Utopia and Nirvana are by definition their own sufficient reason, and it may be that to contemplate them is well worth the abandonment of feeble attempts to control the action of events. Renunciation, however, is a luxury in which all men cannot indulge. They will somehow seek to control the behavior of others, if not by positive law then at least by persuasion. When men are in that posture toward events they are a public, as I am here defining the term; their opinions as to how others ought to behave are public opinions. The more clearly it is understood what the public can do and what it cannot, the more effectively it will do what lies within its power to do well and the less it will interfere with the liberties of men. The rôle of public opinion is determined by the fact that its relation to a problem is external. The opinion affects an opinion, but does not itself control the executive act. A public opinion is expressed by a vote, a demonstration of praise or blame, a following or a boycotting. But these manifestations are in themselves nothing. They count only if they influence the course of affairs. They influence it, however, only if they influence an actor in the affair. And it is, I believe, precisely in this secondary, indirect relationship between public opinion and public affairs that we have the clue to the limits and the possibilities of public opinion. 2 It may be objected at once that an election which turns one set of men out of office and installs another is an expression of public opinion which is neither secondary nor indirect. But what in fact is an election? We call it an expression of the popular will. But is it? We go into a polling booth and mark a cross on a piece of paper for one of two, or perhaps three or four names. Have we expressed our thoughts on the public policy of the United States? Presumably we have a number of thoughts on this and that with many buts and ifs and ors. Surely the cross on a piece of paper does not express them. It would take us hours to express our thoughts, and calling a vote the expression of our mind is an empty fiction. A vote is a promise of support. It is a way of saying: I am lined up with these men, on this side. I enlist with them. I will follow. I will buy. I will boycott. I will strike. I applaud. I jeer. The force I can exert is placed here, not there. The public does not select the candidate, write the platform, outline the policy any more than it builds the automobile or acts the play. It aligns itself for or against somebody who has offered himself, has made a promise, has produced a play, is selling an automobile. The action of a group as a group is the mobilization of the force it possesses.