The Cogito and the Social Dimension of Self-Knowledge Claude Buffier

This chapter examines Buffier’s critique of Descartes’s cogito argument to show that for him self-knowledge has an important social dimension. This is not merely so because qua bodily existence humans integrate into a world where they meet others in their social interactions and, therefore, need to step beyond the inner sphere of their own thoughts to know about their place among them. What is central to the argument presented here is the idea that knowing oneself as a thinking thing requires knowing that one is capable of rational thought. For Buffier, this kind of knowledge requires the self to locate its own practice of thought among people who are cognitively similar. Common sense provides this kind of knowledge and thus turns into an important source of self-knowledge. More generally, Buffier’s account offers two related insights: 1) that self-knowledge remains rather limited when based on the survey of one’s inner thoughts; and 2) that norms of rationality are constructed insofar as they depend on commonly accepted ways of practicing thought.