However, Jackson later rejected his argument and embraced physicalism. He notes that Mary obtains knowledge not of color, but of a new intramental state, "seeing color". Also, he notes that Mary might say "wow," and as a mental state affecting the physical, this clashed with his former view of epiphenomenalism. David Lewis' response to this argument, now known as the "ability" argument, is that what Mary really came to know was simply the ability to recognize and identify color sensations to which she had previously not been exposed. Daniel Dennett and others also provide arguments against this notion.