The Origin of the Family, Private Property and the State

property and exchange, differences in wealth, the ability to utilize the labor power of others, and thereby the foundation of class antagonisms: new social elements that, over the course of generations, struggle to adapt the old social constitution to the new conditions, until finally the incompatibility of both brings about a complete revolution. The old society, based on kinship groups, is shattered in the collision of the newly developed social classes; in its place comes a new society, organized in the state, the subordinate units of which are no longer kinship groups but territorial groups. It is a society in which the family system is completely dominated by the property system, and in which those class antagonisms and class struggles now unfold freely—the content of all written history to date.

It is to the great credit of Morgan to have discovered and reconstructed this prehistoric foundation of our written history in its main features, and to have found in the kinship groups of the North American Indians the key that unlocks for us the most important, previously insoluble riddles of the oldest Greek, Roman, and German history. However, his work is not a one-day labor. He wrestled with his material for nearly forty years until he had completely mastered it.