and disallow the right of the State to interfere with the free expression of opinion. So deeply is the doctrine of liberty seated in our minds that we find it difficult to make allowances for the coercive practices of our misguided ancestors. How is this doctrine justified? It rests on no abstract basis, on no principle independent of society itself, but entirely on considerations of utility.
We saw how Socrates indicated the social value of freedom of discussion. We saw how Milton observed that such freedom was necessary for the advance of knowledge. But in the period during which the cause of toleration was fought for and practically won, the argument more generally used was the injustice of punishing a man for opinions which he honestly held and could not help holding, since conviction is not a matter of will; in other words, the argument that error is not a crime and that it is therefore unjust to punish it. This argument, however, does not prove the case for freedom of discussion. The advocate of coercion may reply: We admit that it is unjust to punish a man for private erroneous beliefs; but it is not unjust to forbid the propagation of such beliefs if we are convinced that they are harmful; it is not unjust to punish him, not for holding them, but for publishing them. The truth
