||R. Gershon b. Solomon of Arles (late 13th century), Provencal scholar. There is almost no exact information about his life. The period in which he lived is estimated from the sources he used for his book Sha'ar ha-Shamayim (The Gate of Heaven), the only work by him which is extant, and probably the only one he wrote. It has been estimated that this work was written between 1242 and 1300. It is now agreed that R. Gershon lived in Arles in southern France (Provence). The traditional notion that he lived in Catalonia is shown to be incorrect by his own words: "For in the area of Catalonia the sheep and goats are smaller than those in our area" (Sha'ar ha-Shamayim (Roedelheim, 1801), 30b, 26–27). Spain is also not his place of residence: "One in our provinces and one in the provinces of Spain" (ibid., 20a, 4). It also appears that Gershon regarded France as outside his homeland (ibid., 16a, 11). Sha'ar ha-Shamayim is a brief popular summary of the natural sciences, astronomy, and theology of Gershon's day. It is divided into three parts: natural sciences, theology, and astronomy. The first part contains ten treatises, on the following subjects: the four elements (including a discussion of meteorology); inanimate objects; plants; animals; fowls; bees, ants, and spiders; fish; man; parts of the body; sleeping and waking (including a discussion on dreams). The chapters on man include also psychological data, the law of heredity, and even clinical prognoses. The first part is the longest and most detailed. In the extant editions of the work it takes up five-sixths of the entire book, but in some manuscripts there are obvious additions, which are not found in the printed version.
Gershon lists a great number of Greek, Latin, Arabic, and Jewish authors, and cites from their works. Among the authors cited by him are Homer, Plato, Pythagoras, Aristotle, Galen, Hippocrates, Al-Farabi, Avicenna, and Averroes. It appears that he received this knowledge from Hebrew translations of earlier scientific and philosophic literature rather than from original sources. He states in his introduction that he had "some of the books of the philosophers which had been translated from their languages to his own." He further states, with regard to the second and third parts of the book, that he based himself primarily on those writings of Maimonides and the Arabic scholar Al-Farghani (ninth century), which suited his purposes. It is not known which direct sources were used for the first part of the book.
In addition to citing from written sources, R. Gershon also set down what he had heard through reports from Jews or Christians. He was not an independent thinker; even where he makes statements in the first person, these are often taken literally from other sources. Because there were not enough adequate words in Hebrew, and perhaps also in order to make for easier understanding, Gershon expressed many scientific concepts and objects by their foreign names, which he probably found in his sources. These names, usually Latin or Arabic, are an integral part of the text, unlike the foreign usages in other medieval writings, such as the commentaries of Rashi, whose purpose in using foreign words is merely to clarify the meaning of difficult Hebrew terms. Sha'ar ha-Shamayim served for hundreds of years as a popular book of sciences for readers of Hebrew. It was widely circulated and is extant in many manuscripts. The extant editions are all imperfect and incomplete in comparison with a few of the manuscripts. The first edition (Venice, 1547) apparently served as a basis for all subsequent editions (Roedelheim, 1801; Zolkiew, 1805; Warsaw, 1876; Jerusalem, 1944), in which corrections were made only on the basis of conjecture.