Abstract

Consciousness researchers standardly rely on their subjects’ verbal reports to ascertain which conscious states they are in. What justifies this reliance on verbal reports? Does it comport with the third-person approach characteristic of science, or does it ultimately appeal to first-person knowledge of consciousness? If first-person knowledge is required, does this pass scientific muster? Several attempts to rationalize the reliance on verbal reports are considered, beginning with attempts to define consciousness via the higher-order thought approach and functionalism. These approaches are either problematic in their own right, or ultimately based on a first-person access to consciousness. A third approach assumes that scientists can trust verbal reports because subjects reliably monitor or ‘introspect’ their conscious states. This raises the question of whether the reliability of introspection can be validated by independent criteria. Merikle's attempts to validate this reliability are shown to involve some unavoidable circularity. It is conjectured that scientists’ reliance on their subjects’ verbal reports tacitly appeals to their own introspective reliability, which is not independently validatable. Some epistemologists might conclude that this renders scientists’ conclusions about conscious states unjustified, but I argue that this does not contravene the constraints of a proper epistemology.