For Polybius, the function of politics is not to create unanimity, but rather to preserve liberty through stability. This idea is evident in his praise of the Spartan constitution, where Polybius notes that Sparta enjoyed a “lasting heritage of freedom.” 22 Polybius asserted that anacyclosis, with its constant gravitation towards despotism, is detrimental to liberty. Thus it is necessary that the cycle be halted and stability maintained.

How did the Romans preserve their liberty? One might argue that the Romans were made great by their leaders who displayed great personal and civic virtue. There are many examples throughout Roman history of selflessly dedicated and brave leaders, such as Cincinnatus, who gave up absolute power for a simple agrarian life. 23 However, this was not the reason that Rome succeeded. Polybius did not believe that virtue alone was enough to engender a stable and free society. 24 He disregards Athens, rejecting it as an unhelpful model to follow precisely because its moments of greatness were achieved by great men. 25 Shortly after these great men perished or were ousted, Athens, according to Polybius, collapsed back into mediocrity, confusion and destitution. 26

Another issue for Polybius was that human nature is not particularly malleable. Political theory has to adapt to human nature, not vice versa. 27 Rather than hoping blindly for virtuous leadership which was not guaranteed, Polybius firmly believed in reliance upon good rules and institutions to preserve an orderly liberty.

If humans are, as Polybius theorized, self‐​interested animals driven by both fear and sympathy, the solution must be to institutionalize fear in order to promote sympathy. Instead of attempting to eliminate social conflict altogether, Polybius proposed that humans should aim to make conflict productive and useful. Fear can be institutionalized and conflict can be made productive by the combination of the three simple forms of government, i.e. monarchy, aristocracy and democracy.

In another radical move for his time, Polybius rejected the solution of a mixed constitution. Polybius never uses the word “mixed.” Instead, he uses the words “composition,” “arrangement,” “balance” and “equilibrium.” Polybius’s ideal political order is not mixed like the ingredients in a cake are mixed into a single homogenous entity. On the contrary; each piece is separate and distinct and has a different role. 28 This concept of the separation of power is the key to the success of Rome, which Polybius describes as having dominion over almost the entire world. 29