Newton's De gravitatione: a review and reassessment

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.