Abstract

In Book IV Chapter iii of the _Essay_, Locke defends his famous thinking-matter hypothesis. This chapter addresses some major issues of interpretation that this hypothesis raises. It is argued that Locke commits himself to the logical, not just the epistemic, possibility of thinking matter. It is further argued that when Locke discusses the role that God might play in superadding a power of thinking to matter, his concept of superaddition is a weak one; such an interpretation leaves room for Locke’s claim that it is only to material systems ‘fitly disposed’ that God can superadd a power of thinking. The chapter concludes by discussing the philosophical relationship between Locke’s thinking-matter hypothesis and the Newtonian theory of universal gravitation with which Locke was familiar.