Andy Warhol's films conceal their art exactly as his paintings do. The apparently sloppy and unedited is fascinating. What holds his work together in both media is the absolute control Andy Warhol has over his own sensibility—a sensibility as sweet and tough, as childish and commercial, as innocent and chic, as anything in our culture. Andy Warhol's eight hour Sleep movie must be infuriating to the impatient or the nervous or to those so busy they cannot allow the eye and the mind to adjust to a quieter, flowing sense of time. What appears boring is the elimination of incident, accident, story, sound and the moving camera…. The slightest variation becomes an event, something on which we can focus our attention. As less and less happens on the screen, we become satisfied with almost nothing and find the slightest shift in the body of the sleeper or the least movement of the camera interesting enough. The movie is not so much about sleep as it is about our capacity to see possibilities of an aspect of film carried to its logical conclusion reductio ad absurdum to some, indicating a new awareness to others. Andy Warhol wants to keep his editing to an absolute minimum and allow the camera and the subject to do the work. This of course cannot deny the special qualities of his personality; for it is Andy Warhol that holds the camera and it is through his eyes that we see the scene…. Andy Warhol's film, in which we are constantly aware of the filmic process, sometimes even seeing the frames that end the reels, frames that any sophisticated movie maker would edit out, makes us aware of exactly the limitations and qualities of film itself. A more incident-filled story would draw our attention from the fact that we are seeing a film. Sleep, one of Andy Warhol's first movies, is an indication of what he will soon be able to do: make content-less movies that are exactly filmed still-lifes with the minimum of motion necessary to retain the interested attention of the unprejudiced viewer.
Henry Geldzahler, "Some Notes on 'Sleep'," in Film Culture (copyright 1964 by Film Culture), No. 32, Spring, 1964, p. 13.