What a powerful world: dispositional properties as the best description of the fundamental elements of the physical reality

This paper is meant to offer a better understanding of the philosophical view called ‘powers ontology’ and its relevance to science. After briefly discussing on the one hand the intuitive pull of dispositional notions and their application in science (micro-physics in particular), and on the other hand the metaphysical and epistemological issues typically arising from the application of powers in science, we defend a dynamic notion of the dispositional essence, where the individuation of the power does not the depend on the manifestations brought about by a certain activity, nor the stimulus conditions enabling such activity, but on the very activity itself. In the last part of the paper, we discuss two cases of theoretical unification in early 20th century physics: Einstein’s equivalence principle and de Broglie wave-particle duality principle. We show how a powers ontology, intended in the sense described above, would be able to elegantly account for how these unifications were achieved and why they were successful.