Foucault was the author of Madness and Civilisation. (PROSE: The Book of the War)
He was one of many philosophers F.I.D.O discussed with Graelyn Scythes during their near-daily walks during the seventeen years Graelyn spent in Auteur's Town. According to F.I.D.O, Foucault once "wrote that madness, in the 18th century, (…) was often used to stigmatize those who were unwanted by society" — "poor, sick, and those whose own thoughts fell outside the social norms". This proved that "knowledge in itself [wasn't] a pure virtue, because knowledge [was] shaped by the existing powers who controlled it to gain more [power]". These observations were of course fairly relevant to Graelyn's current situation, trapped in a false reality constructed by Auteur with memories of her true lifetime resurfacing as dreams which Auteur tried to construe as unhealthy manifestations of her loneliness. (PROSE: White Canvas)