Jessica M. Wilson

Horgan (1993) proposed that "superdupervenience" - supervenience preserving physicalistic acceptability - is a matter of robust explanation. I argued against him (1999) that (as nearly all physicalist and emergentist accounts reflect) superdupervenience is a matter of Condition on Causal Powers (CCP): every causal power bestowed by the supervenient property is identical with a causal power bestowed by its base property. Here I show that CCP is, as it stands, unsatisfactory,for on the usual understandings of causal power bestowal, it is trivially satisfied or falsified. I offer a revision of CCP which incorporates the evident fact that causal powers are grounded in fundamental forces.

The nonlinearity of a composite system, whereby certain of its features (including powers and behaviors) cannot be seen as linear or other broadly additive combinations of features of the system's composing entities, has been frequently seen as a mark of metaphysical emergence, coupling the dependence of a composite system on an underlying system of composing entities with the composite system's ontological autonomy from its underlying system. But why think that nonlinearity is a mark of emergence, and moreover, of metaphysical rather than merely epistemological emergence? Are there diverse ways in which nonlinearity might enter into an account of properly metaphysical emergence? And what are the prospects for there actually being phenomena that are metaphysically emergent in any available sense? Here I explore the mutual bearing of nonlinearity and metaphysical emergence, with an eye towards answering these and related questions.

Hume argued that experience could not justify commonly held beliefs in singular causal effcacy, according to which individual or singular causes produce their effects or make their effects happen. Hume's discussion has been influential, as motivating the view that Causal reductionism (denying that causal efficacy is an irreducible feature of natural reality) requires Causal generalism (according to which causal relations are metaphysically constituted by patterns of events). Here I argue that causal reductionists---indeed, Hume himself---have previously unappreciated resources for making sense of Causal singularism, associated with a relation that has been curiously underexploited in the causation debates: resemblance. The core idea I explore here is that causation may be metaphysically and epistemologically indicated by the coming-to-be of a resemblance. Comings-to-be of resemblances are epistemically available in the singular instance, even by Hume's strict lights, and, I argue, can justify (albeit fallibly) belief in the holding of singular causal relations; hence Hume's general argument for generalism fails. More to the contemporary metaphysical point, comings-to-be of resemblances provide valuable resources for existing singularist accounts: while neither changes (Ducasse) nor transfers of physical quantities (Fair, Dowe, Salmon) provide a suffciently fine-grained basis for the individuation of causes, either changes or transfers, in combination with comings-to-be of resemblances, can do so.