position, the position taken up by Professor Kroeber. They may say that they have never believed in the purely psychological causation of the terminology of relationship. In reply to such an attitude I can only express my conviction that the paper of Professor Kroeber is only the explicit and clear statement of an attitude which is implicit in the work of nearly all, if not all, the opponents of Morgan since McLennan. Whether they have themselves recognised it or not, I believe that it has been this underlying attitude towards sociological problems which has prevented them from seeing what is good in Morgan's work, from sifting out the chaff from the wheat of his argument, and from recognising how great is the importance to the science of sociology of the body of facts which Morgan was the first to collect and study. I feel that we owe a debt of gratitude to Professor Kroeber for having brought the matter into the open and for having presented, as a clear issue, a fundamental problem of the methods of sociology.
Lastly, I should like to point out how rigorous and exact has been the process of the determination of the nomenclature of relationship by social conditions which has been demonstrated in these lectures. We have here a case in which the principle of determinism applies with a rigour and definiteness equal to that of any of the exact sciences. According to my scheme, not only has the general character of systems of relationship been strictly determined by social conditions, but