Bob Fosse and Julian Barry are singularly unsuccessful at suggesting the complexity beneath the masks of [Lenny Bruce in Lenny]. Where the camp extravagance of Cabaret was a fitting metaphor for the theatricality that both masked and exaggerated the incipient frenzy of Nazi Germany, Fosse's staging of Lenny at all times serves to obscure his subject. Lenny's wife, mother and agent (themselves put across in unnuanced, stereotypic roles) are interviewed in the present, and at every point in Lenny's career Fosse cuts back for their view of events—a technique guaranteed to flatten out the film by showing the comedian who insisted on speaking for himself (down to the final, self-destructive obsessiveness with which he pored over and expounded on his trial transcripts) through the eyes of less articulate observers…. Although writer and director recognise that Bruce was obsessed with the tyranny of social stereotypes, they fail to convey his struggle to explode those stereotypes through a mastery of original juxtaposition, a painful self-analysis turned outwards upon an embarrassed, enraged and fascinated audience. By focusing on Bruce's use of four-letter words, and the fear this generated in the late Fifties and early Sixties, the film-makers obscure the fact that if Bruce were around today he would still be outrageous, because he would find ways to be uncomfortable with himself and his audience…. When the time comes for breakdown, with the half-clothed comedian wandering on to the stage and losing the thread of what he is saying in a fog of drugs and fatigue, Fosse's presentation is still too remote and unaccented for the moment to register as anything but another 'shtick'. The shuttered look of the film, its endless close-ups and staccato style, suggest a stage-play insufficiently adapted for the screen—or perhaps an extended metaphor to the effect that Lenny was always on as a performer, his life always a blend of the public and the private. A more constructive approach might have been to allow for a greater variety of public and private moments, to incorporate the sense that when Lenny made his appearances the stage was too small to hold him and that the boundaries between the self and the audience, the conventional and the obscene, were always being called into question. (p. 110)
Caroline Lewis, "'Lenny'," in Monthly Film Bulletin (copyright © The British Film Institute, 1975), Vol. 42, No. 496, May, 1975, pp. 109-10.