  ‘Qualia’ is an especially confusing piece of terminology, even by the standards of the profession that brought us ‘realism’. In the sense just explained, the claim that experiences have qualia seems fairly  harmless.[4]  The innocent student might well be puzzled, then, to learn of Frank Jackson’s controversial “knowledge argument for qualia” (Jackson 1982), and Dennett’s attempt to dismiss qualia as a philosopher’s invention (Dennett 1988). But on closer examination, much of this apparent disagreement is merely terminological. On Jackson’s use of the term, qualia are properties of mental states “which no amount of purely physical information includes” (1982, 273); on Dennett’s, they are “ineffable”, “intrinsic”, “private”, and “directly or immediately apprehensible in consciousness” (1988, 229; cf. Tye 2002, 447). And none of this is part of the official explanation of ‘qualia’ in the previous section.