(Levi Ben Gerson, 1288 - 1344)

Otherwise known as Gersonides, he was the most famous Jewish follower of Aristotle apart from Maimonides.


It's quite hard to piece together his life, as Gersonides left few letters and didn't talk about himself at all in his works. Nor was he written about by his contemporaries, so we're left to rely on inference, and prevailing historical conditions to give us an outline of his life. We do know he was born in 1288 in Provence, likely to Gershom ben Salomon de Beziers, a notable man mentioned in medieval records (but we don't know this for sure). In any case he seems to have had a decent education and upbringing, free from any severe trauma that impacted his later works.


At this point in time, Islam was in control of Spain, and not as closely integrated with society as it would be later, so there was a general migration of Jews into France from that region. Indirectly, as a result of this Provence became a cultural center for Jewish intellectual activity. The authorities there had a lenient view of Judaism, and thus the Jewish scholars took advantage of this unique good favour to pursue their creative urges, especially in philosophy and theology. While there wasn't direct access to the works of Aristotle, his work was avilable through the 100 year old commentaries written by Averroes, a Spanish Muslim philosopher. Work began on these, and gradually by the turn of the fourteenth century, they had been translated into Hebrew. It is likely then that Gersonides got his Aristotle from this source, via the wisdom of Averroes.


Although Gersonides would have had to have spoken the local dialect of the region, his entire cannon of work is in Hebrew, including quotes and references. By all accounts he had an apparently ordinary life for a Jewish person, getting married to a distant cousin, taking part in the money lending business, and staying in his region. He was a respectable person, with a decent income. His philosophic project was to integrate Aristotle with the teachings of the Jewish faith, in a parallel fashion to the preceding Christian attempts at assimilation. As such he drew heavily upon, and revised, and tightened up the works of Maimonides, attempting in all cases to stick more closely to the Aristotlean vision than Maimonides did.


What separates, and in some cases elevates Gersonides above his contemporaries, and indeed Maimonides is his incredible skill with mathematics, which combined with his empirical stance, and need for verification, makes him a precursor of those who used the scientific method. An example of this is found in his building and acquiring of telescopes and taking measurements of the stars and planets, and comparing them against the undisputed kind of astronomy at the time Ptolemy, and his subsequent rejection of Ptolemy's law of Planetary motion.

"no argument can nullify the reality that is perceived by the senses, for true opinion must follow reality but reality need not conform to opinion"-(Goldstein, 1974, p. 24).

"We did not find among our predecessors from Ptolemy to the present day observations that are helpful for this investigation except our own"-(Wars, V.1.3, p. 27),

Gersonides' scientific works are mainly in mathematics and astronomy though, his Sefer Ma'aseh Hoshev (The Work of a Counter, 1321) is about arithmetical operations and uses of a symbolic notation for numerical variables. But while his maths was excellent and innovative, as mentioned above he shone at his best in astronomy. His astronomical writings are contained mostly in book 5, part 1 of Milhamot Ha-Shem. He criticized astronomical theories of the day, shows astronomical tables, and describes astronomical inventions. He constructed one to measure the height of stars from the horizon. The astronomical parts of Milhamot Ha-Shem were translated into Latin during his lifetime. One of the craters of the moon, Rabbi Levi, is named after him.


Gersonides was also well known as a Halakhist, one who deals with the intricacies of Jewish law. Judaism is (or least was then) composed of rituals and procedures that had to be performed in order please Jehovah, and the complex interpretations of the Torah, the commentaries, and many other sources of authority lent a certain difficulty in determining which course of action to pursue. His greatest contribution was in the area of biblical commentary. The commentary on Book of Job, completed in 1325, which complements book 4 of Milhamot Ha-Shem, is concerned with the problem of divine providence. Each of the characters in the Book of Job represents a different theory of divine providence.

As a consquence of this thirst for precision, Gersonides had little time for rhetorical or stylistic tricks in his writings. He's likened to Aquinas, or even Aristotle himself in his way of describing things using precise, technical jargon, with little reference to examples. This also contrasts with the approach of Maimonides which was much more 'reader friendly' and used metaphor, similies, and sometimes vague language to try to give a general feel for the topic, and it is clear that Gersonides has no time for this, seeing as his aim the core idea of accuracy to make the subject as clear as possible.

Gersonides died on 20 April 1344, recognized by the history books, but not revered.