Paris qui dort reveals aspects of the director which tend to get buried in the genial exuberance of his more well-known sound movies. It is quite explicitly a film about film, about the joy and possibilities of handling a medium which still seems fresh…. Paris is the monuments of the Second Empire and the International Exhibitions celebrating the progress of technology—but also a city transformed by the magical properties of the camera lens. The Eiffel Tower in close-up, viewed section by section, ceases to be the symbol of thrusting commercialism and becomes a pattern of criss-cross lines, an inexhaustible adult playground. Material objects, like clocks in the street or a radio loudspeaker, are seen in unfamiliar perspectives, and so seem to take on an altogether new significance. But what really accounts for Clair's excitement is that these things can be presented in an added dimension, that of the flow of time…. The story itself is banal and of no interest whatsoever, though plot occasionally intrudes, as when Clair maintains a shot of his characters talking without explanatory titles or, towards the end, when his technical resources begin to dry up and the style of the film becomes anecdotal…. But it is the director's delight in the technical possibilities of the medium that carries this film: it is easy to see why Clair leaped into sound at the first possible opportunity, and it is understandable that after seeing Paris qui dort Dziga Vertov was in despair at having been pre-empted. (pp. 208-09)
Jill Forbes, "'Paris qui dort' ('The Crazy Ray')," in Monthly Film Bulletin (copyright © The British Film Institute, 1975), Vol. 42, No. 500, September, 1975, pp. 208-09.