Origins of the Family, Private Property, and the State
The following chapters are, in a sense, the execution of a bequest. No less a man than Karl Marx had made it one of his future tasks to present the results of Morgan’s researches in the light of the conclusions of his own — within certain limits, I may say our — materialistic examination of history, and thus to make clear their full significance. For Morgan in his own way had discovered afresh in America the materialistic conception of history discovered by Marx forty years ago, and in his comparison of barbarism and civilization it had led him, in the main points, to the same conclusions as Marx. And just as the professional economists in Germany were for years as busy in plagiarizing Capital as they were persistent in attempting to kill it by silence, so Morgan's Ancient Society  received precisely the same treatment from the spokesmen of “prehistoric” science in England. My work can only provide a slight substitute for what my departed friend no longer had the time to do. But I have the critical notes which he made to his extensive extracts from Morgan, and as far as possible I reproduce them here.
According to the materialistic conception, the determining factor in history is, in the final instance, the production and reproduction of the immediate essentials of life. This, again, is of a twofold character. On the one side, the production of the means of existence, of articles of food and clothing, dwellings, and of the tools necessary for that production; on the other side, the production of human beings themselves, the propagation of the species. The social organization under which the people of a particular historical epoch and a particular country live is determined by both kinds of production: by the stage of development of labor on the one hand and of the family on the other.
The lower the development of labor and the more limited the amount of its products, and consequently, the more limited also the wealth of the society, the more the social order is found to be dominated by kinship groups. However, within this structure of society based on kinship groups the productivity of labor increasingly develops, and with it private property and exchange, differences of wealth, the possibility of utilizing the labor power of others, and hence the basis of class antagonisms: new social elements, which in the course of generations strive to adapt the old social order to the new conditions, until at last their incompatibility brings about a complete upheaval. In the collision of the newly-developed social classes, the old society founded on kinship groups is broken up; in its place appears a new society, with its control centered in the state, the subordinate units of which are no longer kinship associations, but local associations; a society in which the system of the family is completely dominated by the system of property, and in which there now freely develop those class antagonisms and class struggles that have hitherto formed the content of all written history.
It is Morgan’s great merit that he has discovered and reconstructed in its main lines this prehistoric basis of our written history, and that in the kinship groups of the North American Indians he has found the key to the most important and hitherto insoluble riddles of earliest Greek, Roman and German history. His book is not the work of a day. For nearly forty years he wrestled with his material, until he was completely master of it. But that also makes his book one of the few epoch-making works of our time.
In the following presentation, the reader will in general easily distinguish what comes from Morgan and what I have added. In the historical sections on Greece and Rome I have not confined myself to Morgan’s evidence, but have added what was available to me. The sections on the Celts and the Germans are in the main my work; Morgan had to rely here almost entirely on secondary sources, and for German conditions — apart from Tacitus — on the worthless and liberalistic falsifications of Mr. Freeman. The treatment of the economic aspects, which in Morgan’s book was sufficient for his purpose but quite inadequate for mine, has been done afresh by myself. And, finally, I am, of course, responsible for all the conclusions drawn, in so far as Morgan is not expressly cited.
 Ancient Society, or Researches in the Lines of Human Progress from Savagery, through Barbarism to Civilization, by Lewis H. Morgan, London, Macmillan & Co., 1877. The book was printed in America and is peculiarly difficult to obtain in London. The author died some years ago. [For the purposes of this edition, all references to Ancient Society are from the Charles H. Kerr edition, Chicago. — Ed.]