Plato · Aristotle
A genuine relationship, not a slogan
The conventional handling of Plato and Aristotle reduces them to a slogan: Plato the idealist, Aristotle the empiricist. The slogan is not useful. Aristotle studied at the Academy for roughly two decades. His writing is a sustained, often critical engagement with Plato; he adopts much of his teacher's vocabulary, refines parts of his argument, and parts company on others. The two are best read together — not as opposites, but as the first long conversation in the Western philosophical tradition.
Where they converge
Both treat philosophy as a way of life and not merely a body of doctrine. Both place virtue (aretē) at the centre of ethics and the character of the citizen at the centre of politics. Both think the human good is something that has to be cultivated, not something a person is born with. Both think the well-lived life requires something more than merely doing what one is told; it requires knowing what is worth doing and why.
Where they part company
The deepest disagreement is over the status of the forms or universals. Plato's middle-period dialogues present the forms as separate intelligible realities; the famous criticism in Aristotle's Metaphysics is that the doctrine of separate forms does not in fact explain the things in the world that it is meant to explain. The Aristotelian alternative — form as immanent in particular things, known by abstraction from experience — is set out across the Metaphysics, the Physics and the psychological and biological works.
The disagreement carries into ethics. The Republic presents justice in the city by way of an analogy with justice in the soul, and proposes philosophic rulers as the city's best ordering. The Nicomachean Ethics and the Politics take a different tack: ethics is a practical science whose conclusions must answer to the specific situations of human life, and politics is the inquiry into which actual constitutions, for which actual peoples, will tend toward the good. Phronēsis — practical wisdom — does more work in Aristotle than it can in the Republic's scheme.
Why both matter for Virtue & Power
The classical tradition is unintelligible without both. The medieval Latin West will be drawn first more to Plato (through Augustine and Neoplatonism) and later, decisively, to Aristotle (through the twelfth- and thirteenth-century translations and the work of Aquinas). The medieval Islamic and Jewish traditions read both seriously and often together. The modern revival of virtue ethics has reached more often for Aristotle; modern political philosophy of nearly every persuasion is still in conversation with the Republic. To read either well is to be reading both.
For the editions and reference works behind this comparison, see our Sources page.