In confrontation with doubt, Descartes realized that he could not be mad; the literary character of Rameau's nephew, however, knew that he was mad. The eighteenth century could not understand the work Rameau's Nephew. But a curious thing happened as the text was written. Unreason reappeared with a new power of interrogation. But the eighteenth century only noticed its social effects. For the first time since the Great Confinement, the madman became a social individual. For the first time, he was questioned. But yet madmen were only caricatures or silhouettes; their status is unsure. By letting madmen back into the light, classical reason admits its closeness to unreason. Reason allowed its double to drift onto the margins. But fear and anxiety were close. People were afraid of being confined. Confinement became a place of evil. A medical fear inspired by moral myth arose. People feared disease spread from houses of confinement. Houses of confinement were seen as sites of corruption and corrupted air, as with leprosy. The old fears about leprosy seemed to synthesize unreason and the medical universe. But the doctor entered the world of unreason as a guardian, not to decide who was mad or sane.
The eighteenth century reform movement aimed to organize and purify the houses of confinement. Morality and medicine tried to defend themselves against the dangers of confinement. The horrors confined in such places were fascinating, as de Sade's work shows. A whole imaginary landscape reappears, created by the great fear inspired by confinement. The classical period confined not only madmen and criminals, but also the fantastic. Fortresses of confinement separated reason from unreason on the surface, but also preserved places where they mixed. Confinement preserved forbidden imagery intact from the sixteenth to the nineteenth century. But in the darkness these images mutated.
In the classical period, awareness of madness and unreason had not separated from each other. Madness nearly disappeared in unreason. The fear of madness grew at the same time as the fear of unreason, so the two reinforced each other. Concern grows that man becomes more delicate as he perfects himself. Nervous diseases are growing. The threat of madness is ever-present. But the fear of madness is accompanied by an analysis of modernity, situating it in historical, social and cultural context. There is a difference between awareness of madness and unreason; from this point, awareness of unreason will become timeless and original, as in Nietzsche, whereas awareness of madness will situate it in historical context. The times of madness and unreason are different.
Foucault discusses madness and liberty. Montesquieu says that there is an English tendency toward suicide, which is brought on by their climate. A political and economic solution is being sought, in which progress and institutions explain madness. Madness is seen by other writers as the result of the liberty enjoyed in England. Liberty alienates man from himself and his world.
Religious belief prepares the ground for madness. It involves the satisfaction or repression of the passions. The organization of the believer's time by priests is beneficial. Old religion is a positive force, but modern religion eventually allows madness to function freely.
Civilization is the milieu suitable for the development of madness. The progress of knowledge allows a mania for study and a dangerous excitement of the mind to develop. Sensibility also detaches men from feeling; a sensibility that is controlled by the demands of social life is dangerous. Novels and theater excite people in a dangerous way. The novel perverts sensibility because it leads the soul into a world of imaginary sensibility.