Alan Ryan on Polybius

“Polybius mentions Plato’s theory, but his picture of the transformation of good constitutions into bad is more Aristotelian: the good forms—monarchy, aristocracy, politeia—turn into their bad opposites—tyranny, oligarchy, mob rule. Polybius had no interest in the search for a philosopher-king and was not concerned to explain why perfection could not last forever. Utopia was uninteresting; since it never existed, it could teach no lessons. Polybius knew that the works of man are imperfect; sooner or later even the Roman Empire will decay, probably sooner rather than later. The destruction of Carthage brought tears to Scipio’s eyes, even as he ordered its completion; and Virgil’s Aeneid is surely a reflection on the theme of Troy, Carthage—and Rome? The question was how the Romans had thus far escaped what seemed to be their inevitable fate. They had begun with a botched constitution: they established elected kings with few checks. Nonetheless, their ancient kings had not become tyrants; they had been expelled. Even then a mixed constitution was not instituted by a Roman Lycurgus, and all of a piece, but evolved by trial and error. How had the Romans done it? Prompted by Livy, who himself was much in debt to Polybius, Machiavelli asked just that question.10 The question remains important even after we reject cyclical (indeed any or all) theories of history; states can recover from unpromising beginnings, and it is worth knowing how they do it. It was obvious to Polybius that Rome had done it; his problem was to square the facts with the theory.”

“Polybius's picture of the motors of political change is persuasive if not taken rigidly, and it provides a rationalization of Roman history: leaders who rise by their talents will (at least initially) live like their fellows and arouse no hostility, while those who inherit a throne will separate themselves from everyone else and arouse envy. They will be opposed by men of the upper class affronted by the insolence of their king—or kings, since Polybius knew that Sparta and Rome had been ruled by a collective monarchy. When they are overthrown, their aristocratic supplanters will rule in their stead. That aristocracies degenerate into oligarchies is the most common complaint against aristocratic governments, and often leveled at their modern descendants, the elected aristocrats who occupy the seats of power in the modern democratic world. Readers will find less persuasive Polybius’s claim that when an oligarchy is overturned, democracy invariably follows. He says that the memory of the tyranny of kings will be too fresh in everyone’s mind for there to be a reversal of the cycle from oligarchy to monarchy, but this is empirically unconvincing; it turns the unusual experience of Athens and Rome into a principle. We are all too familiar with situations in which a disgusted public turns to a dictator, though it has to be said in Polybius’s favor that “oligarchy-democracy-dictatorship” is perhaps the most common cycle of all.”