Abstract

This journey shall provide the reader with a simple, though complete, guide to Leibniz’s metaphysics, incidentally preventing him or her from common errors. I will start with unfolding Leibniz’s definition of a simple substance as a free acting individual substance, which, in doing so, constitutes its complete concept. This latter contains everything that happens to the individual substance, a process taking place in God’s mind by forming the possibilities as combinations of his attributes before his decision to create the best world. The totality of possibilities is divided through the compatibility relation into possible worlds. A world is a collection of all compatible individual substances. God creates the best among all possible worlds. The journey will enlighten the reader on Leibniz’s technical distinction between “possible” and “contingent”. In short, “possible” is defined by Leibniz in logical terms, as what is contradiction-free. “Contingent” is something that is, but might have been not. Just the fact that the non-being of contingent things remains possible saves Leibniz from Descartes’ and Spinoza’s determinism.