Early Jewish philosophy was heavilly influenced by the philosophy of Plato, Aristotle and Islamic philosophy. Many early medieval Jewish philosophers (700s to 1000 CE) were especially influenced by the Islamic Motazilites; they denied all limiting attributes of God and were champions of God's unity and justice).
Over time Aristotle came to be thought of as the philosopher par excellence among Jewish thinkers thinkers. This tendency toward Aristotle was no less marked in the Islamic, the Christian Byzantine and the Latin-Christian schools of thought.
A schismatic break-off from rabbinic Judaism, Karaism, developed its own form of philosophy, a Karaite version of the Islamic Kalâm. Early Karaites based their philosophy on the Islamic Motazilite Kalâm; some later Karaites, such as Aaron ben Elijah of Nicomedia (fourteenth century), reverts, in his Etz Hayyim (Hebrew, "Tree of Life") to the views of Aristotle.
The Jewish poet—philosopher Solomon ibn Gabirol (died about 1070 CE) was influenced by Plato. In Gabirol's work Plato is the only philosopher referred to by name. Characteristic of the philosophy of both is the conception of a Middle Being between God and the world, between species and individual. Aristotle had already formulated the objection to the Platonic theory of ideas, that it lacked an intermediary or third being between God and the universe, between form and matter. This "third man," this link between incorporeal substances (ideas) and idealess bodies (matter), is, with Philo, the "Logos"; with Gabirol it is the divine will. Philo gives the problem an intellectual aspect; while Gabirol conceives it as a matter of volition, approximating thus to such modern thinkers as Schopenhauer and Wundt.
Gabirol's philosophy made little impression on Judaism. Among Jews he is esteemed as a poet; while Christian scholasticism, in the persons of its two chief representatives, Albertus Magnus and his pupil, Thomas Aquinas, defers to him quite as frequently and gratefully.
A separate entry exists for Kabbalah. A fundamental difference between the Kabbalists and exponents of philosophy is due to their different views of the power of human reason. Kabbalists reject the conclusions of reason, and rely upon tradition, inspiration, and intuition. Philosophers, on the other hand, hold that reason is a prior requisite for all perception and knowledge.
Saadia Gaon (892-942 CE) in his Emunot Ve-Deot ("Principles of Faith and Knowledge") posits the rationality of the Jewish faith, with the restriction that reason must capitulate wherever it contradicts tradition. Dogma must take precedence of reason. Thus in the question concerning the eternity of the world, reason teaches since Aristotle, that the world is without beginning; that it was not created; in contrast, Jewish dogma asserts a creation out of nothing. Since the time of Aristotle it was held that logical reasoning could only prove the existence of a general form of immortality, and that no form of individual immortality could exist. Mainstream Jewish dogma, in contrast, maintained the immortality of the individual. Reason, therefore, must give way in Saadia's view.
The Jewish poet-philosopher Yehuda Halevi (twelfth century) in his polemical work Kuzari made strenuous arguments against philosophy. He became thus the Jewish Al-gazali, whose "Destructio Philosophorum" was the model for the Kuzari.
Human reason does not count for much with him; inward illumination, emotional vision, is everything. The Kuzari describes representatives of different religions and of philosophy disputing before the king of the Khazars concerning the respective merits of the systems they stand for, the palm of course being ultimately awarded to Judaism.
Judah ha-Levi could not bar the progress of Aristotelianism among the Arabic-writing Jews. As among the Arabs, Ibn Sina and Ibn Roshd leaned more and more on Aristotle, so among the Jews did Abraham ibn Daud and Maimonides.
Rabbi Levi ben Gershon, also known as Gersonides, of the Ralbag, (1288-1345) is best known for his work Milhamot Adonai, (Wars of the Lord). Among scholastics, Gersonides was perhaps the most advanced; he placed reason above tradition.
Hasdai Crescas (1340-1410) is best known for his Or Adonai (Light of the Lord) is one of the most original and independent works of scholasticism in general. Apart from its hardihood in openly and unreservedly attacking Maimonides' claims of infallibility for Aristotle in all matters pertaining to the sublunary world, it has the merit of projecting the problem of causes into the very foreground of philosophical thought. The mental heights of Crescas were by no means maintained by his pupil Joseph Albo, the last Jewish scholastic in the Spanish peninsula. In his '"Iḳḳarim" (Fundamental Doctrines) he sinks to the level of an ordinary philosophizing rhetorician and moralist. It is difficult perhaps to penetrate the depth of thought and deft language of Crescas; but it is just as difficult to work one's way through the pitiful shallows of Albo's unctuous commonplaces. These lastnamed philosophers wrote in Hebrew, and therefore can hardly be reckoned among Arabic-Jewish philosophers. The chief representative of Arabic-Jewish scholasticism, Maimonides, must now receive attention.
