Hume and the Molyneux Problem

How would Hume have addressed William Molyneux’s question to Locke: would a man born blind but able to distinguish between a sphere and cube by touch, immediately on acquiring sight, distinguish these figures visually? As a central issue in eighteenth-century epistemology and psychology, one would expect Hume to have dealt with it in his Treatise and, like Locke and Berkeley, answered in the negative. After offering a possible reason for Hume’s neglect of this problem, the paper argues that Hume’s focus on the problem of a vacuum and a relational theory of space would have prompted a response more akin to Leibniz than Molyneux. The paper first analyzes Hume’s position, then discusses the central features of Hume’s account of extension. It argues that this account commits Hume to the thesis that both visual and tangible ideas of space are three-dimensional and, if developed, would lead to a positive answer to Molyneux’s question.