GERSONIDE (Ralph = Rabbé Lèwì ben Gerson). — Jewish philosopher, mathematician, astronomer, and biblical commentator, born in 1288 at Bagnols (southern France), died on 20 April 1344, also known as Léo de Balneolis or Léon de Bagnols, Léo Hebræus, and Maestro Leon.
As a philosopher, G. interprets the Aristotelian system in the exposition of Averroes and is the author of the work *Milhamoth 'Adhônaj* ("The Wars of the Lord," a title which, given G.'s rationalism, one of his critics explains as "The Wars against the Lord"). Unlike Saadiah, Maimonides, and Albo, G. does not aim to present a complete system of Judaism but addresses individual problems, particularly the human intellect in the light of Aristotelian thought as expounded by Alexander of Aphrodisias and Themistius, Avicenna, and Averroes.
The material intellect is not a substance but merely a disposition, a potentiality for receiving ideas. The active intellect is not a faculty of the human soul but an emanation of the "separated intelligences," specifically the motor of the lunar sphere. The material intellect abstracts from the images of the imagination their conceptual essence and thereby becomes intellect in act. The active intellect contributes to this transformation. Only the rational part of the soul is immortal. The beatitude of man after death depends on the degree of theoretical knowledge he has acquired in life. Beatitude in the hereafter consists in contemplation devoid of any further enrichment by new knowledge.
In keeping with the spirit of the age, G. attaches importance to dream visions of divinatory value and determines their significance from the positions and movements of the celestial bodies.
To this category of phenomena belongs prophecy. Errors in prediction by prophets, astrologers, and diviners are due to imperfections in astronomical observations, the intervention of acts of free will, or chance. Wisdom and the use of freedom enable man to shape his own destiny. In prophecy, the active intellect acts directly upon the material intellect. In dream visions and divination, it acts upon the imagination and only through it upon the intellect. In this way, G. excludes divine inspiration from prophecy.
Divine omniscience does not extend to particulars, for particularity is proper only to materiality. The just God does not know particulars, and hence the injustices observed in life.
Accidental occurrences and acts of free will do not fall within the scope of divine foreknowledge, and thus divine Providence does not extend to particulars. Individual divine Providence consists in man's proper use of his intelligence and his intellectual and moral gifts. Misfortune would signify intellectual decline. G. considers Aristotle's opinion on the eternity of the world to be erroneous.
The ideas contained in *The Wars* are reflected in his biblical commentaries. The Bible is a guide to intellectual—most importantly—and moral perfection. Biblical cosmogony is for him the foundation of physiological physics. Water is divided into the four elements and the fifth essence; thus it is matter that exists *ab aeterno*. The Bible legislates, hence man is endowed with free will. God foretells future events, hence man's fate is determined through the natural order. With the aid of his own prudence, man can escape destiny; hence the statement: "God repented."