, held to a vision of a personal God who exists as the active, creative, and sustaining force within the cosmos ("Ein Sof" as the "Everything"). Spain was a major center of kabbalistic thought, which after the expulsions and forced conversion in 1492, spread and became more central to Jewish life in the Mediterranean world. Palestine then became the center of kabbalism, especially as it was developed by Isaac Luria and others.
A Jewish philosophy developed in answer to the questions raised by the exposure to Greek thought as distilled through the Islamic natural philosophy and metaphysics. Central to these issues was the conflict between reason and revelation: whether revelation was necessary if all could be ascertained through reason, or whether reason was imperfect and revelation was God's assisting humans to know the truth. Maimonides argued that one can say nothing positive about the personal nature of God, which is beyond human comprehension; one can only indicate what He is not (thus, the statement that God is wise says only that God is not ignorant, not how wise He actually is).
While the Jewish Middle Ages is usually defined by scholars as extending at least into the 18th cent., there was a Jewish counterpart to the general European Renaissance of the 15th and 16th cent., and figures such as Judah Abravanel were influenced by contemporary European philosophic currents. The expulsion of the Jews from Spain in 1492 led to the Jews of N Italy, S France, and the Levant coming under Sephardic influence (see Sephardim), and these events provoked much messianic and kabbalist speculation, culminating in the spectacular career of the self-proclaimed Messiah, Sabbatai Zevi.
The Amsterdam community of Marranos (those Jews forced by the Inquisition to adopt Christianity, but who continued to practice Judaism in secret, and many of whom later emigrated and returned to the Jewish fold) often provided a liberalizing influence on Orthodox Judaism, most significantly in the person of Baruch Spinoza, a Jew excommunicated for his unsparing critique of Rabbinic Judaism. The reaction to Sabbatianism and philosophical liberalism caused a hardening of rabbinic orthodoxy, but the Jewish world of the 18th cent. remained turbulent. It produced both the great traditionalist rabbinic figure Elijah ben Solomon and the untraditional figures of Baal-Shem-Tov, the founder of Hasidism (which Elijah himself fought against), and Moses Mendelssohn, the spiritual progenitor of later reformers whom Elijah's spiritual descendants repeatedly condemned.
The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2012, Columbia University Press. All rights reserved.