Throughout this book I shall use the term ‘theory’ to refer to many general principles or set of principles formulated to explain the events in the world or relations between such events. The theories I shall refer to are social theories, that is those theories which attempt to account for social events. Not only do such theories provide explanations for past social behaviour, but they also offer predictions as to the future. Social policies are based upon theories of social behaviour, since those who formulate the policies make certain assumptions about the policies and the social objectives they seek to achieve through political actions derived from such policies. To take a well-documented example, policy emphasises the importance of free education from kindergarten through to university level, the desired objective being not merely that education should be free to anybody who wishes to take advantage of it but, more importantly, that free education should bring about social mobility and equality of opportunity. The casual relationship between the concepts of free education and those of social mobility and equality of opportunity is based upon a theoretical assumption about the way society works.