 Another way to understand phenomenal concepts is as a species of indexical concepts. For instance, Perry (2001) argues that Mary’s new knowledge after release does not pose a problem to physicalism any more than indexical thoughts like “I am a philosopher” or “today is Sunday” (for a defense of this claim see also McMullen 1985). Perry treats Mary’s new knowledge as a particular case of demonstrative belief (and he proposes an account of Mary’s new beliefs after release in terms of his theory of token-reflexive thoughts). After release, when seeing the sky, Mary may think “Oh, so having blue experiences is like this” where “this” refers to a physical property (the phenomenal character) of her present color experience. She could not have had a demonstrative belief of this kind before release. But, again, the fact that makes the thought true is simply the fact that blue experiences have the particular physical property at issue. Therefore, she does not learn any new fact.