restraint, is an evil: but the restraints in question affect only that part of conduct which society is competent to restrain, and are wrong solely because they do not really produce the results which it is desired to produce by them. As the principle of individual liberty is not involved in the doctrine of Free Trade, so neither is it in most of the questions which arise respecting the limits of that doctrine: as for example, what amount of public control is admissible for the prevention of fraud by adulteration; how far sanitary precautions, or arrangements to protect work-people employed in dangerous occupations, should be enforced on employers. Such questions involve considerations of liberty, only in so far as leaving people to themselves is always better, caeteris paribus