Jewish Aristotelianism

The claim

Philosophy and Torah are compatible, and where they appear not to be, the philosophy is usually right about the argument and the text about the conclusion — but not always, and the exceptions are where the interesting work happens.

What it held

After Maimonides, Jewish philosophy in Provence and Spain was Aristotelian by default, largely reading Aristotle through Averroes. Most of it is commentary. Two figures are not.

Gersonides is the most radical. Where Maimonides insisted on negative attributes, Gersonides argued for positive knowledge of God by analogy. And on divine foreknowledge he followed the argument to a conclusion nobody else would accept: God knows all that is determinate, but future free acts are not determinate, so God does not know them. He also wrote on astronomy, invented an instrument used by navigators for centuries, and produced original work on mathematical induction.

Hasdai Crescas went the other way and attacked the whole framework. His Light of the Lord dismantles Aristotle's arguments against the vacuum and against actual infinity, positions that had to be abandoned before modern physics could begin. Spinoza read him, and the traces are visible.

What closes the tradition is not refutation but 1492.

How it argued

Commentary on Averroes' commentaries, plus independent treatises where the tradition's conclusions were found unacceptable.

What it was arguing against

Maimonides on divine attributes, in Gersonides' case; and Aristotle's physics entirely, in Crescas'.

Where it disagreed with itself

Whether Gersonides' limitation of God's knowledge is defensible — most of the tradition thought not, and his book was nicknamed Wars Against the Lord. Whether philosophy had weakened Jewish communities before the expulsions, which was argued bitterly afterwards.

Common misconceptions

That it is derivative. Crescas' attack on Aristotelian physics anticipates arguments that had to be made again in the seventeenth century, and Gersonides' astronomy was based on his own observations.

How it began

Hebrew translations of Arabic philosophy made in Provence, which put the whole falsafa tradition into the hands of readers who had no Arabic.

What became of it

Ended by expulsion — from Spain in 1492 and Portugal in 1497 — rather than by argument.

Lasting influence

Crescas on Spinoza, demonstrably. Gersonides' astronomical instrument, the Jacob's staff, was in use at sea for four hundred years.

Why it still matters

The foreknowledge problem — whether God's knowing what you will do makes it unfree — is unresolved, and Gersonides' answer remains one of the live options.

Put another way

A workshop where the tools are borrowed and two of the workmen redesign them.

Where to start

Crescas on the vacuum and the infinite, in a modern edition with the physics explained.

The surprising bit

Gersonides has a crater on the moon named after him for astronomical work he did with instruments he built, while writing a commentary on the Torah.

In their own words

Connections

Answers

Maimonideanism, Averroism

Influenced

Spinozism

The verdict

A tradition remembered as commentary that contains two of the most original arguments of the fourteenth century.

Sources

• Stanford Encyclopedia of Philosophy