In “The Boy Who Loved Batman,” Uslan lays out an exhaustive list of his concerns about casting Keaton as Batman, along with every single pre-prepared response from Burton. In reply to the main concern that “Michael Keaton is a comedian,” and “not a serious actor capable of being a serious Batman,” Burton simply argued the contrary, even setting up a screening of “Clean and Sober” so that Uslan could witness the star’s dramatic chops firsthand.
Next up was the “problem” of the 5-foot 9-inch Keaton’s stature and physicality, which Burton evidently “knew how to cheat” during filming and which would be enhanced by musculature that was “carved into the costume.” But you can’t necessarily cheat the fact that, as Uslan put it, “Keaton doesn’t have a square jaw like Batman does.” Fortunately, for Burton, that simply wasn’t the problem his producer thought it was, and the response came tersely: “Michael, a square jaw does NOT a Batman make.”
That last point was essentially a way of highlighting that, in his trenchant opposition to casting Keaton as Batman, Uslan had strayed from his guiding principle of making something unconventional — of reinventing Batman. Thankfully, Burton’s confident responses eventually won over the producer, who summed it up like this:
“[Burton] knew that with Michael Keaton, he could paint a picture of a Bruce Wayne so driven to the breaking point that audiences would say, ‘THAT’S a guy who would put on a Bat-Suit to fight crime!’ And that alone sums up the genius of Tim Burton.”