A Causal Theory of Constitution and Persistence

In The Possibility of Metaphysics, Jonathan hoped that a causal account of the persistence of compound entities might be forthcoming in future. I will argue that my account of causation in terms of reciprocal interaction (Ingthorsson 2002) allows us to understand the persistence and constitution of compound entities—roughly as these phenomena are standardly explained by the empirical sciences—as causal phenomena. Like other powers-based accounts, I characterise effects as the mutual manifestation of reciprocal interactions between powerful particulars. However, most friends of powers follow the Aristotelian tradition in construing interactions between powerful particulars as unidirectional; one object acts while the other receives the influence. The problem is that modern science does not recognise any form of unidirectional action. It insists that whenever one object exerts an influence on another, the latter simultaneously exerts a proportional influence of the same kind on the first, but in the opposite direction. My account of causation accepts the reciprocity of causal interactions, and that allows me to include in the class of causal phenomena all physical bonds postulated by the sciences to explain the constitution of material entities and why they continue to constitute them over time. Such bonds are standardly described in terms of reciprocal interactions between constituent parts of any given compound. On my view, change, constitution, and persistence are merely different sides of the same coin: causation.