The knowledge argument challenges physicalism—the view that the world is entirely physical—by claiming there are facts about consciousness not deducible from complete physical truths. Frank Jackson, who originally formulated the argument, later rejected it, arguing that sensory experience should be understood as representationalism (or intentionalism), where phenomenal states are merely representational states. This chapter contends that Jackson's representationalist response fails. Physicalists still face a representationalist version of the knowledge argument that retains the original's force; reformulating the challenge in representationalist terms does little to help physicalists answer it.
This book examines the nature of consciousness and its relationship to brain processes, focusing on phenomenal consciousness—what it is like to have an experience. A central controversy is whether physicalism (the view that the mind is physical) can account for consciousness. The discussion centers on Frank Jackson's thought experiment of Mary, a scientist who knows all physical facts about color vision while confined to a black-and-white room. Intuitively, Mary learns something new when she first sees color, which seems to challenge physicalism. The book explores whether this challenge can be defused by appealing to how phenomenal concepts and knowledge work, or whether the problem persists at the level of those concepts themselves.