Abstract

In this paper I examine Wittgenstein’s appeals to madness in On Certainty in light of Foucault’s Histoire de la folie. A close look at these works, usually conceived as disparate, belonging to entirely different schools of thought, reveals they actually have much in common. Both can be read as investigations into the grounds of reason, and while they offer quite different and distinct perspectives on the matter, they share some central insights. In both we find that the boundaries of reason are not only vague but also largely founded upon the relations - social in Foucault, socio-linguistic in Wittgenstein - between the reasonable person and the unreasonable person. Both perspectives reveal a curious state of affairs whereby the reasonable person is the one who dominates discourse, and yet, in his claim for reason, remains forever dependent upon the unreasonable person and his rejection. The pressing question triggered by Foucault's account is whether the boundary between reason and unreason is at all necessary. This undermines Wittgenstein’s thesis that this boundary is a matter of logical necessity upon which discourse depends. I flesh this point out in the paper also by examining the differences in Wittgenstein’s and Foucault’s treatments of Descartes’ Meditations. I conclude that Wittgenstein’s criticism of Cartesian skepticism presented in On Certainty loses much of its fortitude once examined in light of Foucault's Histoire de la folie.