"[T]he mere fact that a quantitative majority of causations are of vitalistic type, does not in the least mean that science can neglect the huge, co-existing volume of mechanistic-type causations. Both aspects of causal description are required in all sciences. In physics, for example, which seeks to describe the most ultimate, or elementary reaction tendencies of matter, the attempt is now being made to resolve all complex masses into ultra-simple proton and electron systems. The influence of each proton-electron microcosm, then must be traced in its most far-reaching effects upon the physical behavior of the macrocosmic mass of which it forms a single unit. The causal influences of the total mass, on the other hand, upon its constituent proton-electron systems, and upon other free-lance proton-electron systems, must be described."