The last of the magicians

Over the next three chapters we will be examining the debates concerning motion and space in the context of classical Newtonian mechanics. Newton himself will be playing the role of arch-substantivalist and Leibniz the arch-relationist, with Galileo and Descartes fitting uneasily between the two. As far as our space is concerned, this debate has in some respects been rendered redundant by subsequent developments, since Newton's physics has been replaced by Einstein's, but the earlier debate is well worth studying. Not only does it provide useful preparation – recent developments can only be fully understood against the backdrop of the positions from which they emerged – but it is also of interest in its own right, for in considering the different ways that the substantivalist and relationist can account for a basic physical phenomenon such as motion, we learn a good deal about both the character and explanatory resources of the two competing frameworks, and what we learn may well be relevant outside the narrow confines of the classical Newtonian worldview.

Newton's Principia was first published in 1687 (Philosophiae Naturalis Principia Mathematica), and in the opinion of many it is the single most important work in the history of science. Within half a century most scientists were Newtonians, and most were to remain so for the next two hundred years.