Contemporary social theory and natural law : Jurgen Habermas -- A natural-law critique of modern social theory : Karl Lowith, Leo Strauss and Eric Voegelin -- Natural law and the question of universalism -- Modern natural law I : Hobbes and Rousseau on the state of nature and social life -- Modern natural law II : Kant and Hegel on proceduralism and ethical life -- Classical social theory I : Marx, Tonnies and Durkheim on alienation, community and society -- Classical social theory II : Simmel and Weber on the universality of sociability and reasonableness -- Social theory as the natural law of 'artificial' social relations.