Medieval philosopher followed the rationalistic mode of Aristotle.
Reprinted from The Jewish Religion: A Companion, published by Oxford University Press.
Gersonides or Levi ben Gershom (1288-1344) of Provence, was a Talmudist, philosopher, and astronomer. Gersonides wrote a lengthy commentary on the Bible in which his general methodology is to give a list of "advantages" to be gained from the biblical narratives, that is, the moral lessons to be derived from them.
His philosophical approach in this work and particularly in his Wars of the Lord follows the rationalistic mode of Aristotelian philosophy in its Arabic garb. He understands, for instance, the fall of the walls of Jericho (Joshua 6) to have been caused by the weakening of the walls by the tramping feet of the priests and the blowing of the trumpets. According to Gersonides, the sun did not stop for Joshua (Joshua 10:12-14) but only appeared to do so because the battle was over so soon.
Similarly, the shadow on the sundial did move 10 degrees backwards (2 Kings 20:11), though not because the sun really moved but as a result of the arrangement of the clouds at the time. In all this Gersonides' principle is that the Torah does not oblige us to accept things that are contrary to reason.
In his Wars of the Lord, Gersonides understands the doctrine of creation as meaning not that God created the world "out of nothing" but rather that he created it out of a formless substance. On the problem of free will and divine foreknowledge, Gersonides advances the startling theory that God knows beforehand only the possibilities open to a man but, since man is free to choose, not the actual choice he will make.
These views seemed so startling to later theologians that they dubbed his work heretical, calling it "The Wars against the Lord." It is noteworthy, however, that Gersonides' works became acceptable even to Orthodox Jews as representing the rationalistic tendency in Jewish thought, which has a legitimacy of its own.