In common with the tradition of metaphysical thought that descends from Aristotle, Leibniz conceives of the most basic form of existence as substance. Within the created world, substance is the only being that exists per se: the only being whose existence depends on that of no other being except God. By contrast, the existence of all other things depends in an essential way on that of substance. Given the priority thus assigned to substance, it is obvious that any metaphysical theory must devote considerable attention to an account of its nature. Our concern in this chapter will be with the distinctive features of Leibniz's doctrine of substance, which he himself acknowledges as largely determining the content of his metaphysical system.

The Characteristics of Substance

In Book II of his Essay Concerning Human Understanding, Locke writes of the scholastic notion of substance:

Responding to this passage in the New Essays, Leibniz declares that he is “of another opinion,” and that “the consideration of substance is one of the most important and most fruitful questions in philosophy” (II, xiii, 20; RB 150).