  Hobbes and Spinoza, despite their own differences, advanced, or were read as advancing, a number of objectionable and deeply troubling theses which Leibniz (and most of his contemporaries) saw as an enormous threat: materialism, atheism, and necessitarianism. It is Leibniz's response to Hobbesian and Spinozistic necessitarianism that is perhaps of greatest interest, for he sought to develop an account of action and contingency that would preserve divine and human freedom. As will be shown, central to Leibniz's philosophy was the view that God freely chose the best world from an infinite number of possible worlds and that a person could be said to act freely when the contrary of that action does not imply a contradiction. (This topic will be addressed principally in the article on Leibniz's Modal Metaphysics.)