A meek millionaire masquerades as a boxing star to win a girl's heart.
Although one could argue that it goes back even further, since at least William Hazlitt's essay The Fight (1829), boxing has existed in the cultural imagination as the final arbiter of disputes between gentlemen; the crucible of the modern man and the courtroom for the mores of Western masculinity. That Keaton essentially refuses to fight on boxing's own terms is, therefore, of course, rather fitting.
