Polybius on the Roman Constitution, Checks and Balances, and Causes of Decline

In his work The Histories, Polybius told the story of the Roman Republic’s rapid rise to power in the Mediterranean world over the first half of the 2nd Century BCE. Polybius attributed much of Rome’s success to her customs and constitution, particularly to the system of separation of powers with checks and balances, which he believed kept the Republic strong and uncorrupted. However, he also believed that it is a fact of nature that all nations eventually decline. His predictions concerning the decline and fall of the Republic were largely fulfilled within 100 years of his death. In this lecture, I will examine Polybius’ ideas about the cycles of political systems, the strengths of the Roman constitution, and his speculations on the probable causes for the Republic’s future decline and fall. Given Polybius’ influence on Montesquieu and the framers of the United States Constitution, his theories and predictions have particular resonance for modern Americans contemplating the future of our own republic.