Plato died in Athens in 348 or 347 BC, at the age of eighty or eighty-one. According to tradition, he died peacefully in his sleep, at a wedding feast. Diogenes Laertius reports that he was buried in the Academy grounds.
Unlike Socrates, who left no writings, Plato left an extraordinary literary legacy: twenty-five dialogues and thirteen letters (though some letters are disputed). These works would be copied, studied, and debated for the next two millennia.
Immediate influence
The Academy continued under Speusippus, then Xenocrates, then a succession of scholarchs who kept Platonic philosophy alive. Aristotle, though he founded his own school (the Lyceum), remained deeply influenced by Plato even as he criticized him.
Plato's political philosophy shaped Greek and Roman thought. His metaphysics — the Theory of Forms, the realm of eternal truths beyond the physical world — became foundational for later philosophy and theology.
Long-term influence
Neoplatonism (3rd-6th centuries AD) revived and reinterpreted Plato, making him central to late ancient philosophy. Early Christianity absorbed Platonic ideas — the immortal soul, the supremacy of the Good, the distinction between appearance and reality.
During the Renaissance, scholars rediscovered Plato's original texts and saw in them a vision of human dignity and rational inquiry. The Cambridge Platonists, Kant, Hegel, Nietzsche, Whitehead — all engaged with Plato, either building on him or reacting against him.
Alfred North Whitehead famously said that all of Western philosophy is "a series of footnotes to Plato." This is an exaggeration — but only a slight one.
Whether you agree with Plato or reject him, you cannot think seriously about reality, knowledge, justice, or beauty without engaging with the problems he defined.
Why Plato still matters
Plato's questions remain urgent: What is justice? What should we value? How should we organize society? What is knowledge, and how do we get it? Are there truths that hold regardless of opinion or power?
He offers no easy answers. But he teaches a method: question everything, define your terms, follow the argument wherever it leads. This is the heart of philosophy — and it remains as necessary now as it was in 399 BC when Socrates stood trial for doing exactly that.