This personal account expresses a dissatisfaction with the social system under which we live; it arises from the author's wide experience of the relations between the developing countries and the Western world. Sir Joseph's thesis is that in taking that the West has to offer and deploying it in the Third World one can see more clearly the constraints and drawbacks of our own social and economic system. This is the challenge. The book sets out to explore the ways in which we could move away from the limitations and injustices of our system towards something better. Based on the Eddington Memorial Lectures given at the University of Cambridge in November 1974, the book sets out the belief that the Christian faith offers the incentive to undertake a revision of our social life that will call for sacrifice from those of us who are now affluent and powerful.