Constitutional Instability and Plato’s Five Regimes

The past two weeks, I read all of Book VIII of Plato’s Republic, and I have begun researching the philosophical arguments and historical context for his theories. In this section, Plato describes the five types of constitutions — aristocracy (rule by the best), timocracy (rule by the honored), oligarchy (rule by the wealthy), democracy (rule by all), and tyranny (rule by one). Aristocracy is his proposed ideal form of government, which he describes in previous books. Under this system, the guardians choose the best people from the next generation to be the new guardians, the best of whom become the ruling philosopher kings. However, in Book VIII, Plato says such a city will never last forever, as eventually the wrong people will be chosen as guardians. They will value honor over virtue, strength over wisdom or education, and eventually the city will shift to a timocracy. After this, Plato describes four more transformations of government. When rulers become more obsessed with money than honor, the city shifts to an oligarchy. The oligarchic city has so much wealth inequality that the people rise up and create a democracy. These people are so free and willing to let any of their appetites control them that a corrupt, populist leader will rise up as a tyrant. I’ve become especially interested in these transitions and why Plato does not seem to think there is any stable form of government. One key distinction that I noticed is that the aristocracy seems to only be unstable because of the impossibility of perfect implementation, whereas the other forms seem more fundamentally unstable. A problem only arises in the aristocracy when the guardians do not perfectly determine the correct time for births (because of their ignorance of the nuptial number, as I discussed two blog posts again) and do not choose the correct future leaders, but this is a problem of human imperfection rather than fundamental instability. However, the other forms have other problems baked into the system. Socrates says that “τὸ ἄγαν τι ποιεῖν μεγάλην φιλεῖ εἰς τοὐναντίον μεταβολὴν ἀνταποδιδόναι” or “any excess is wont to bring about a corresponding reaction,” such as the wealth inequality in an oligarchy leading to total equality in a democracy. This week, I am trying to learn about Plato’s theory of Forms to better understand these ideas about constitutional instability.