The most important of these is the instinct of conventionality, which exists in all gregarious animals and often leads them to put to death any markedly peculiar member of the herd.
The next most important is the feeling of insecurity aroused by doubt as to the beliefs by which we are in the habit of regulating our lives. Whoever has tried to explain the philosophy of Berkeley to a plain man will have seen in its unadulterated form the anger aroused by this feeling. What the plain man derives from Berkeley's philosophy at a first hearing is an uncomfortable suspicion that nothing is solid, so that it is rash to sit on a chair or to expect the floor to sustain us. Because this suspicion is uncomfortable, it is irritating, except to those who regard the whole argument as merely nonsense. And in a more or less analogous way any questioning of what has been taken for granted destroys the feeling of standing on solid ground, and produces a condition of bewildered fear.
A third reason which makes men dislike novel opinions is that vested interests are bound up with old beliefs. The long fight of the church against science, from Giordano Bruno to Darwin, is attributable to this motive among others. The horror of socialism which existed in the remote past was entirely attributable to this cause. But it would be a mistake to assume, as is done by those who seek economic motives everywhere, that vested interests are the principal source of anger against novelties in thought. If this were the case, intellectual progress would be much more rapid than it is.
The instinct of conventionality, horror of uncertainty, and vested interests, all militate against the acceptance of a new idea. And it is even harder to think of a new idea than to get it accepted; most people might spend a lifetime in reflection without ever making a genuinely original discovery.
In view of all these obstacles, it is not likely that any society at any time will suffer from a plethora of heretical opinions. Least of all is this likely in a modern civilized society, where the conditions of life are in constant rapid change, and demand, for successful adaptation, an equally rapid change in intellectual outlook. There should be an attempt, therefore, to encourage, rather than discourage, the expression of new beliefs and the dissemination of knowledge tending to support them. But the very opposite is, in fact, the case. From childhood upward, everything is done to make the minds of men and women conventional and sterile. And if, by misadventure, some spark of imagination remains, its unfortunate possessor is considered unsound and dangerous, worthy only of contempt in time of peace and of prison or a traitor's death in time of war. Yet such men are known to have been in the past the chief benefactors of mankind, and are the very men who receive most honor as soon as they are safely dead.
The whole realm of thought and opinion is utterly unsuited to public control; it ought to be as free, and as spontaneous as is possible to those who know what others have believed. The state is justified in insisting that children shall be educated, but it is not justified in forcing their education to proceed on a uniform plan and to be directed to the production of a dead level of glib uniformity. Education, and the life of the mind generally, is a matter in which individual initiative is the chief thing needed; the function of the state should begin and end with insistence on some kind of education, and, if possible, a kind which promotes mental individualism, not a kind which happens to conform to the prejudices of government officials.
III
Questions of practical morals raise more difficult problems than questions of mere opinion. The thugs honestly believe it their duty to commit murders, but the government does not acquiesce. The conscientious objectors honestly hold the opposite opinion, and again the government does not acquiesce. Killing is a state prerogative; it is equally criminal to do it unbidden and not to do it when bidden. The same applies to theft, unless it is on a large scale or by one who is already rich. Thugs and thieves are men who use force in their dealings with their neighbors, and we may lay it down broadly that the private use of force should be prohibited except in rare cases, however conscientious may be its motive. But this principle will not justify compelling men to use force at the bidding of the state, when they do not believe it justified by the occasion. The punishment of conscientious objectors seems clearly a violation of individual liberty within its legitimate sphere.
It is generally assumed without question that the state has a right to punish certain kinds of sexual irregularity. No one doubts that the Mormons sincerely believed polygamy to be a desirable practice, yet the United States required them to abandon its legal recognition, and probably any other Christian country would have done likewise. Nevertheless, I do not think this prohibition was wise. Polygamy is legally permitted in many parts of the world, but is not much practised except by chiefs and potentates. If, as Europeans generally believe, it is an undesirable custom, it is probable that the Mormons would have soon abandoned it, except perhaps for a few men of exceptional position. If, on the other hand, it had proved a successful experiment, the world would have acquired a piece of knowledge which it is now unable to possess. I think in all such cases the law should only intervene when there is some injury inflicted without the consent of the injured person.
It is obvious that men and women would not tolerate having their wives or husbands selected by the state, whatever eugenists might have to say in favor of such a plan. In this it seems clear that ordinary public opinion is in the right, not because people choose wisely, but because any choice of their own is better than a forced marriage. What applies to marriage ought also to apply to the choice of a trade or profession; although some men have no marked preferences, most men greatly prefer some occupations to others, and are far more likely to be useful citizens if they follow their preferences than if they are thwarted by a public authority.