Whose (Extended) Mind Is It, Anyway?

Presentations of the extended mind thesis are often ambiguous between two versions of that thesis. According to the first, the extension of mind consists in the supervenience base of human individuals’ mental states extending beyond the skull and into artifacts in the outside world. According to a second interpretation, human individuals sometimes participate in broader cognitive systems that are themselves the subjects of extended mental states. This ambiguity, I suggest, contributes to several of the most serious criticisms of the extended mind thesis, for these criticisms only apply to the first interpretation of the thesis. In what follows, I argue that several significant objections to the extended mind thesis fail to undermine the latter interpretation of that thesis. Having defended the second interpretation, I argue that the extension of mind does not involve the extension of self. Consequently, the subject of extended mental states is not the same individual whose causal coupling with external artifacts gives rise to extended mentality.