Phenomenal transparency and the boundary of cognition

Abstract Phenomenal transparency was once widely believed to be necessary for cognitive extension. Recently, this claim has come under attack, with a new consensus coalescing around the idea that transparency is neither necessary for internal nor extended cognitive processes. We take these recent critiques as an opportunity to refine the concept of transparency relevant for cognitive extension. In particular, we highlight that transparency concerns an agent's employment of a resource – and that employment is compatible with an agent consciously apprehending (or attending to) a resource. This means it is possible for an object to be transparent and opaque to an agent, even at a single moment time. Once we understand transparency in this way, the detractors' claims lose their bite, and existing arguments for transparency's necessity for cognitive extension return to apply with full force.