Never before has the inner turmoil of Rousseau's writings been taken so philosophically seriously as in Ernst Cassirer's major study "The Problem of Jean-Jacques Rousseau" from 1932. Cassirer presents the epochal critic of modern civilization and alienation, the revolutionary theorist of the social contract, but also the scrupulous explorer of his own existence, the influential educator, and the lonely melancholic. Cassirer finds the hidden focal point of this colorful cosmos in Rousseau's theory of subjectivity and universal practical reason, which laid the groundwork for Kant to develop the fundamental principles of his moral and legal philosophy a few years later; a thread that Cassirer further pursued in his 1939 study on Kant and Rousseau. Cassirer's works remain of unbroken relevance and vitality.