Substance, power, & the mystery of cohesion

Locke's account of the problem of cohesion reflects a serious difficulty in his philosophy. What makes it more problematic is the way in which Locke himself relates it with the problem of substance (something about which "we know not what") in his search for something that not only underlies all properties in the traditional Aristotelian sense, but also holds the constituents of matter together. His account of substance was neither a sincere nor ironic way of reporting our ordinary talk about substance. Instead, Locke was looking for something that really holds qualities and particles together. In this respect, it is generally assumed that Locke had in mind a metaphysical entity that underlies qualities. I argue, however, that Locke's concern was different. He was more inclined to think that something like a cohesive power is what functions as the "cement" or the "bond" that ties and holds together, not only the qualities of a substance, but its individual corpuscles, and also on a deeper level even the parts of one single corpuscle. The latter question is generally ignored by commentators, but Locke clearly talks about the divisibility of matter ad infinitum and raises the question what makes even a quality such as material extension possible in the first place, given that divisibility, Locke grants, however, that we have no real understanding of the cohesive power that must be in question. To clarify the issue of cohesion we have first to clarify Locke's talk about qualities in general and power in particular (Chapter One). Chapter Two is an attempt to understand Locke's account of substance in its relation to the concepts of real essence and cohesion. Chapter Three deals with the problem of cohesion in more detail, including some related issues considered by Locke and some commentators, such as solidity and hardness. The Epilogue explain to a certain extent why cohesion cannot be explained in Locke's philosophy' in terms of an act of divine superaddition.