Structural versus Substantial Powers
The building blocks of all there is are instances of physical powers. They occur in nature in physical structures of dependencies. I have argued that such structures unite the powers together, but do not unify them metaphysically into individual entities. On other hand, there exist a small number of physical structures of powers that are also metaphysically unified into individual entities, on account of the way their constituents are individuated. Thus, for instance, an electron is one entity, not on account of its being physically structured, but on account of the way the powers in the structure are holistically individuated into qualifications of the electron.
There is a further point to make. The physical structure of the electron’s powers constitutes the electron, but is not the electron. The electron is an activity, namely, an activated intransitive power—an instance of the power of an electron. This is a single emergent power, constituted of a physical structure of powers—mass, spin, charge, space-time—which are holistically composed into one emergent entity, the electron, under the individuation principle of the sortal “electron”. I call the structure of powers constituting an emergent entity a structural power; the electron is constituted of a structural power—the structure of mass, spin, charge, space-time. The oneness of the structural power of the electron is derivative from the metaphysical oneness of the electron. In itself, the structural power of the electron is a structure of powers; it is a whole of many powers. Is it a power? Strictly, no; it is many powers; a powerful whole of many powers; it is literally plural powerfulness. The single power of an electron emerges from the unification of the physical structure of powers into a single individual; I call the emergent power of an electron a substantial power. This is constituted of the structure of powers of the electron, which are re-individuated as qualifications of a subject according to the principle of the sortal “electron”.
So why differentiate between a structural power and a substantial power? Isn’t the substantial power of an electron sufficient for understanding what type of power the electron is? The reason for differentiating them is twofold. On the one hand, the structural power is what constitutes the electron, whereas the substantial power is the electron. On the other, the differentiation between the structural and the substantial power of an electron enables us to understand the relation between the extensional mereological conception of the electron (as a whole of many interrelated powers) and the substantialist conception of the electron (as an individual emergent power). The constitution relation turns the powers in the physical structure into properties of the emergent substantial power. Although every structure of powers could be thought of as a structural power, I reserve the term “structural power” for those structures of powers which constitute substantial powers. (Thus the wind around me is not a structural power, but the orange is constituted of one.) Every science individuates its own individual subjects or substances, and hence its own substantial powers, i.e., the entities that the science needs to describe and investigate reality within its own domain of inquiry. These structural powers are holistically unified, top-down,3 7 according to the individuation principles of the respective concepts which figure in the scientific laws and explanations of the science in question.