David Spurrett

This chapter applies the parity principle in discussing “active externalism,” which claims that the mind need not be confined within either the brain or body. Consequently, how one brain or body interacts with other brains and bodies must be explored, together with the problems that may arise out of this interaction. This chapter is not concerned with beliefs and desires as mental states but whether they play a role in controlling behavior. It argues the notion that any course of action considered part of the cognitive process going on inside the brain is still part of the cognitive process no matter where it is being implemented. Divided into two parts, this chapter first establishes some points of reference regarding language and cognition, and then proceeds to an attempt to connect the issues by directly discussing the parity principle.

Parts of the genome of a single individual can have conflicting interests, depending on which parent they were inherited from. One mechanism by which these conflicts are expressed in some taxa, including mammals, is genomic imprinting, which modulates the level of expression of some genes depending on their parent of origin. Imprinted gene expression is known to affect body size, brain size, and the relative development of various tissues in mammals. A high fraction of imprinted gene expression occurs in the brain. Biologists including Hamilton, Trivers and Haig have proposed that this may explain some intrapersonal conflict in humans. This speculation amounts to an inference from conflict within the genome to conflict within the brain or mind. This is a provocative proposal, which deserves serious attention. In this paper I assess aspects of Haig’s version of the proposal. I argue, first, that the notion that intragenomic conflict predicts personal inconsistency should be rejected. Second, while it is unlikely that it credibly predicts sub-personal agents representing conflicting genetic interests, it is plausible that it predicts that the division of cognitive labour could be exploited to turn sub-systems into proxies for conflicting interests.

We discuss Russell's 1913 essay arguing for the irrelevance of the idea of causation to science and its elimination from metaphysics as a precursor to contemporary philosophical naturalism. We show how Russell's application raises issues now receiving much attention in debates about the adequacy of such naturalism, in particular, problems related to the relationship between folk and scientific conceptual influences on metaphysics, and to the unification of a scientifically inspired worldview. In showing how to recover an approximation to Russell's conclusion while explaining scientists' continuing appeal to causal ideas (without violating naturalism by philosophically correcting scientists) we illustrate a general naturalist strategy for handling problems around the unification of sciences that assume different levels of naïveté with respect to folk conceptual frameworks. We do this despite rejecting one of the premises of Russell's argument, a version of reductionism that was scientifically plausible in 1913 but is not so now.

Bhaskar's articulation of his ‘transcendental realism' includes an argument for a form of causal emergence which would mean the rejection of physicalism, by means of rejecting the causal closure of the physical. His argument is based on an analysis of the conditions for closure, where closed systems manifest regular or Humean relations between events. Bhaskar argues that the project of seeking closure entails commitment to a strong reductionism, which in turn entails the impossibility of science itself, and concludes that we should endorse causal emergence. I argue that Bhaskar's case grossly overreaches itself, and that he fails to establish the emergentist conclusions which he asserts. Consequently his programme poses no significant threat to physicalism.