Abstract

In his writings Leibniz employs both the notions of possible worlds and of necessary truths but he does not define necessary truths by reference to possible worlds. This paper is intended to show that modern attempts to interpret Leibniz's notion of necessary truth in terms of possible worlds go wrong on two accounts : 1) they disregard the consequences of Leibniz's thesis that the actual world is the best of all possible worlds and his acceptance of the scholastic principle, "What does not exist has no properties"; 2) they do not reflect upon the implications of Leibniz's theory of the complete concept for the emergence of 'new' truths. These two objections are preceded by, and partly depend on, a discussion of what Leibniz actually means by ' necessary truths'