It may rank as the most notorious single claim in the history of philosophy: “Until philosophers rule as kings in their cities,” Socrates casually tells his young friend Glaucon, “or those who are nowadays called kings and leading men become genuine and adequate philosophers ... cities will have no rest from evils.”
This startling assertion comes some distance into Plato’s dialogue Republic — at 473d, in the conventional pagination — but it introduces the work’s main character, the so-called philosopher-king. Socrates has defined the philosopher as not just a lover of wisdom, but as a special kind of seer, someone dedicated to knowledge truth with a capital “T.” It follows that this exceptional fellow is the sole person fit to rule any city, including the ideal city he is sketching for his interlocutors.
We might immediately wonder: does he, or Plato, seriously mean this? There is a good deal of destabilizing evidence. Socrates himself says a couple of times that he hesitates to make the claim, knowing how odd it will sound. Also, in the part of the quotation I elided above, he notes that existing philosophers, assuming there are any, would probably have to be forced to rule.
Elsewhere in the dialogue there are scattered clues that the whole ideal city setup, including the philosophically-minded ruler, is a veiled warning that thinkers ought to steer well clear of politics. Force and deception will be necessary to turn an unruly populace toward the truth, he notes, without mentioning that this seems to set up a performative contraction: how can a loyal servant of the truth use deception as means even to a good end?
Additionally, in a blood-chilling passage, Socrates drops a hint that no ideal city will be possible without first getting rid of everyone over the age of 10. Call it the Clean-Slate Premise. Ouch.
Despite all this, Plato will be forever associated with the idea of the philosopher-king, and indeed the notion of a perfectly enlightened ruler is a specter that haunts all politics. Every elected official, from the lowliest alderman to the president of a major nation, is doomed to measured against, and fall short of, this towering ideal of perfect knowledge in the service of justice.
At the same time, the idea of a philosopher-king sounds a different kind of warning: not for philosophers to avoid politics, but for citizens to be on guard when any self-styled thinker or social engineer gets his hands on the reins of power. “Quis custodiet ipsos custodes?” the Roman poet Juvenal wondered, in his Satires — “Who guards the guardians?” (Or, if you are an Alan Moore fan, “Who watches the Watchmen?”)
It is a very good question, especially when those guardians come armed with some big-plan ideology, a few willing henchmen and a taste for utopian social reform. Commitment to the truth sounds like a good thing, but experience shows that implementing an ideal social scheme gets messy all too quickly.
Plato himself was wary of political power. The treatment of his philosophical master, Socrates, under both oligarchy and democracy, was not encouraging; it was the latter form of rule that led to the frame-up trial which sentenced Socrates to execution by hemlock, which goes some distance to explaining the strong anti-democratic flavor of Plato’s thought.
Plato’s own attempt to mold Dionysius the Younger of Syracuse into a sort of philosopher-king was an abject failure. The youthful tyrant was addicted to luxury and the indulgence of whims, and found his Greek visitor’s epistemological advice tiresome.