A Beautiful Mind is a terrible thing to waste. In his adaptation, Ron Howard has dumped most of Sylvia Nasar’s biography of John Nash, the mathematical genius who rebounded from schizophrenia to win a Nobel Prize in 1994. The book is uncompromising, eloquent, complex, ambiguous — who would want to watch something like that? So let’s pretend it was never written, the life never lived. How does the movie stand on its own?

Following up his big Oscar year, Russell Crowe evokes Dustin Hoffman in his depiction of the eccentric Princeton graduate student — let’s call him Brain Man — who stunned the world with his contributions to game theory (demonstrated, with crass cleverness, by the competitive dynamics of a dating bar) but then slipped into paranoia while working for the government during the Cold War. To depict the rarefied demons of mental illness, screenwriter Akiva Goldsman, taking a cue from his Batman and Robin, invents not one sidekick for poor Nash but three: a bumptious roommate named Charles (Paul Bettany), a little girl named Marcee (Vivien Cardone), and a CIA spook named Parcher (Ed Harris, who after playing a mentally ill person in Pollock plays a symptom here). His ego, id (or inner child, probably, since an id is so un-PG-13), and superego, so to speak, these cartoons get as much screen time as Nash’s wife, Alicia (Jennifer Connelly), no doubt because the car chases, gunfights, and phony suspense and sentiment they offer take less thought and imagination than genuine human drama or truth. Schizophrenics, notes a psychiatrist in the movie, are pathologically incapable of recognizing the truth. If so, A Beautiful Mind is schizophrenic.