 Key to this line of defense is the claim that these special phenomenal concepts can denote functional (or physical) properties without expressing some irreducibly qualitative modes of presentation of them, for otherwise it couldn't be held that these concepts do in fact apply to our functional (or physical) duplicates, even though it's conceivable that they don't. This, not surprisingly, has been disputed, and there is currently much discussion in the literature about the plausibility of this claim. If this line of defense is successful, however, it can also provide a response to the “Distinct Property Argument”, discussed in section 3.3. (See Chalmers 1999, Holman, 2013 for criticism of this view, but see the responses of Loar 1999, and Hill and McLaughlin 1999, Balog, 2012, Levin, 2008, forthcoming, Diaz-Leon, 2010, 2014; see also see Levin 2002, 2008, and Shroer, 2010, for the presentation, if not endorsement, of a hybrid view.) 