Abstract

Recent influential interpreters have argued that the philosophy of body that prevails in Leibniz's writings from the 1680' s to about 1704 is both more Aristotelian and less idealistic than the ' monadology' of his last years. It is argued here that the Aristotelian terminology of matter and form which is undoubtedly prominent in the work of Leibniz's ' middle years' was understood by him in a sense that is consistent with the monadology. The monadology is foreshadowed, moreover, in important arguments against the Cartesian thesis that extension is the essence of corporeal substance. Leibniz can be seen as a sort of realist in physics, in contrast with occasionalists. But what is important in that contrast is not so much the reality of matter, as the reality of form, which Leibniz interpreted in terms of the active powers of soul-like substances.