Gersonides, or Levi ben Gershon, also known by his acronym, "RaLBaG," was a French Jewish philosopher, biblical exegete, mathematician, and astronomer. He was born at Bagnols and died at Perpignan. He was the inventor of two astronomical instruments, the Jacob's staff ("baculus") and an improved camera obscura. Gersonides' literary contributions include biblical commentaries of a philosophical and moral tone, supercommentaries to Averroes's treatises on Aristotle, and his philosophical masterwork, Milhamot Adonai (Wars of the lord). Because of his knowledge of Averroes, Gersonides was exposed to a more authentic version of Aristotle than was available to his predecessors and was thus motivated to reexamine certain problems that he felt had previously been treated inadequately or incorrectly. These problems, corresponding to the six sections of the "Wars," are (1) the nature and immortality of the soul, (2) prophecy, (3) the nature of God's knowledge, (4) divine providence, (5) miracles and the structure of the universe, and (6) the creation of the world. Methodologically, he recognized the authority of the four roots of knowledge (as first formulated by Saadya Gaon), namely, reason, sensory perception, divine revelation, and rabbinic tradition, in that order of priority, although he seldom cited the last specifically.
The work begins with a detailed analysis of Aristotle's doctrine of the soul according to the interpretations of Alexander of Aphrodisias, Themistius, and Averroes. In agreement with Alexander, Gersonides maintained that the material or hylic intellect is a capacity inherent in the sensitive soul. Under the agency of the Active Intellect, the last of the separate intelligences, the material intellect is transformed, through the acquisition of ideas, into an actual or acquired intellect. Opposing the nominalism of Alexander and Maimonides, Gersonides maintained the reality of the ideational content of the acquired intellect. It is this acquired intellect that survives independently after the death of the individual.
Gersonides' account of the nature of God's knowledge is related to his theory of divine attributes. Maimonides' theory of homonymy, according to which attributes in general and the term knowing in particular refer to entirely different concepts when applied to God and man, allowed Maimonides to maintain both God's absolute omniscience and human free will. Rejecting this as absurd, Gersonides reaffirmed, in agreement with the Muslim philosophers Avicenna and Averroes, that attributes are to be treated as ambiguous terms, applied in a primary sense to God but in a derivative sense to man. Furthermore, the attributes imply no plurality in God's nature since they are subjects of discourse and not of essence, just as the terms redness and color imply no plurality in the concept "red."
Since God's knowledge is similar in nature to man's, he cannot know the contingent and consequently knows the particulars only insofar as they are ordered. This amounts to a virtual restriction of divine knowledge to the universals. Since men are endowed with free will, this restriction normally precludes special providence for individuals. However, some individuals enjoy special providence; this consists in a knowledge, received from the Active Intellect, of stellar configurations that determine events on earth. Modern scholarship has not generally noted that this explanation of special providence for the intellectual elite was foreshadowed in one of the two discussions of the problem in Maimonides' Guide for the Perplexed (III.51).
The communication of astrological information to the human intellect by the Active Intellect is known as prophecy. The prophet, to the extent of his ability, interprets the general information received, in the light of the particular circumstances with which he is concerned, Gersonides' tendency to deny God's direct involvement in terrestrial affairs is further illustrated by his theory that the capacity for miracles was implanted in nature so that miracles do not represent any specific divine concern.
In his discussion of the origin of the world, Gersonides agreed with Maimonides that it was indeed created but, in opposition to him, maintained that ex nihilo nihil fit. Rather, he posited an absolutely formless matter (not eternal in time since time did not exist before the creation of the world) out of which the world was formed. Gersonides found this dualism useful in ascribing the origin of evil to matter.
Gersonides' Milhamot Adonai (Wars of the lord) was first printed at Riva di Trenta (1560) and reprinted at Leipzig (1866). The editions omit the rather technical astronomical treatise in the fifth book which is extant in manuscript and which was translated into Latin by order of Clement VI. The partial German translation by Benzion Kellerman, Die Kämpfe Gottes von Lewi ben Gerson (Berlin, 1914), should be read in conjunction with Isaac Husik's review, "Studies in Gersonides," in Jewish Quarterly Review, n.s., 8 (1917–1918): 113ff. and 231ff. For a complete bibliography, see Encyclopedia Judaica (Berlin, 1929), Vol. IV, p. 656; Vol. VII, pp. 328ff. and 338, to which may be added H. Wolfson, "Maimonides and Gersonides on Divine Attributes as Ambiguous Terms," in Mordecai Kaplan Jubilee Volume, edited by M. Davis, 515–530. (New York: Jewish Theological Society, 1953).
Frank Talmage (1967)
"Gersonides (1288–1344)." Encyclopedia of Philosophy. . Encyclopedia.com. (July 26, 2017). http://www.encyclopedia.com/humanities/encyclopedias-almanacs-transcripts-and-maps/gersonides-1288-1344
"Gersonides (1288–1344)." Encyclopedia of Philosophy. . Retrieved July 26, 2017 from Encyclopedia.com: http://www.encyclopedia.com/humanities/encyclopedias-almanacs-transcripts-and-maps/gersonides-1288-1344
Gersonides (gərsŏn´Ĭdēz) or Levi ben Gershon (lē´vī bĕn gûr´shən), 1288–1344, Jewish philosopher, astronomer, and mathematician, called also Ralbag, from the initials of his Hebrew name, b. Languedoc. He wrote scientific works and commentaries on Averroës and the Torah. His Milchamoth Adonai [the wars of the Lord] is an elaborate treatise modeled after the Moreh Nevukhim of Maimonides. It is mainly a systematic criticism of the syncretism of Maimonides. His scientific views remained influential into the 19th cent.
"Gersonides." The Columbia Encyclopedia, 6th ed.. . Encyclopedia.com. (July 26, 2017). http://www.encyclopedia.com/reference/encyclopedias-almanacs-transcripts-and-maps/gersonides
"Gersonides." The Columbia Encyclopedia, 6th ed.. . Retrieved July 26, 2017 from Encyclopedia.com: http://www.encyclopedia.com/reference/encyclopedias-almanacs-transcripts-and-maps/gersonides