The ecclesiastical organizations reflected the underlying tendency toward broader social interpretation of the duties of the community. The controversy between science and religion following the publication of Darwin's epoch-making theories of evolution attracted wide-spread interest during the early years of this period, and much of the intellectual energy of the day was consumed in this struggle. The Socialist theory of the function of the state appeared early in the United States and was a considerable factor in public thought, especially during the last twenty-five years. Socialism in the United States has passed through a series of phases. At the outset, the Liberal Republicans, the Greenbackers, the liberal reformers and the single taxers absorbed the interest and attention of many of the socialists and various combinations were made. Socialism opposes the theory of anarchy that there can be liberty without law, sustained by force, and is hostile to the communistic theory of industrial self-government by groups, independent of state control.