Although the liberty to publish one’s opinions on any subject without regard to authority or the prejudices of one’s neighbours is now a well-established principle, I imagine that only the minority of those who would be ready to fight to the death rather than surrender it could defend it on rational grounds.  We are apt to take for granted that freedom of speech is a natural and inalienable birthright of man, and perhaps to think that this is a sufficient answer to all that can be said on the other side.  But it is difficult to see how such a right can be established.

If a man has any “natural rights,” the right to preserve his life and the right to reproduce his kind are certainly such.  Yet human societies impose upon their members restrictions in the exercise of both these rights.  A starving man is prohibited from taking food which belongs to somebody else.  Promiscuous reproduction is restricted by various laws or customs.  It is admitted that society is justified in restricting these elementary rights, because without such restrictions an ordered society could not exist.  If then we

[13] concede that the expression of opinion is a right of the same kind, it is impossible to contend that on this ground it can claim immunity from interference or that society acts unjustly in regulating it.  But the concession is too large.  For whereas in the other cases the limitations affect the conduct of every one, restrictions on freedom of opinion affect only the comparatively small number who have any opinions, revolutionary or unconventional, to express.  The truth is that no valid argument can be founded on the conception of natural rights, because it involves an untenable theory of the relations between society and its members.

On the other hand, those who have the responsibility of governing a society can argue that it is as incumbent on them to prohibit the circulation of pernicious opinions as to prohibit any anti-social actions.  They can argue that a man may do far more harm by propagating anti-social doctrines than by stealing his neighbour’s horse or making love to his neighbour’s wife.  They are responsible for the welfare of the State, and if they are convinced that an opinion is dangerous, by menacing the political, religious, or moral assumptions on which the society is based, it is their duty to protect society against it, as against any other danger.

[14]

The true answer to this argument for limiting freedom of thought will appear in due course.  It was far from obvious.  A long time was needed to arrive at the conclusion that coercion of opinion is a mistake, and only a part of the world is yet convinced.  That conclusion, so far as I can judge, is the most important ever reached by men.  It was the issue of a continuous struggle between authority and reason—­the subject of this volume.  The word authority requires some comment.