Sociopaths have haunted fiction since fiction began, and no wonder. Sociopathy is civilization's greatest challenge. Richard III and Iago; Raskolnikov, Kurtz, Willie Stark, and Humbert Humbert; J.R. Ewing, Frank Underwood, and even HAL 9000. How do we understand the narcissist, the demagogue, the liar, the manipulator, the person without scruples or conscience? The creative imagination can probe dark places that psychology and medicine can't reach. So I am not being cute when I say that Star Trek is a source of insight into the universe of President Donald Trump.

Actually, Star Trek—the original television series, at least—is a source of insight into many things. The show, which aired for three seasons, from 1966 to 1969, was ahead of its time and breathtakingly ambitious. Amid the wasteland of 1960s television, it explored genetic engineering, automated warfare, the divided soul, the qualities of leadership, and much more.

Its leading obsession, however, was sociopathy, which in Star Trek's world—as in our own—is an ever-present danger. Why is the sociopath so charismatic? Why are good people vulnerable to his machinations? Why do sociopathic leaders rise to power throughout history, despite the toll they inflict? How can their excesses and influence be contained?

In the second-season episode "Amok Time" (1967), the show delivers a warning. Reason and dispassion are weak reeds, and they are weakest among those who presume them to be strong. Spock, the ultra-rational Vulcan, turns out to harbor deep tribal impulses, which break through all the more violently for having been suppressed. He proves capable of the ultimate sociopathic act, murdering his commander and best friend.