"It was while I was studying the origins of clinical medicine. I had been planning a study of hospital architecture in the second half of the eighteenth century, when the great movement for the reform of medical institutions was getting under way. I wanted to find out how the medical gaze was institutionalised, how it was effectively inscribed in social space, how the new form of the hospital was at once the effect and the support of a new type of gaze. In examining the series of different architectural projects which followed the second fire at the Hotel-Dieu in 1772, I noticed how the whole problem of visibility of bodies, individuals and things, under a system of centralised observation, was one of their most constant directing principles. In the case of the hospitals this general problem involves a further difficulty: it was necessary to avoid undue contact, contagion, physical proximity and overcrowding, while at the same time ensuring ventilation and circulation of air, at once dividing space up and keeping it open, ensuring a surveillance which would be both global and individualising while at the same time carefully separating the individuals under observation. For some time I thought all these problems were specific to eighteenth-century medicine and its beliefs.
Then while studying the problems of the penal system, I noticed that all the great projects for re-organising the prisons (which date, incidently, from a slightly later period, the first half of the nineteenth century) take up this same theme, but accompanied this time by the almost invariable reference to Bentham. There was scarcely a text or a proposal about the prisons which didn't mention Bentham's 'device' - the 'Panopticon'
The principle was this. A perimeter building in the form of a ring. At the center of this, a tower, pierced by large windows opening on to the inner face of the ring. The outer building is divided into cells each of which traverses the whole thickness of the building. These cells have two windows, one opening on to the inside, facing the windows of the central tower, the other, outer one allowing daylight to pass through the whole cell. All that is then needed is to put an overseer in the tower and place in each of the cells a lunatic, a patient, a convict, or a schoolboy. The back lighting enables one to pick out from the central tower the little captive silhouettes in the ring of cells. In short, the principle of the dungeon is reversed; daylight and the overseer's gaze capture the inmate more effectively than darkness, which afforded after all a sort of protection.
... We are talking about two things here: the gaze and interiorisation. And isn't it basically the problem of the cost of power? In reality power is only exercised at a cost. Obviously, there is an economic cost, and Bentham talks about this. How many overseers will the Panopticon need? How much will the machine then cost to run? But there is also a specifically political cost. If you are too violent, you risk provoking revolts...In contrast to that you have the system of surveillance, which on the contrary involves very little expense. There is no need for arms, physical violence, material constraints. Just a gaze. An inspecting gaze, a gaze which each individual under its weight will end by interiorisation to the point that he is his own overseer, each individual thus exercizing this surveillance over, and against, himself. A superb formula: power exercised continuously and for what turns out to be minimal cost."