Abstract

The main claim of this paper is that Andy Clark's most influential argument for ‘the extended mind thesis’ (EM henceforth) fails. Clark's argument for EM assumes that a certain form of common-sense functionalism is true. I argue, contra Clark, that the assumed brand of common-sense functionalism does not imply EM. Clark's argument also relies on an unspoken, undefended and optional assumption about the nature of mental kinds—an assumption denied by the very common-sense functionalists on whom Clark's argument draws. I also critique Mark Sprevak's reductio of Clark's argument. Sprevak contends that Clark's argument does not merely entail EM; it entails an extended mind thesis so strong as to be absurd. He goes on to claim that Clark's argument should properly be viewed as a reductio of the very common-sense functionalism on which it depends. Sprevak's argument shares the flaw that afflicts Clark's argument, or so I claim.