The Key to Historical Development (Engels)

“According to the materialistic conception, the decisive element of history is pre-eminently the production and reproduction of life and its material requirements.   This implies, on the one hand, the production of the means of existence (food, clothing, shelter and the necessary tools); on the other hand, the generation of children, the propagation of the species. The social institutions, under which the people of a certain historical period and of a certain country are living, are dependent on these two forms of production; partly on the development of labour, partly on that of the family. The less labour is developed, and the less abundant the quantity of its production and, therefore, tho wealth of society, the more society is seen to be under the domination of sexual ties. However, under this formation based on sexual ties, the productivity of labour is developed more and more. At the same time, private property and exchange, distinctions of wealth, exploitation of the labour power of others and, by this agency, the foundation of class antagonism, are formed. These new elements of society strive in the course of time to adapt the old state of society to the new conditions, until the impossibility of harmonising these two at last leads to a complete revolution. The old form of society founded on sexual relations is abolished in the clash with the recently developed social classes. A new society steps into being, crystallised into the state. The units or the latter are no longer sexual, but local groups; a society in which family relations are entirely subordinated to property relations, thereby freely developing those class antagonisms and class struggles that make up the contents of all written history up to the present time.”