Against the Modern World is the first history of Traditionalism, an influential yet surprisingly little-known twentieth century anti-modernist movement. Involving a number of important, yet often secret, religious groups in the West and Islamic world, it affected mainstream and radical politics in Europe and religious studies in the United States. Emerging from the 'discovery' in the West of non-Western religious writings, at a time in the nineteeth century when progressive intellectuals had lost faith in the ability of Christianity to deliver religious and spiritual truth, it was fuelled by the widespread religious scepticism that followed World War I. It found its voice in Rene Guenon, a French writer who rejected modernity as a dark age, and sought to reconstruct the Perennial Philosophy - the fundamental truth uniting all the world's religions. Mark Sedgwick reveals how this pervasive intellectual movement helped shape major events in twentieth century religious life, politics and scholarship - all the while remaining invisible to outsiders.