In “City Lights,” [the tramp’s] only friendships are with people who don’t or can’t see him: with a drunken millionaire who doesn’t recognize him when he sobers up, and with a blind flower girl. His shabby appearance sets him apart and cues people to avoid and stereotype him; a tramp is not … one of us. Unlike the Keaton characters, who have jobs and participate eagerly in society, the Tramp is an outcast, an onlooker, a loner.

That’s what makes his relationship with the flower girl (Virginia Cherrill) so poignant; does she accept and treasure him only because she can’t see what he looks like? (Her grandmother, who would no doubt warn her away from him, is never at home when the Tramp calls.) The last scene of “City Lights” is justly famous as one of the great emotional moments in the movies; the girl, whose sight has been restored by an operation paid for by the Tramp, now sees him as a bum—but smiles at him anyway…