Volume 17, December 2007
Quod non omnia possibilia ad existentiam perveniant
Leibniz’s ontology of possibility, 1668-1678
In the Nouveaux Essais, Leibniz famously declared that he once had “begun to lean towards” Spinozist necessitarianism. In this article, I argue that this remark refers to his modal philosophy anterior to 1677. Leibniz’s mature refutation of Spinoza’s necessitarianism relies on the notion that pure possibility has some sort of reality in God’s mind, because only this allows for a strong notion of divine choice. But I believe that Leibniz only developed this ontology of possibility after 1677. Before this date, he inclined towards the view that non existing possibilities are mere logical abstractions that God never actually conceives. In order to show this, I analyze a series of early texts written between 1668 and 1676. Next, I consider a series of texts from 1677-1678, where Leibniz developed his ontology of possibility and put it to use against Spinozist necessitarianism for the first time.