The idea of freedom of [communication] has no meaning in the abstract. To be able to shout about it, to write about it, to disagree with others about it is to have it. To have reached perfect consensus about it, to defer to authoritative proclamations about it, to have foreclosed debate on it, to fear to press grievances about it is to have lost it. Unless acted upon with sometimes outrageous zeal, it cannot have a bearing on the everyday needs of citizens. What is most important, however, and what must continue unabated, is the dialogue itself. It will proceed through cases at law, resolutions, statutes, articles, books, research proposals, polemics, yes, even in demands for revolutionary changes and, hopefully, in spirited classroom discussions.