Abstract
In Plato's Laws, the Athenian Visitor says that the best constitution is a mixture of monarchy and democracy. This is the theoretical basis for the institutions of Magnesia, and it helps the citizens to become virtuous. But what is meant by ‘monarchy’ and ‘democracy’, and how are they mixed? I argue that the fundamental relations in Plato's discussion of constitutions are those of authority and equality. These principles are centrally about the extent to which citizens submit to the judgment of an authority and the extent to which they decide for themselves respectively—the extent to which they are ruled by themselves or ruled by another. The institutions of Magnesia reflect these principles in practice and provide a more nuanced way to understand Plato’s assessment of democratic institutions.