Plato and Aristotle on Politics: Justice, Constitutions, and the Limits of Ideal Theory

Plato’s Republic and Aristotle’s Politics represent two of the foundational texts of Western political philosophy. While both philosophers seek to understand justice and the best form of government, their approaches diverge sharply. Plato envisions an ideal state ruled by philosopher-kings, structured around the harmony of classes, and oriented toward the transcendent Form of the Good (Plato, 2003/380 BCE). Aristotle, by contrast, grounds his analysis in empirical observation of constitutions, emphasizing moderation, the rule of law, and the practical conditions of civic life (Aristotle, 1998). This paper compares their political theories, highlighting their agreements and disagreements on justice, education, the role of citizens, and the feasibility of ideal states. It argues that the contrast between Platonic idealism and Aristotelian empiricism has defined the subsequent trajectory of political thought, setting the terms for debates about the relationship between theory and practice (Annas, 1981; Kraut, 2002).