The Glass Delusion and Its History – The Public Domain Review

Three centuries later, Foucault argued that Descartes had not only excluded the glass man from his rationality, but also employed him. “The man who imagines himself to be made of glass is not crazy,” writes Foucault, “for every sleeper can have this image in a dream; but he is angry if, believing that he is made of glass, he thereby comes to the conclusion that he is fragile, that he is in danger of breaking, that he must not touch any object that is too strong, that he must in fact remain motionless, and so on.’ By invalidating the thinking of the glass man, it was established for the first time what valid thinking looked like: “Madness is dispelled, rejected and exposed in all its impossibility from the deepest interiority of thought itself.” Jacques Derrida would object that Descartes had actually done the opposite: by admitting that the dreamer is indistinguishable from the madman, Descartes had made the madman’s condition that of a rational life: ‘reason is crazier than madness.’ Both Foucault and Descartes implicitly agreed that the glassman whom Descartes had tried to discredit had become the hinge on which their debate revolved. But neither Cervantes nor Descartes (nor Foucault or Derrida, for that matter) wrote in detail about the historical origins of the delusion itself. Why glass? Why this material, this century, these patients?