I first came to Queen's University Belfast to lecture in social philosophy in January 1976, a time when tit-for-tat atrocities were usual. My predecessor, the late Alan Milne, had just moved to a Chair of Politics at the University of Durham, and I took over his fully worked-out courses in moral and political philosophy and in philosophy of law. He became a friend and mentor, and I took great pleasure in learning from him throughout his life. Yet I learnt, too, from his students. Philosophical studies at Queen's were polarized at that time in a way that matched community differences, but students from across that divided society had come to Alan Milne to be taught these controversial subjects. Political and legal philosophies mattered. Rights, in their various manifestations, were an important political issue. I was forced to reflect hard. I acknowledge here the great debt I owe to Alan Milne and to the succeeding generations of students who joined me in following where he had led. The reflections of the years ground the present book.

A more immediate cause of the book's writing was the encouragement received from sympathetic publisher Steven Gerrard and series editor John Shand. I am grateful, too, to the anonymous referees from North America and the UK. Theirs was not a thankless task, since I thank them all; but that is a poor return for their help. Many others have helped me, also, in sharing and shaping my thoughts about rights in many different ways.