Case study evidence for an irreducible form of knowing how to: An argument against a reductive epistemology

Over recent years, there has been a resurgence of interest in arguments favouring intellectualism-the view that Ryle's epistemic distinction is invalid because knowing how is in fact nothing but a species of knowing that. The aim of this paper is to challenge intellectualism by introducing empirical evidence supporting a form of knowing how that resists such a reduction. In presenting a form of visuomotor pathology known as visual agnosia, I argue that certain actions performed by patient DF can be distinguished from a mere physical ability because they are (1) intentional and (2) knowledge-based; yet these actions fail to satisfy the criteria for propositional knowledge. It is therefore my contention that there exists a form of intentional action that not only constitutes a genuine claim to knowledge but, in being irreducible to knowing that, resists the intellectualist argument for exhaustive epistemic reduction.