This dissertation identifies and explains four major contributions of the Laws and related late dialogues to Plato's moral and political philosophy. -/- Chapter 1: I argue that Plato thinks the purpose of laws and other social institutions is the happiness of the city. A happy city is one in which the city's parts, i.e. the citizens, are unified under the rule of intelligence. Unlike the citizens of the Republic, the citizens of the Laws can all share the same true judgments (...) of value, and this unanimity explains the city's unity. Plato thinks that aiming at the city's happiness is justified, moreover, because a unified city contributes to the universe's order. -/- Chapter 2: In the Laws, Plato holds that the sick, poor, ugly, weak, but virtuous are happy, and that health, wealth, beauty, and strength benefit the virtuous but harm the vicious. Only in the Laws does Plato commit himself to all these claims simultaneously, and I explain how the moral psychology of the Laws permits Plato to maintain them coherently. -/- Chapter 3: I argue that, in the Laws, becoming virtuous is the same as becoming like God. Becoming like God does not require escape from the world of change as it does in the Theaetetus, however. Rather, becoming like God requires bringing "measure" or appropriate order to the world of change, especially to those entities over which we have the most control—our own souls. In the Laws, citizens achieve this order as they learn to be just and to understand the nature of reality. -/- Chapter 4: Unlike the Republic and Statesman, the Laws holds that obedience of the citizens to their laws should be effected, if possible, with rational persuasion. I argue that Plato wishes such persuasion to educate the citizens of the reasons for the laws. Understanding the laws' justification is the principal way in which citizens acquire the good judgment necessary for virtue. The city becomes more happy as the citizens progress in virtue, so rational persuasion is a necessary means to the lawgiver's overall aim. (shrink)