Demystifying Emergence

Abstract

Are the special sciences autonomous from physics? Those who say they are need to explain how dependent special science properties could feature in irreducible causal explanations, but that’s no easy task. The demands of a broadly physicalist worldview require that such properties are not only dependent on the physical, but also physically realized. Realized properties are derivative, so it’s natural to suppose that they have derivative causal powers. Correspondingly, philosophical orthodoxy has it that if we want special science properties to bestow genuinely new causal powers, we must reject physical realization and embrace a form of emergentism, in which such properties arise from the physical by mysterious brute determination. In this paper, I argue that contrary to this orthodoxy, there are physically realized properties that bestow new causal powers in relation to their realizers. The key to my proposal is to reject causal-functional accounts of realization and embrace a broader account that allows for the realization of shapes and patterns. Unlike functional properties, such properties are defined by qualitative, non-causal specifications, so realizing them does not consist in bestowing causal powers. This, I argue, allows for causal novelty of the strongest kind. I argue that the molecular geometry of H2O—a qualitative, multiply realizable property—plays an irreducible role in explaining its dipole moment, and thereby bestows novel powers. On my proposal, special science properties can have the kind of causal novelty traditionally associated with strong emergence, without any of the mystery.