 (i) Quantum-physical processes: When Whitehead turned from mathematics to philosophy, he was quite aware that recent developments in physics (the demise of classical atomism in the face of quantum theory and relativity theory) had thrown out our old common-sense vision of the order of the universe. Quantum physics brought on the dematerialization of physical matter—matter in the small could no longer be conceptualized as a Rutherfordian planetary system of particle-like objects. The entities described by the mathematical formalism seemed to fit the picture of a collection of fluctuating processes organized into apparently stable structures by statistical regularities—i.e., by regularities of comportment at the level of aggregate phenomena. During the early decades of the twentieth century process philosophers were excited by the evidence that physics had turned the tables on the core refuge of substance metaphysics: classical atomism. Instead of very small things (atoms) combining to produce standard processes (avalanches, snowstorms) modern physics seemed to suggest that very small processes (quantum phenomena) combine to produce standard things (ordinary macro-objects) as a result of an as yet not understood modus operandi that could, nevertheless, be mathematically described. So-called enduring “things” in this picture would come about through the emergence of stabilities in statistical fluctuations, as a stability wave in a surging sea of process, metaphorically speaking.