In this article, I start with the assumption that all fundamental monadic properties dispositional quantity tropes. I argue that the dispositional tropes and the causal processes they produce can, in relevant part, account for the truth of causal functional laws (such as Coulomb law): laws of nature that describe the forces the quantitative properties falling under a determinable generate as a function of their distance. Following Ellis & Lierse (1994) and Ellis (2001), I adopt the claim that a large group of the dispositional properties figuring in functional laws are causal powers and that their manifestations are causal processes. The forces (gravitational force, Coulomb force) resulting from these causal processes are connected by the proportion relations in accordance with the formal proportion relations between the tropes producing the processes. Hence, property tropes and the respective causal processes suffice to secure that the resulting forces accord with the functional formula.