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.
