Access Internalism and the Extended Mind

The main goal of this chapter is to argue that accessibilism in epistemology is incompatible with vehicle externalism in the philosophy of mind (also known as “the extended mind thesis”). As we shall see, however, there are strong arguments for both of these positions. On the one hand, there is a compelling argument for vehicle externalism: the parity argument from Clark and Chalmers (1998). On the other hand, there is a compelling argument for accessibilism: the Moorean argument from Smithies (2012). If accessibilism is incompatible with vehicle externalism, then both arguments cannot be sound. I resolve the tension by arguing that the Moorean argument succeeds, while the parity argument fails, and hence that vehicle externalism should be rejected on broadly epistemological grounds.

From Content-Externalism to Vehicle-Externalism

ABSTRACT: Consensus has it that Putnam-Burge style arguments for content-externalism do not strengthen the case for vehicle-externalism, i.e., the thesis that some mental states include as their parts notebooks, iPhones, and other extra-bodily phenomena. Rowlands and Sprevak, among others, argue that vehicle-externalism gets stronger support from Clark and Chalmers’s parity principle and functionalism, generally. I contest this assessment and thereby give reason to reconsider the support that content-externalism provides the extended mind thesis: although content-externalism does not entail vehicle-externalism, as Rowlands argues, neither does functionalism. The functionalist cannot reject the content-externalist argument for vehicle-externalism on these grounds without undercutting her own.