This study traces a persistent connection between the image of disease and the concept of difference in Plato’s Gorgias, Phaedo, and Timaeus. Whether the disease occurs in the body, soul, city, or cosmos, it always signals an unassimilated difference that is critical to the argument. I argue that Plato represents—and induces—diseases of difference in order to produce philosophers, skilled in the art of differentiation. Because his dialogues intensify rather than cure difference, his philosophy is better characterized as a “higher pathology” than a form of therapy. An introductory section on Sophist lays out the main features of the concept of difference-in-itself and concisely presents its connection to disease. The main chapters examine th...