Abstract
In this paper I discuss a variant of the knowledge argument which is based upon Frank Jackson's Mary thought experiment. Using this argument, Jackson tries to support the thesis that a purely physical â or, put generally: an objectively scientific â perspective upon the world excludes the important domain of `phenomenal' facts, which are only accessible introspectively. Martine Nida-Rümelinhas formulated the epistemological challenge behind the case of Mary especially clearly. I take her formulation of the problem as a starting-point and present a solution which is based solely on the concepts of capability and of metalinguistic beliefs. References to epiphenomenal facts, phenomenal knowledge etc. will be avoided completely. I specify my proposal against the backdrop of Burge's critical reflections about metalinguistic reinterpretation of expressions of belief and the externalist thesis held by Burge, Putnam and others that meanings and mental states are dependent upon the environment. My solution is then compared with Lewis' and Nemirow's ability objection. Finally I argue that the much discussed ``knowing what it is like'' has in its ordinary meaning nothing much to do with `phenomenal knowledge' or knowledge of `epiphenomenal' facts