Now it is manifest that according to this theory the moral unity to be expected in different ages is not a unity of standard, or of acts, but a unity of tendency. Men come into the world with their benevolent affections very inferior in power to their selfish ones, and the function of morals is to invert this order. The extinction of all selfish feeling is impossible for an individual, and if it were general, it would result in the dissolution of society. The question of morals must always be a question of proportion or of degree. At one time the benevolent affections embrace merely the family, soon the circle expanding includes first a class, then a nation, then a coalition of nations, then all humanity, and finally, its influence is felt in the dealings of man with the animal world. In each of these stages a standard is formed, different from that of the preceding stage, but in each case the same tendency is recognised as virtue. We have in this fact a simple, and as it appears to me a conclusive, answer to the overwhelming majority of the objections that are continually and confidently urged against the intuitive school. That some savages kill their old parents, that infanticide has been practised without compunction by even civilised nations, that the best Romans saw nothing wrong in the gladiatorial shows, that political or revengeful assassinations have been for centuries admitted, that slavery has been sometimes honoured and sometimes condemned, are unquestionable proofs that the same act may be regarded in one age as innocent, and in another as criminal. Now it is undoubtedly true that in many cases an historical examination will reveal special circumstances, explaining or palliating the apparent anomaly. It has been often shown that the gladiatorial shows were originally a form of human sacrifice adopted through religious motives; that the rude nomadic life of savages rendering impossible the preservation of aged and helpless members of the tribe, the murder of parents was regarded as an act of mercy both by the murderer and the victim; that before an effective administration of justice was organised, private vengeance was the sole preservative against crime,(115) and political assassination against usurpation; that the insensibility of some savages to the criminality of theft arises from the fact that they were accustomed to have all things in common; that the Spartan law, legalising theft, arose partly from a desire to foster military dexterity among the people, but chiefly from a desire to discourage wealth; that slavery was introduced through motives of mercy, to prevent conquerors from killing their prisoners.(116) All this is true, but there is another and a more general answer. It is not to be expected, and it is not maintained, that men in all ages should have agreed about the application of their moral principles. All that is contended for is that these principles are themselves the same. Some of