Full Idea
A physicalist account of conscious experience must explain how it is possible for a physical system to be a conscious subject, but not 'what it is like' for some organism.
Gist of Idea
Physicalism should explain how subjective experience is possible, but not 'what it is like'
Source
comment on Thomas Nagel (What is it like to be a bat? [1974]) by Robert Kirk - Mind and Body §4.2
Book Reference
Kirk,Robert: 'Mind and Body' [Acumen 2003], p.80
A Reaction
You can't entirely evade Nagel's challenge. We are trying to discover the 'neural correlate of consciousness', which will explain why we are conscious, but we also want to know why we experience green for one wavelength, and red for another.