An early French sociologist who travelled to the United States between 1831 and 1832 to observe democracy at work. His classic work Democracy in America (1835–40) identifies within democracies a tension between equality and liberty which cannot easily be reconciled. Since democracy tends to undermine hierarchy, it discourages the formation of intermediate groupings between the individual and society, and therefore promotes tendencies towards individualism and centralization which, if unchecked, will result in an authoritarian state. This proposition was illustrated in a systematic comparison of France and the United States. The post-revolutionary history of the former country revealed the dangers of attempting to impose equality without first establishing the liberty of self-government: administrative centralism fostered revolutionary despotism. In the case of the United States, the well-entrenched constitutional principle of federalism provided for a multiplicity of intermediate voluntary associations, and a decentralized mode of government to which people had ready access, and in which they could participate. In both cases, however, Tocqueville warned against the ‘tyranny of the majority’, by which ‘every citizen, being assimilated to all the rest, is lost in the crowd’. His work is thus the starting-point for many debates about the nature of mass society (including, for example, D. Reisman 's The Lonely Crowd, 1950, and R. Bellah 's Habits of the Heart, 1985).