for the prevention of harm to others. This is the minimum claim the State can make, and it will be admitted that it is not only the right but the duty of the State to prevent harm to its members. That is what it is for. Now no abstract or independent principle is discoverable, why liberty of speech should be a privileged form of liberty of action, or why society should lay down its arms of defence and fold its hands, when it is persuaded that harm is threatened to it through the speech of any of its members. The Government has to judge of the danger, and its judgment may be wrong; but if it is convinced that harm is being done, is it not its plain duty to interfere?
This argument supplies an apology for the suppression of free opinion by Governments in ancient and modern times. It can be urged for the Inquisition, for Censorship of the Press, for Blasphemy laws, for all coercive measures of the kind, that, if excessive or ill-judged, they were intended to protect society against what their authors sincerely believed to be grave injury, and were simple acts of duty. (This apology, of course, does not extend to acts done for the sake of the alleged good of the victims themselves, namely, to secure their future salvation.)
Nowadays we condemn all such measures
