Newton's neoplatonic ontology of space

substantivalism or third-way?

pp. 29-60

in: Edward Slowik, The deep metaphysics of space, Berlin, Springer, 2016

Abstract

Among philosophers of space and time, two aspects of Newton's ontology of space have seldom been questioned: first, that Newton qualifies as a substantivalist, since he reckons space to be an independently existing substance or entity (see § 1.1.1); and second, that Newton's views were deeply influenced by his seventeenth century Neoplatonic predecessors, especially Henry More, whose ontology grounds the existence of space upon an incorporeal being, i.e., God or World Spirit. While the majority of the interpretations of Newton's spatiotemporal ontology in the twentieth century supported these conclusions, a number of important investigations over the past several decades have nonetheless begun to challenge even these ostensibly safe assumptions. Among the most important of these reappraisals can be found in the work of Howard Stein (e.g., 1967, 2002) and Robert DiSalle (e.g., 2002, 2006), who both conclude that the content and function of Newton's concept of absolute space should be kept separate from the question of Newton's alleged commitment to substantivalism. More controversially, Stein (2002) further contends that Newton's natural philosophy treats space as akin to a basic fact or consequence of any existing thing, a view categorized as one of the more epistemologically-oriented, third-way alternatives in Chap.  1, i.e., the definitional conception of space, and therefore non-substantivalist. A related, albeit much more nuanced, interpretation that parts company with traditional substantivalism may also be evident in an influential article by J. E. McGuire (1978a), who argues that space for Newton is "the general condition required for the existence of any individual substance" (1978a, 15). As regards the second of our traditional assumptions associated with Newton's spatial ontology, Stein (2002, 269) forthrightly rejects any Neoplatonic content, whereas McGuire's (1983) essay conjectures that, though "Platonic in character", the primary influence on Newton's ontology is "Descartes' Meditations, rather than the eclecticism of Renaissance Neo-Platonism, of which we find little evidence in De gravitatione" (1983, 152).