Abstract I argue that examining the explanatory power of the hypothesis of extended cognition (HEC) offers a fruitful approach to the problem of cognitive system demarcation. Although in the discussions on HEC it has become common to refer to considerations of explanatory power as a means for as Keywords: Extended Cognition; Explanatory Power; Mechanism; Pluralism * I wish to thank the participants in the PPIG seminar at the University of Edinburgh (2010), the philosophy of science research seminar at the University of Helsinki (2012) and the philosophy colloquium at the Berlin School of Mind and Brain (2012) for their useful comments on earlier versions of this paper. I am also grateful to Cameron Buckner for his valuable comments and suggestions on an earlier draft
