This paper examines the theory of mixed constitution and the sociological doctrine of anacyclosis in Book VI of Polybius’ Histories. The ideal of a mixed government was popularized by Polybius, who saw the Roman Republic as a manifestation of Aristotle’s theory. Monarchy was embodied by the consuls, the aristocracy by the Senate, and democracy by the elections and great public gatherings of the assemblies. Each institution complements and also checks the others, presumably guaranteeing stability and prosperity. Polybius makes further distinction in the forms of government by including the nefarious counterparts to the ones mentioned above; tyranny, oligarchy, and ochlocrazy. These governments, according to Polybius cycle in a process called...