 Any well-worked out epistemology will provide at least the materials for a theory of cognitive development in childhood. Thus according to René Descartes a clear and distinct knowledge of the world can be constructed from resources innate to the human mind (Descartes, PW, 131). John Locke, by contrast, maintains that the human mind begins as a “white paper, void of all characters, without any ideas” (Locke, EHC, 121). On this view all the “materials of reason and knowledge” come from experience. Locke’s denial of the doctrine of innate ideas was, no doubt, directed specifically at Descartes and the Cartesians. But it also implies a rejection of the Platonic doctrine that learning is a recollection of previously known Forms. Few theorists of cognitive development today find either the extreme empiricism of Locke or the strong innatism of Plato or Descartes completely acceptable.