'Freud liked to associate the system-building of paranoia with philosophy: "a paranoiac delusion is a caricature of a philosophical system," he writes in Totem and Taboo (1913). Did he sense that the analogy might run the other way too? Might the systematizing of madness in psychoanalysis be a defense against madness? There is a paranoid dimension in much postwar French philosophy as well – the alienation of the gaze in Sartre and Lacan, the power of surveillance in Foucault, and so on but – but the stake is different. As suggested above, perhaps the very critique of the subject in such philosophy is also a secret mission to rescue it. As Leo Bersani comments: "In paranoia, the primary function of the enemy is to provide a definition of the real that make paranoia necessary. We must therefore begin to suspect the paranoid structure itself as a device by which consciousness maintains the polarity of self and non self, thus preserving the concept of identity."'

from 'Blinded Insights: On the Modernist Reception of the Art of the Mentally Ill' by Hal Foster