doubt that he recognised this connection, but he was not content to demonstrate the dependence of the terminology of relationship upon social forms the existence of which was already known, or which were capable of demonstration with the material at his disposal. He passed over all these early stages of the argument, and proceeded directly to refer the origin of the terminology to forms of social organisation which were not known to exist anywhere on the earth and of which there was no direct evidence in the past. When, further, the social condition which Morgan was led to formulate was one of general promiscuity developing into group-marriage, conditions bitterly repugnant to the sentiments of most civilised persons, it is not surprising that he aroused a mass of heated opposition which led, not merely to widespread rejection of his views, but also to the neglect of lessons to be learnt from his new discovery which must have received general recognition long before this, if they had not been obscured by other issues. [1] _Systems of Consanguinity and Affinity of the Human Family: Smithsonian Contributions to Knowledge_, vol. xvii.; Washington, 1871. The first to take up the cudgels in opposition to Morgan was our own pioneer in the study of the early forms of human society, John Ferguson McLennan.[2] He criticised the views of Morgan severely and often justly, and then pointing out, as was then believed to be the case, that no duties or rights were connected with the relationships of the classificatory system, he concluded that the terms formed merely a code of courtesies and ceremonial addresses for social intercourse. Those who have followed him have usually been content to repeat the conclusion that the classificatory system is nothing more than a body of mutual salutations and terms of address. They have failed to see that it still remains necessary to explain how the terms of the classificatory system came to be used in mutual salutation. They have failed to recognise that they were either rejecting the principle of determinism in sociology, or were only putting back to a conveniently remote distance the consideration of the problem how and why the classificatory terms came to be used in the way now customary among so many peoples of the earth. [2] _Studies in Ancient History_, 1st series, 1876, p. 331.