When previously isolated societies come into contact with the outside world they undergo certain obvious changes. Professor Wilson has long been interested in these changes, particularly as they affect the peoples of Africa as they come into ever closer contact with European society. She sees, as the most general change going on in society, a change in scale, that is in the number of people interacting and the closeness of their interaction. In small societies the few people react closely, in large-scale societies more people react with more people, but less closely. The total amount of interaction is seen as constant. The religious aspect of a changing society is not immune to change. Ritual and religion in primitive society were directed towards the well-being of the group. In larger scale societies it is the individual aspect which is more important. Religion becomes more personalised. In her final two chapters Professor Wilson considers the implications for modern industrialised society of the lessons which may be drawn from religious change in traditional African societies.