ABSTRACT
"The theory of matter" can mean many things, ranging from the most abstract metaphysical issues about persistence and change, identity and individuation, down to detailed empirical issues about the actual constitution of bodies. This chapter details some of the key issues of Scholastic matter theory that provided the framework for seventeenth century natural philosophy. The substantial forms (SFs) of the Scholastics were the target of severe and sustained criticism from almost all of the "moderns" in the seventeenth century. By replacing the Aristotelian notion of gravity as the inner striving of a heavy body towards its natural place with his own rival account of a purely external impulse by currents of subtle matter, Rene Descartes marks a decisive shift in natural philosophy. In the writings of Robert Boyle, a systematic attempt is found to articulate a theory of matter that is studiedly neutral between those of Descartes and Pierre Gassendi, stressing their similarities and downplaying their differences.
