Modern commentators trace the emergence of Western philosophy back to Plato. Karl Popper once suggested that Western thought has been Platonic or anti-Platonic but rarely ever non-Platonic, while Alfred North Whitehead famously quipped that the history of Western philosophy has been little more than “footnotes to Plato.”

One reason for his enduring influence is the sheer breadth of Plato’s writing. Across three dozen dialogues, Plato tackles everything from theology, metaphysics, and epistemology to political theory, the nature of love, and the theory of language. Another reason is the undeniable depth of Plato’s thought, which assimilates insights from his predecessors — Parmenides and Pythagoras in particular — while breaking new ground in many of the areas highlighted above.

A third reason, far less remarked upon, is the historical role that Plato’s philosophy has played in attacking democracy. His most influential work, The Republic, is a highly sophisticated argument against the democratic approach to government that had taken shape in Plato’s time. Plato’s uncompromising defense of human inequality has appealed to conservatives ever since.