The Ethics - Ethica Ordine Geometrico Demonstrata by Benedict de Spinoza Translated from the Latin by R. H. M. Elwes Ethics, Demonstrated in Geometrical Order (Latin: Ethica, ordine geometrico demonstrata), usually known as the Ethics, is a philosophical treatise written by Benedict de Spinoza. It was written between 1664 and 1665 and was first published in 1677. The first part of the book addresses the relationship between God and the universe. Tradition held that God exists outside of the universe, created it for a reason, and could have created a different universe if he so chose. Spinoza denies each point.

According to Spinoza, God is the natural world. As with many of Spinoza's claims, what this means is a matter of dispute. Spinoza claims that the things that make up the universe, including human beings, are God's "modes." This means that we and everything else are, in some sense, dependent upon God. The nature of this dependence is disputed. Some scholars say that the modes are properties of God in the traditional sense. Others say that modes are effects of God. Either way, the modes are also logically dependent on God's essence, in this sense: everything that happens follows from the nature of God, just like how (as Spinoza puts it) it follows from the nature of a triangle that its angles are equal to two right angles.

Since God had to exist with the nature he happens to have, nothing that has happened could have been avoided, and if a particular fate for a particular mode is fixed by God, there is no escaping it, or as Spinoza puts it, "A thing which has been determined by God to produce an effect cannot render itself undetermined." God's creation of the universe is not a decision, much less one motivated by a purpose.