With Trump, it seems necessary to retrieve the rich conceptual vocabulary of psychoanalysis. His aberrant behavior seems to demand deeper understanding. Why does he feel such a need to belittle and humiliate anyone who challenges his primacy, be it Jeb Bush, Hillary Clinton, Mitch McConnell or Kim Jong Un? What explains his habit of not simply denying criticisms made of him, but completely inverting them—to claim, for example, that he’s “the least racist person” of all, or that it was Hillary Clinton who colluded with the Russians in the 2016 election? How can he, without apparent awareness, embrace people one day, turn on them with fury the next, and then perhaps welcome them again as if nothing happened? These actions go beyond standard political spin and hypocrisy, beyond most politician’s self-aggrandizing or inconsistent behavior. Perceptive and psychologically conversant analysts should be able to contribute to our understanding of these sorts of patterns where political science and journalism cannot.

But there’s also a risk of repeating the errors of the Goldwater- and Nixon-era psychologists, who too often filtered their readings of those men’s personality through their own politics and failed to notice their high-level functioning in many areas. Trump, too, for all his juvenile, obnoxious and cruel antics, is a successful businessman and politician, one who functions in his job, however erratically. Moreover, as the psychiatrist Richard Friedman has argued, the character traits that make him outrageous aren’t necessarily symptoms of any deep psychological disorder; they may simply be the human traits of selfishness, pettiness, nastiness and shamelessness, in very high doses. Labeling Trump unstable or deranged does nothing to help us understand why he acts as he does. On the other hand, the dormant tradition of psychobiography, if practiced with due modesty and sensitivity, just might.