The Metaphysics of Ontological Emergence

Emergence is the metaphysical buzzword of the last decade. This dissertation investigates ontological emergence (OE), a concept prevalent in contemporary philosophy of mind and science. An ontologically emergent property (hereafter, emergent property) is causally efficacious, irreducible to microphysical properties, and yet still dependent upon microphysical properties. Though this basic idea is clear, there is considerable disagreement in the literature as to the exact nature of emergent properties, and this motivates this dissertation.

Chapter One introduces some metaphysical assumptions and concepts regarding properties and causation. Particular attention is given to the frequently invoked yet under-analyzed notion of causal power contribution. An analysis distinct from Shoemaker's and Armstrong's is suggested.

Chapter Two situates OE among solutions to the Problem of the Special Sciences, the problem of identifying the referents of special science predicates. It is suggested that recent formulations of OE invoke too many necessary conditions upon an emergent property. It is contended that a more modest formulation of OE is sufficient to distinguish OE from its main rivals' epiphenomenalism, micro-determinism, and standard nonreductive physicalism.

Chapter Three reviews two Kimian arguments against British Emergentism, one of which is shown to be unsound and the other not injurious to the more modest formulation of OE suggested in Chapter Two.

The fourth chapter houses a taxonomy of theories of OE. Such theories can be classified along two dimensions, the first being the type of dependence relation holding between emergent properties and microphysical properties and the second being the way in which an emergent property is causally efficacious. Mere supervenience, causal dependence, and two distinct types or realization are the examined dependence relations (with original analyses of mere supervenience and realization proffered). Novel causal contribution and synchronic non-causal determination are the competing understandings of causal efficacy. This suggests eight distinct, logically possible theories of OE. The prospects for each are briefly discussed.

The dissertation concludes with a review of theories proffered by Derk Pereboom and Carl Gillett. It is argued that both suffer from internal problems that preclude judging them to be true. Nonetheless, much is to be learned by noting where they go wrong.