  Nonetheless the type-type identity theory has enjoyed a recent if modest resurgence at least with respect to qualia or qualitative conscious properties. This has been in part because treating the relevant psycho-physical link as an identity is thought by some to offer a way of dissolving the explanatory gap problem (Hill and McLaughlin 1998, Papineau 1995, 2003). They argue that if the conscious qualitative property and the neural property are identical, then there is no need to explain how the latter causes or gives rise to the former. It does not cause it, it is it. And thus there is no gap to bridge, and no further explanation is needed. Identities are not the sort of thing that can be explained, since nothing is identical with anything but itself, and it makes no sense to ask why something is identical with itself.