Leo Tolstoy, Francisco Ferrer, and other radical critics of the modern state, for example, developed an anarchist theory of education in the late nineteenth century that led to the founding of a vibrant “modern school” movement in the years before World War One. A. S. Neill built his freedom based Summerhill School a few years later on the basis of a psychological, rather than explicitly political, interest in freedom. In the 1960s, the rise of student activism and a radical counterculture created a surge of interest in both the psychological and political aspects of freedom, resulting in a “free school” movement that at its peak included nearly a thousand schools across the U.S. Neill’s book Summerhill was a best seller, and other articulate critics of mainstream schooling, including Paul Goodman, George Dennison, Ivan Illich, and John Holt, also wrote boldly and passionately about freedom in learning.