A beautiful movie star is cast in a beloved story. The character is fictional—she isn’t even fully human. Nonetheless, activists and purists insist that the actor is the wrong race. I’m speaking of Scarlett Johansson in Ghost in the Shell, the 2017 film adaptation of a popular Japanese manga series. Critics accused the movie’s creators of “whitewashing” the heroine, a cyborg whose physical form is entirely prosthetic and whose race and gender are, in fact, mutable.