Elisabetta Sassarini

Frank Jackson’s Knowledge Argument claims that Mary—a neuroscientist who knows all the physical facts about color perception but has never seen color—learns something new when she sees red, posing a challenge to physicalism. While physicalists deny that Mary acquires knowledge of new facts, they must still explain her apparent epistemic progress. I argue that the intuition that Mary gains new knowledge upon seeing red stems from the alleged opacity of propositional attitude ascriptions—the same phenomenon underlying Frege puzzles.

This paper examines an argument by Schaffer (2017) that aims to prove how, contrary to what many philosophers hold, there is no special explanatory gap occurring in the connection between the physical and the phenomenal. This is because a gap of the same kind can be found in every connection between a more fundamental and a less fundamental level of reality. These gaps lurk everywhere in nature. For Schaffer, they can be bridged by means of substantive metaphysical principles such as grounding principles. He thus puts forward a version of grounding-based physicalism, which is supposed to provide this kind of substantive bridge principle. My main contention is as follows: even if Schaffer’s argument indeed proves the existence of a gap in every connection between fundamental and derivative entities, and such gaps can be bridged by means of grounding principles, a different gap remains open in the psycho-physical connection.