Full Idea
All things are conditioned by the necessity of the divine nature, not only to exist, but also to exist and operate in a particular manner, and there is nothing that is contingent.
Gist of Idea
Divine nature makes all existence and operations necessary, and nothing is contingent
Source
Baruch de Spinoza (The Ethics [1675], I Pr 29)
Book Reference
Spinoza,Benedict de: 'Ethics, Improvement of Understanding, Letters', ed/tr. Elwes,R [Dover 1955], p.68
A Reaction
This obviously invites the response of the empiricist: how does he know that? Hume says he can't know it, and Leibniz says he knows it a priori. Traditionally, 'necessary' is the dubious term, but maybe it is 'contingent' which is meaningless.