Censorship and all it implies in terms both of our historical understanding and of issues of enormous moment in contemporary life defies brief definition because it is an idea that always engages our prejudices, penetrates to the dim regions where our manners and mores take form, and shapes our attitude to the rule law. At the same time the responses it evokes, whether pernicious or benevolent, depend upon the actualities of the historical moment. Censorship is fascinating because its theory demands some decision on its practice whenever there is an intellectual or political...