Benedict de Spinoza · Philosophy
Spinoza argues that there is only one substance - infinite, self-caused, and necessary - and that this single substance is what we may call either God or Nature. Everything that exists is a mode of this one reality.
Baruch (later Benedict) Spinoza, writing in the Dutch Republic in the 1660s and 1670s, set out to prove, with the rigour of geometry, a single staggering conclusion: that there is only one thing. Not one kind of thing, but one individual reality - infinite, eternal, and self-contained - of which every star, every mind, every stone, and every thought is merely a passing modification. He called this one reality by two names at once: God and Nature. In Latin, Deus sive Natura - ‘God, or Nature’ - the sive meaning ‘or’ in the sense of ‘in other words’. To grasp Spinoza you must hold these two ideas together: the God of the philosophers and the whole of nature are, for him, the very same infinite being.
This was an idea so radical that it got him expelled from his own community at the age of twenty-three and condemned for atheism across Europe for a century after his death. Yet it was meant not as a denial of God but as the most exalted possible affirmation of God - a God so vast and so necessary that nothing could possibly fall outside Him. Everything that is, is in God. To understand how Spinoza reached this conclusion, we have to begin where he begins: with the idea of substance.
Spinoza inherited the word substance from a long tradition, but he gave it a razor-sharp definition: a substance is “that which is in itself, and is conceived through itself” - that is, something that does not depend on anything else either to exist or to be understood. A stone depends on other things: it was made, it can be destroyed, and to understand it you must refer to the matter and forces that shaped it. So a stone is not a substance in Spinoza’s strict sense; it is dependent through and through. A true substance, by contrast, would be utterly independent - needing nothing outside itself to exist, and intelligible entirely on its own terms.
From this definition Spinoza draws a chain of consequences with geometric necessity. If a substance depends on nothing else, then nothing else can cause it; so it must be self-caused (causa sui) - its very essence involves existence, meaning it cannot not exist. And a substance must be infinite: for if it were finite, it would be limited by something else of the same kind, and so would depend on that other thing for its boundary - contradicting its independence. So whatever is a substance must be self-caused, necessarily existing, and infinite. The question then becomes: how many such substances can there be?
If there is only one substance - God, or Nature - then what are all the ordinary things we see: trees, bodies, thoughts, this page? Spinoza’s answer is that they are modes - modifications or affections of the one substance. A mode is “that which exists in, and is conceived through, something other than itself”. Where substance is in itself, a mode is in another. The relation is something like that of waves to the ocean: the waves are not a second thing alongside the water; they are the water itself, taking a passing shape. Every finite thing - you, a galaxy, a fleeting emotion - is a wave on the infinite ocean of God-or-Nature, a particular and temporary way in which the one substance expresses itself.
This reframes everything. Each finite thing depends entirely on God for its existence and is fully intelligible only as a modification of God; nothing has independent standing. There is no creation out of nothing at a moment in time, because God does not stand apart from the world to create it; rather, all things follow from the divine nature with the same necessity by which it follows from the nature of a triangle that its angles sum to two right angles. The universe is not made; it is implied. To exist is to be a mode of God - and to understand anything truly is to understand how it follows from, and exists within, the one infinite substance.
This is the opening of the lesson. The rest — the dialogue, the primary source, and the recall — is in the app.
You learned that Spinoza recognised only one substance - infinite, self-caused, necessarily existing - and identified it with both God and Nature ( Deus sive Natura ). Explain why he thought there could be only one substance, and what it means to call it God.
Leads to Rene Descartes.
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