This book is a somewhat revised version of the Gifford Lectures delivered at the University of Glasgow in 1974 and 1975. Lord Gifford wished the lectures given on his foundation to be ‘popular’, by which I take him to have meant ‘non-technical’. I have tried to comply with his wish, not only because he expressed it, but for two further reasons. The first is that the subject is of interest and concern to the general reader. The second is that it is no longer possible for a single individual to master all the disciplines that are required for a full academic treatment of it. He would need to be a philosopher, a theologian, a sociologist, and a historian at the very least. Yet it remains necessary to attempt something on a fairly large scale because important issues otherwise go by default. If philosophers always confine themselves to small-scale manageable problems of the sort that can be handled with full analytical rigour they are exposed, by their very concentration, to the risk of allowing fundamental assumptions to go uncriticized and even, perhaps, unnoticed. It looks as if the only practicable solution is a sketch large enough in scale to reveal these wider assumptions, but with enough detail to display the argument clearly and enable it to be checked. The whole will be too obviously incomplete to masquerade as a finished picture.
Such a compromise is beset with difficulties, and I am, therefore, more than usually aware of the many debts that I owe. First I must thank the University of Glasgow for the invitation to deliver the lectures and for the overwhelmingly generous hospitality which my wife and I received during our visits in two successive years. I am grateful to Colgate University, New York, and the University of Canterbury, New Zealand for the opportunity to give some of the lectures again, and for the stimulus provided by, in particular, Professor R. V. Smith of Colgate and Mr J. C. Thornton of Canterbury. I have received continuous help and encouragement from Mr J. R. Lucas. Those who, at various stages, have read the manuscript in whole or in part and have helped me with their comments, are too numerous for me to mention all of them. They include Professor John Howes, Professor Gene Outka, Professor C. R. Kordig, Dr R. J. Delahunty, and Dr Eleanor Dand.
In addition I owe a special debt to Professor R. M. Hare. His contributions to moral philosophy have been so influential that it would have been impossible in a study like this either to ignore them or to do them justice, let alone to match their clarity and rigour. In philosophy there is no greater compliment than dissent, and I am grateful for the stimulus and challenge of his thought over many years.