It is striking how quickly the idea of human rights – only lately added to our moral vocabulary – has been accepted by the public as useful, indeed perhaps as indispensable for talking about the world that we live in. Throughout the West, and to some extent through the whole international community, people understand roughly what is meant by violation of human rights. And they use that phrase at times to say things that they find very important. It is the sense of our times that, whatever doubts there may be about minor moral questions and whatever respect each culture may owe to its neighbours, there are some things that should not be done to anybody anywhere. Against these things (people feel) every bystander can and ought to protest.

It is no wonder that academics are startled by this quick acceptance of the concept. They rightly point out uncertainties both about the central meaning of the term and about its borderlines. Yet in general the public is surely in the right to make use of the idea. This new conceptual tool is a powerful one and its power, like that of all such tools, is in some ways mysterious. Its full meaning is not easily explicated. It expresses rather more than we can yet put into our dictionaries. Those whose business it is to seek precision in these vast and ill-explored areas are therefore quite right to busy themselves in trying to work out its full implications and to point out the confusions which it may involve – as is done in this book. That critique is necessary because new moral insights always have to be checked for hitches and flaws. Without such checking they remain fanciful and cannot be realistically applied.