tury to the concept of Nature suggested by the speculative physics of the present day. This change of view, occupying four centuries, may be characterized as the transition from space and matter as the fundamental notions to process conceived as a complex of activity with internal telations between its various factors. The older point of view enables us to abstract from change and to conceive of the full reality of Nature at an instant, in abstraction from any temporal duration and characterized as to its interrelations solely by the instantaneous distribution of matter in space. According to the Newtonian view, what had thus been omitted was the change of distribution at neighbouring instants. But such change was, on this view, plainly irrelevant to the essential reality of the material universe at the instant considered. Locomotion, and change of relative distribution, was accidental and not essential, Equaliy accidental was endurance.
