Spinoza's Ethics is built like a geometry textbook — definitions, axioms, propositions, proofs — and the pantheism falls out of the first fifteen propositions rather than being asserted. If substance is what exists in itself and is conceived through itself, and if it is infinite, then there cannot be two of them, and everything else must be a modification of the one. God therefore does not create the world in the way a carpenter makes a chair; God is the world understood completely. This is why pantheists resist the description "God is everything" and prefer "everything is God" — the direction of the sentence carries the whole argument.