Dr Zoe Drayson (University of Stirling) at the Extended Knowledge conference, University of Edinburgh, 22-24 April 2015.
Abstract: Two radically externalist approaches to the mental have been proposed that go far beyond the content externalism of Putnam and Burge. Both Williamson (1995, 2000) and Clark and Chalmers (1998) argue that environmental factors are relevant to more than just the contents of mental states. Williamson argues that a factive state like knowing, which has traditionally been considered a composite of mental and non-mental environmental conditions, is in fact a ‘prime’ (non-composite) genuinely mental state⎯with important implications for epistemology. Clark and Chalmers argue that the physically-implemented vehicles of our mental states needn’t be confined to the brain, but can extend into the extra-bodily environment⎯with important implications for the methodology and practice of cognitive science. These two radically externalist approaches differ in their metaphysical presuppositions and their implications, but they appeal to similar explanatory considerations to justify their externalist claims about mental states: Williamson argues that there are cases where knowledge-citing psychological explanations are better explanations than their belief-citing alternatives, while Clark and Chalmers claim that their extended notion of belief is more useful than a non-extended notion in psychological explanations. Both parties have had the specific details of their appeals to explanatory virtue challenged, but in this paper I focus on the more general form of these arguments. Drawing on work by Potochnik (2010), Weslake (2010), and Strevens (2008), I examine the value of explanatory generality and its relation to other explanatory virtues, in order to reassess Williamson’s argument for the primeness of knowledge and Clark and Chalmers’s argument for extended minds.