This paper investigates Newton’s ontology of space in order to determine its commitment, if any, to both Cambridge neo-Platonism, which posits an incorporeal basis for space, and substantivalism, which regards space as a form of substance or entity. A non-substantivalist interpretation of Newton’s theory has been famously championed by Howard Stein and Robert DiSalle, among others, while both Stein and the early work of J. E. McGuire have downplayed the influence of Cambridge neo-Platonism on various aspects of Newton’s own spatial (...) hypotheses. Both of these assertions will be shown to be problematic on various grounds, with special emphasis placed on Stein’s influential case for a non-substantivalist reading. Our analysis will strive, nonetheless, to reveal the unique or forward-looking aspects of Newton’s approach, most notably, his critical assessment of substance ontologies, that help to distinguish his theory of space from his neo-Platonic contemporaries and predecessors. (shrink)

The widely accepted supposition that Newton’s De gravitatione was written in 1684/5 just before composing the Principia is examined. The basis for this determination has serious difficulties starting with the failure to examine the numerical estimates for the resistance of aether. The estimated range is not nearly nil as claimed but comparable with air at or near the earth’s surface. Moreover, the evidence provided most likely stems from experiments by Boyle, Hooke, and others in the 1660s and does not use (...) evidence available in the late 1684. The document supports Newton’s contention that the aether medium incorporates very large voids thereby proving that body and space differ but does by no means completely reject its corporeal nature or eliminate its resistance. Newton’s use of the term inertia provides no conclusive evidence for a late date as often claimed and his definition of gravitas is difficult to reconcile with a late one. (shrink)