Abstract

: Phenomenal knowledge usually comes from experience. But it need not. For example, one could know what it’s like to see red without seeing red—indeed, without having any color experiences. Daniel Dennett (2007) and Pete Mandik (forthcoming) argue that this and related considerations undermine the knowledge argument against physicalism. If they are right, then this is not only a problem for anti‐physicalists. Their argument threatens to undermine any version of phenomenal realism— the view that there are phenomenal properties, or qualia, that are not conceptually reducible to physical or functional properties. I will argue that this threat is illusory. Explaining why will clarify what is and is not at issue in discussions of the knowledge argument and phenomenal realism. This will strengthen the case for physically and functionally irreducible qualia. 2 Phenomenal knowledge usually comes from experience. For example, I know what it’s like to see red because I have done so. Does knowing what it’s like to have an experience with phenomenal character X require having an experience with X? No. A famous counterexample is Hume’s missing shade of blue, in which one can extrapolate from phenomenally similar experiences (A Treatise of Human Nature, Bk. I, Pt. I, Sec. I).1 One might think that a weaker version of the no‐phenomenal‐knowledge‐without‐experience thesis remains tenable, e.g., that knowing what it’s like to see in color requires having or having had color experiences. But this thesis also seems doubtful. Peter Unger (1966) devised plausible counterexamples over four decades ago, and since then others (e.g., Lewis 1988, Alter 1998, Stoljar 2005) have done the same. One could have phenomenal knowledge of color experiences without having such experiences. Indeed, one could have such knowledge without having experiences that are remotely like color experiences. What is the significance of this observation for contemporary debates about consciousness and physicalism? Daniel Dennett (2007) and Pete Mandik (forthcoming) suggest that it undermines the knowledge argument against physicalism.2 That is because they take the claim that someone who has never seen in color could not know what it’s like to see in color to be the basis of the knowledge argument’s main epistemic premise: the premise that (roughly put) 3 no amount of physical knowledge is sufficient for phenomenal knowledge of color experiences. If they are right, then this is not only a problem for anti‐ physicalists. Many physicalists (e.g., Loar 1990/97, Papineau 2002, 2007) accept the knowledge argument’s epistemic premise. Dennett’s and Mandik’s arguments threaten all versions of what David Chalmers (2003) calls phenomenal realism, the view that there are phenomenal properties, or qualia, that are not conceptually reducible to physical or functional properties.3 I will argue that this threat is illusory. Explaining why will clarify what is and is not at issue in discussions of the knowledge argument and phenomenal realism. The net result will be to strengthen the case for physically inexplicable qualia