German Idealism emerged in 1781, with the publication of Kant's Critique of Pure Reason, and ended fifty years later, with Hegel's death. The intervening half-century was without question one of the most important and influential in the history of philosophy. The thinkers of this period, and the themes they developed, revolutionized every area of philosophy, and had an impact that continues to be felt across the humanities and social sciences. Kant, Fichte, Schelling and Hegel – the four most important German Idealists – paved the way for Marx and Kierkegaard, phenomenology and existentialism, critical theory and poststructuralism, and in doing so left a mark that remains highly visible in contemporary social and political theory, religious studies and aesthetics. Reactions to German Idealism, especially those of the neo-Kantians, logical positivists and Bertrand Russell, were also instrumental in the founding of analytic philosophy, which today reveals and benefits from an increasingly sophisticated appreciation of the European philosophical tradition. German Idealism thus lies at the root of both continental and Anglo-American philosophy, and without it there could have been neither the sharp schism between the two that defined the discipline for much of the twentieth century, nor the resources that sustain current hopes of understanding and overcoming this unproductive intellectual sectarianism.