Thus we have seen that by discriminating the spheres of non-interference and interference, according to a supposed demarcation between the sphere of “self” and of “others,” a hopelessly confused classification has been introduced. Sometimes the maintenance of external conditions of good life, well within the power of the State, is forbidden on the same grounds as the direct promotion of morality, which is impossible to it. In other cases the enforcement of moral obligations is taken to lie within the functions of the State, although not only is the enforcement of moral obligations _per se_ a contradiction in terms, but almost always, as in the cases in question, the attempt to effect it is sure to frustrate itself, by destroying the springs on which moral action depends. {69} It is worth noticing, in conclusion, that in two examples, [1] the one trivial, the other that of slavery, both theoretically and practically very important, Mill recognises a principle wholly at variance with his own. Here he is aware that it may be right, according to the principle of liberty, to restrain a man, for reasons affecting himself alone, from doing what at the moment he proposes to do. For we are entitled to argue from the essential nature of freedom to what freedom really demands, as opposed to what the man momentarily seems to wish. “It is not freedom to be allowed to alienate his freedom,” as it is not freedom to be allowed to walk over a bridge which is certain to break down and cause his death. Here we have in germ the doctrine of the “real” will, and a conception analogous to that of Rousseau when he speaks of a man “being forced to be free.” [1] Pp. 57 and 61.