Baruch Spinoza
God, that is, Nature: everything follows by necessity.
Baruch Spinoza (1632 – 1677, Dutch Republic (Netherlands)) : rationalism. There is only one reality, infinite, which Spinoza calls "God or Nature". Everything that exists is in it and follows from it by necessity, as the properties of a triangle follow from its definition. On AskPhilosophy: 6 reconstructed arguments, 5 quotes checked word for word against the original texts, and 3 common beliefs examined; every text carries an authenticity badge (written by the author, posthumous, student notes, reported, apocryphal).
Why he matters
One of the most radical thinkers in history: a God who is not a person, a historical reading of the Bible, an early defence of free speech and democracy. Accused of atheism for a century, he was later admired by Goethe, Hegel, Nietzsche and Einstein.
His times
Born into the Portuguese Jewish community of Amsterdam, he was expelled from it in 1656, aged 23. He lived modestly grinding optical lenses and turned down a chair at Heidelberg to keep his freedom. He published his Theological-Political Treatise without his name (1670); the Ethics appeared only after his death.
His positions
click a row to see the evidenceHe sets out to prove that God necessarily exists, but this God is Nature itself: no will, no plan, no personal love for us. Neither classical theism nor atheism: it is the axis's "impersonal God" position. His contemporaries accused him of atheism; he rejected the charge.
A rationalist: the Ethics is demonstrated "in geometrical order", with definitions, axioms and propositions. Truth reveals itself, like light.
A true idea carries its own certainty. He writes: I do not claim to have the best philosophy, but I know I understand the true one, as one knows a triangle's angles equal two right angles.
Neither dualist nor materialist: mind and body are one and the same thing seen in two ways (thought and extension). The mind does not act on the body, nor the body on the mind: they go together.
No free will: every volition is determined by a cause, itself determined by another, to infinity. We think we are free because we do not know the causes of our desires. But he keeps a meaning for the word freedom: acting from the necessity of one's own nature, by understanding (a "free necessity"). This is close to what is now called compatibilism, hence a position between the two poles.
Good and bad are nothing in things themselves: they are ways of comparing. We do not desire a thing because it is good; we judge it good because we desire it. Yet what is truly useful to our nature can be known with certainty.
He separates the domains: reason seeks truth, faith teaches only obedience and charity. Theology must not serve reason, nor reason theology. But on truth and falsehood, reason alone judges.
Nature acts for no end: the world has no purpose set in advance. But there is a true good open to all: understanding, and the joy it brings ("blessedness").
Humans are always subject to passions and rarely guided by reason. But they are neither wicked nor corrupt: they are part of Nature, and living by reason, "man is a God to man".
The end of the state is freedom. Democracy is the most natural regime. Everyone must be able to think and say what they think, while obeying the laws in their actions.
An ethics of power and joy: virtue is acting, living and preserving one's being under the guidance of reason. Happiness is not the reward of virtue, it is virtue itself.