Bats, Brain Scientists, and the Limitations of Introspection

Abstract

Thomas Nagel and Frank Jackson have advanced influential arguments designed to foil any materialist attempt to account for the mental.' These socalled knowledge arguments assume that if materialism is true, someone who possesses complete physical knowledge will know every fact about mental states there is to know. Thus, because there are facts about mental states that will not be known by someone who possesses complete physical knowledge but has never enjoyed certain experiences, it follows that materialist accounts of the mental are inadequate. In response, defenders of materialism have generated counterarguments of several kinds. In my view, no materialist strategy has so far been successful, but nonetheless, further development will vindicate one of them. Early resistance to the knowledge arguments aimed to show that what distinguishes a subject who has had certain sensory experiences from someone who is physically omniscient but has never had them is not factual knowledge, but merely an ability, such as an ability to imagine, recognize, or remember,2 or an ability to apply a concept,3 and that hence, there is no fact about mental states that eludes a materialist account. The decisive issue for this first strategy is whether having an ability of the sort in question nevertheless involves possessing factual knowledge about certain phenomenal features of mental states, factual knowledge lacked by the physically omni-