Starting from Leibniz’s complaint that Newton’s views seem to make God the soul of the world, this paper examines Leibniz’s critical stance more generally towards God as the soul of the world and related theses. A preliminary task is determining what the related theses are. There are more of these than might have been thought. Once the relations are established, it becomes clear how pervasive the various guises of the issue of God as the soul of the world are in Leibniz’s thought and how central they are in his debates with contemporaries about the truths of natural religion and even more strictly philosophical issues. Leibniz’s arguments against God as the soul of the world are reconstructed and evaluated, and the difficult question of the exact meaning, or meanings, that Leibniz ascribes to the thesis that God is the soul of the world is taken up. The clearest core of meaning discussed in this paper is most directly relevant to Leibniz’s criticisms of Spinoza and the Stoics, as well as of Descartes. Less clear, but obviously important, are meanings relevant to Leibniz’s debates with the occasionalists and Newtonians.

Contrary to popular belief, I argue that Leibniz is not hopelessly confused about motion: Leibniz is indeed both a relativist and an absolutist about motion, as suggested by the textual evidence, but, appearances to the contrary, this is not a problem; Leibniz’s infamous doctrine of the equivalence of hypotheses is well-supported and well-integrated within Leibniz’s physical theory; Leibniz’s assertion that the simplest hypothesis of several equivalent hypotheses can be held to be true can be explicated in such a way that it makes good sense; the mere Galilean invariance of Leibniz’s conservation law does not compromise Leibniz’s relativism about motion; and Leibniz has a straightforward response to Newton’s challenge that the observable effects of the inertial forces of rotational motions empirically distinguish absolute from relative motions.

In this paper I challenge the common view that early in his career (1679-1695) Leibniz held that space and time are well-founded phenomena, entities on an ontological par with bodies and their properties. I argue that the evidence Leibniz ever held that space and time are well-founded phenomena is extremely weak and that there is a great deal of evidence for thinking that in the 1680s he held a position much like the one scholars rightly attribute to him in his mature period, namely, that space and time are merely orders of existence and as such are purely abstract and occupy an ontological realm distinct from that of well-founded phenomena. In the course of arguing for this interpretation, I offer an account of the nature of Leibnizian phenomena which allows Leibniz to hold the view that space and time are phenomena, while at the same time thinking of them as abstract, ideal orders of existence.