“Let’s hear about our constitution,” said the Romans. “You said it was unique. What is so special about it?”
Roman SPQR banner (Creative Commons Attribution 3.0 Unported license photo by Ssolbergj)
A good constitution was essential to a state’s success, and Rome came up with just the right recipe for one: a little kingship, a little aristocracy, and a little democracy.
Polybius says there is a cycle to the forms of government (anacyclosis).
MONARCHY is the first to appear everywhere.
When monarchy acts morally and justly it becomes KINGSHIP.
In time, kingship deteriorates and becomes TYRANNY; after which “the best” drive out the king and set up an ARISTOCRACY; which, corrupted, becomes an OLIGARCHY.
When THAT corrupts, the people rise up, drive out the oligarchs, and proclaim a DEMOCRACY. Which ends, willy-nilly, in ANARCHY. End of cycle.
The new one begins when a monarch comes to save the state. If he is wise and just he will become a king; and so on.
Aeneas and Family escape from Troy by Barocci (public domain photo)
“You Romans were able to break this cycle,” Polybius told them. “Right when oligarchy was about to change into democracy, you interposed a mixed constitution and so stopped the wheel and saved the state from corruption. You balanced the three elements of the state (the consuls, or royal element; the Senate, or aristocratic element; and the populace, or democratic element) so perfectly that a Greek looking at the constitution would not be able to tell you what kind it is. In all of history [until Polybius' time, i.e. 140 BC] only you Romans were wise enough to keep yourselves from destruction, mainly by a unique ability to innovate and to adapt to changing circumstances. None of the Greek states have ever been able to do that except Sparta. And Spartans didn’t discover their mixed constitution—it was given to them by Lycurgus.”