 This claim is intended as a thesis in the metaphysics of mind, but it functions equally well as a thesis about the epistemic status of artifacts. In Otto’s case—and it is clear Clark and Chalmers intend it not as an exceptional case, but as a particularly striking instance of a commonplace one—the notebook is cognitive in its own right. It is an essential element of a widely individuated cognitive process, not a cognitively neutral tool used by an encapsulated cognizer. Critics of the extended mind thesis have been, if not legion, extremely persistent (Menary 2010). But they have focused mostly on the disconcerting metaphysical implications, rather than on the equally significant implications about cognition. John Sutton (2010) anticipates the metaphysical tendentiousness of the Parity Principle giving way to the important work of understanding the complementarity of inner and outer processes in cognition which is highlighted by the extended mind thesis. Individuating cognitive processes widely, so that the unit of investigation is not the mind/brain but cognitive systems comprising tightly coupled artifacts, people, built environments and natural environments, is a viable project in its own right, and one that was underway in many quarters before the extended mind thesis was proposed.