Newton's early metaphysics of body: Impenetrability, action at a distance, and essential gravity

Abstract

In this paper, I discuss Newton's conception of body in De gravitatione and its relation to the legitimacy of action at a distance. Howard Stein has argued that such a conception privileges contact over distant action: by dint of being impenetrable, bodies must necessarily act through contact; yet there is no analogous property of which action at a distance is a consequence. This paper presents a challenge to Stein's reading. I begin by arguing that impenetrability cannot imply action through contact because such an implication hinges on one's laws of motion in three senses: it must be physically possible for contact to occur, the laws must make coherent the notion of a trajectory from which a body deviates, and the necessity of introducing collision dynamics renders impenetrability otiose. I then turn to a close reading of De gravitatione and consider whether Newton himself sees his account of body as establishing contact action as prior to distant action in any sense. Although Newton did see impenetrability as rendering bodily action intelligible, ample room remains for action at a distance once one takes into account certain textual ambiguities and the provisional character of the narrative. By way of substantiating this reading and answering an objection of Stein's, I pivot to Newton's remarks concerning the nature of gravity in his correspondence with Bentley. Although Newton is often held to reject essential gravity as being in conflict with his metaphysical commitments, I offer a more austere reading on which Newton is decrying a kind of action that is unmediated, or alleged to take place without a cause. By contrast, Newton carves out a place for action at a distance mediated by an immaterial agent as a perfectly acceptable explanation of natural phenomena.