translation of classificatory terms or classificatory terms as the equivalents of our own. The difficulty or impossibility of conforming to complete truth and reality, when we attempt this task, is the best witness to the fundamental difference between the two modes of denoting relationship.

I do not know of any discovery in the whole range of science which can be more certainly put to the credit of one man than that of the classificatory system of relationship by Lewis Morgan. By this I mean, not merely that he was the first to point out clearly the existence of this mode of denoting relationship, but that it was he who collected the vast mass of material by which the essential characters of the system were demonstrated, and it was he who was the first to recognise the great theoretical importance of his new discovery. It is the denial of this importance by his contemporaries and successors which furnishes the best proof of the credit which is due to him for the discovery. The very extent of the material he collected[1] has probably done much to obstruct the recognition of the importance of his work. It is a somewhat discouraging thought that, if Morgan had been less industrious and had amassed a smaller collection of material which could have been embodied in a more available form, the value of his work would probably have been far more widely recognised than it is to-day. The volume of his material is, however, only a subsidiary factor in the process which has led to the neglect or rejection of the importance of Morgan’s discovery. The chief cause of the neglect is one for which Morgan must himself largely bear the blame. He was not content to demonstrate, as he might to some extent have done from his own material, the close connection between the terminology of the classificatory system of relationship and forms of social organisation. There can be little 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.

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.

This aspect of the problem, which has been neglected or put on one side by the followers of McLennan, was not so treated by McLennan himself. As we should expect from the general character of his work, McLennan clearly recognised that the classificatory system must have been determined by social conditions, and he tried to show how it might have arisen as the result of the change from the Nair to the Tibetan form of polyandry.[3] He even went so far as to formulate varieties of this process by means of which there might have been produced the chief varieties of the classificatory system, the existence of which had been demonstrated by Morgan. It is quite clear that McLennan had no doubts about the necessity of tracing back the social institution of the classificatory system of relationship to social causes, a necessity which has been ignored or even explicitly denied by those who have followed him in rejecting the views of Morgan. It is one of the many unfortunate consequences of McLennan’s belief in the importance of polyandry in the history of human society that it has helped to prevent his followers from seeing the social importance of the classificatory system. They have failed to see that the classificatory system may be the result neither of promiscuity nor of polyandry, and yet have been determined, both in its general character and in its details, by forms of social organisation.

Since the time of Morgan and McLennan few have attempted to deal with the question in any comprehensive manner. The problem has inevitably been involved in the controversy which has raged between the advocates of the original promiscuity or the primitive monogamy of mankind, but most of the former have been ready to accept Morgan’s views blindly, while the latter have been content to try to explain away the importance of conclusions derived from the classificatory system without attempting any real study of the evidence. On the side of Morgan there has been one exception in the person of Professor J. Kohler,[4] who has recognised the lines on which the problem must be studied, while on the other side there has been, so far as I am aware, only one writer who has recognised that the evidence from the nature of the classificatory system of relationship cannot be ignored or belittled, but must be faced and some explanation alternative to that of Morgan provided.

This attempt was made four years ago by Professor Kroeber,[5] of the University of California. The line he takes is absolutely to reject the view common to both Morgan and McLennan that the nature of the classificatory system has been determined by social conditions. He explicitly rejects the view that the mode of using terms of relationship depends on social causes, and puts forward as the alternative that they are conditioned by causes purely linguistic and psychological.

It is not quite easy to