 Whitehead rejected Newton’s conception of nature as the succession of instants of spatial distribution of bits of matter for two reasons. First: the concept of a “durationless” instant, “without reference to any other instant”, renders unintelligible the concepts of “velocity at an instant” and “momentum at an instant” as well as the equations of motion involving these concepts (1934 [2011: 47]). Second: the concept of self-sufficient and isolated bits of matter, having “the property of simple location in space and time” (1925 [1967: 49]), cannot “give the slightest warrant for the law of gravitation” that Newton postulated (1934 [2011: 34]). Whitehead wrote: