  In developing their insights, feminist epistemologists have addressed the influence on knowledge of the social situations of knowers. Situatedness cannot be just a matter of the social positioning of knowers, however, or of their histories or cultures. What we know is modulated by how we acquire the elements of knowledge, and these processes are shaped by the condition of the body as well as by social conditions. Cognitive skills are expressions of development in various areas of the brain, which in turn is responsive to the rest of the body. We therefore may expect that people with disabilities, whose bodies diverge from the species-typical kind, also sometimes will develop cognitive approaches and abilities that differ from most other people's. Parenthetically, in one of the exceedingly rare instances of a philosopher treating an impairment as something other than a deficit, the 18th century experimentalist philosopher Denis Diderot investigated blind people's ways of knowing (Diderot 1999 [1749], Curran 2013). Taking a stance that resembles, if not prefigures, recent feminist criticisms of Descartes, Diderot, in his “Letter on the Blind for the Use of Those Who See,” describes how blind people know about the world to show the short-comings of Cartesian over-reliance on metaphors that associate reason with light or sight and Cartesian reliance on visual rather than tactile ways of knowing.