Central to Spinoza’s philosophy is the idea, similar to that of Parmenides, that everything in the universe is One. There is only one substance and that substance we can conceive of as either Nature or God. This substance has infinitely many attributes but human beings, being finite, can only perceive two of them, extension and thought. Unlike Descartes, who thought mind and body were two separate kinds of thing, Spinoza argues that mind and body are just different ways of conceiving the same reality.