Maimonides holds tenaciously, as against Aristotle, to the doctrine of creation out of nothing. God is not only the prime mover, the original form, as with Aristotle, but is as well the creator of matter. Herein Maimonides approaches more closely the Platonic "Timæus" than the Stagirite. Of God, the All-One, no positive attributes can be predicated. The number of His attributes would seem to prejudice the unity of God. In order to preserve this doctrine undiminished, all anthropomorphic attributes,such as existence, life, power, will, knowledge, —the usual positive attributes of God in the Kalâm —must be avoided in speaking of Him. Between the attributes of God and those of man there is no other similarity than one of words (homonymy), no similarity of essence ("Moreh," i. 35, 56). The negative attributes imply that nothing can be known concerning the true being of God, which is what Maimonides really means. Just as Kant declares the Thing-in-itself to be unknowable, so Maimonides declares that of God it can only be said that He is, not what He is.
Finally, it may be stated that in the question of universals—the chief problem of scholasticism—Maimonides takes strict Aristotelian ground ("Moreh," i. 51, iii. 18; treatise on "Logic," ch. 10), in so far as he denies reality to the human species, but admits its true essence to exist only in the individual (according to the formula "Universalia in re"). In his "Ethics" (as systematized by D. Rosin, 1876) he follows the Stagirite in consistently insisting upon the "fitting mean" (μεδóτης) as well as in the elevation of the intellectual virtues over the ethical. Thus, the Arabic-Jewish philosophy presents the same endeavor as the contemporary Arabian, Byzantine, and Latin-Christian scholasticism, namely, to bring about from the standpoint of the knowledge of the day a reconciliation between religion and science.
However insignificant, compared with the fund of our present knowledge, this Arabic-Jewish philosophy may appear in its attitude toward the various problems and their solutions, two things must not be overlooked. In the first place, modern pride of culture should not prevent the confession that not a single step taken since the days of Maimonides has brought the solution of such problems any nearer. And, in the second place, it must not be forgotten that the scholastics preserved the continuity of philosophical thought. Without the activity of these Arabic-Jewish philosophers, especially of those Jewish translators of whose work Steinschneider has treated so exhaustively, the mental culture of the Western world could scarcely have taken the direction it has, and certainly not at the rapid rate which was made possible through the agency of the Humanists and of the Renaissance. The Arabic-Jewish philosophers were the Humanists, the agents of culture, of the Middle Ages. They established and maintained the bond of union between the Arabic philosophers, physicians, and poets on the one hand, and the Latin-Christian world on the other. Gabirol, Maimonides, and Crescas are of eminent importance in the continuity of philosophy, for they not only illumined those giants of Christian scholasticism, Albertus Magnus and Thomas Aquinas, but their light has penetrated deeply into the philosophy of modern times. Leibniz speaks with no little respect of Maimonides, as does Spinoza of Crescas. Moses Mendelssohn and Solomon Maimon, the two Jewish friends of Immanuel Kant, took their point of departure from the Arabic-Jewish philosophy, as Baruch Spinoza had done. Sufficiently indicative of the bond of intellectual continuity is the fact that the same Solomon Maimon, who assumed the name Maimon simply out of reverence for Maimonides, was gratefully described by Kant in a letter to Marcus Herz as the critic who understood him best, and who had penetrated most deeply into his "Critique of Pure Reason."
Baruch Spinoza
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Elliot N. Dorff, Neil Gillman, Abraham Joshua Heschel, Joseph Soloveitchik
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See also: Judaism, Jewish principles of faithKaraite philosophy
Avicebron, Solomon ibn Gabirol
Jewish Mysticism, Kabbalah
Saadia Gaon
The anti-philosophy of the Kuzari
The rise of Aristotelian thought
Maimonides
Position in the History of Thought
Post-Enlightenment Jewish philosophers
Modern Jewish philosophers