Spinozism

The claim

One infinite substance, God or Nature, of which thought and extension are two attributes among infinitely many. Everything follows from its nature with the necessity of a mathematical consequence.

What it held

Spinoza accepts Descartes' definition of substance — what exists in itself and is conceived through itself — and shows that it entails there can only be one. If two substances shared an attribute they would be indistinguishable; if they shared nothing they could not interact. So there is one, and everything else is a mode of it.

Mind and body then stop being two things that must be joined. They are one thing under two descriptions, which dissolves the interaction problem rather than solving it.

The ethics follows from the metaphysics with no gap. Emotions are not faults but natural events with causes, to be understood rather than deplored. An emotion ceases to be a passion as soon as we form a clear idea of it. Freedom is not exemption from causation, which is incoherent, but acting from your own nature rather than being pushed by external things.

The political work argues, in 1670, for freedom of thought and speech on the grounds that a state which tries to control opinion produces hypocrites and instability. He published it anonymously and it was banned anyway.

How it argued

Geometrical order — definitions, axioms, propositions, demonstrations — applied to God, mind and the emotions, on the view that ethics can be done more geometrico.

What it was arguing against

Descartes' dualism and his free will; the anthropomorphic God of scripture, and the idea that nature acts for purposes.

Where it disagreed with itself

Whether Spinoza is an atheist calling nature God or a religious thinker of an unusual kind. The parallelism of thought and extension, and how it avoids being two things after all.

Common misconceptions

That determinism makes his ethics pointless. Understanding is itself a cause, on his account, so knowing why you feel something changes what happens next. And he is not a pantheist in the loose sense — God is not identical with the totality of things but is the substance of which they are modes.

How it began

Expelled from the Amsterdam Jewish community at twenty-three, in terms of unusual severity, and never joined another. He ground lenses and declined a professorship.

What became of it

A byword for atheism for a century, then revived by Lessing, Goethe and the German Romantics, and now one of the most active areas in the history of philosophy.

Lasting influence

German idealism, through the pantheism controversy. Marx, Freud and Einstein all acknowledged him. Deleuze called him the prince of philosophers.

Why it still matters

Contemporary work on emotion, on freedom without libertarian free will, and on mind as identical to body under another description all keep returning to him.

Put another way

A theorem, in which nothing could have been otherwise and understanding is the only freedom available.

Where to start

Part III of the Ethics, on the emotions. It stands alone and it is the most immediately gripping section.

The surprising bit

The Ethics was published after his death by friends who left his name off the title page. He had withheld it for years, having watched what happened to a friend who published less.

In their own words

Connections

Answers

Cartesianism, Jewish Aristotelianism

Opposed by

Cartesianism

Influenced

German Idealism, Lebensphilosophie

The verdict

The most rigorous metaphysical system in European philosophy, written by a man who refused every position that might have compromised it.

Sources

• Stanford Encyclopedia of Philosophy