ABSTRACT
In this chapter, the author argues that John Locke is in fact a consistent mechanist. Locke subscribed to the Mechanical Philosophy, in Pierre Gassendi's and Robert Boyle's version of it. On this view, all of the powers and qualities of bodies, and all the changes in these powers and qualities which result from the actions of these bodies one upon the other, issue entirely from the "two grand principles of bodies, matter and motion". The author identifies more precisely the obstacle to a straightforward reading of Locke as a mechanist. Locke is giving a reductio argument against the Scholastic doctrine of substantial forms, which he interprets as holding, in effect, that the real essence of a body is its nominal essence. Even given the high standards Locke set for explanation in natural philosophy, then, there is no inconsistency between his commitment to mechanism and his treatment of secondary qualities, or of superadded qualities in general.
