The building of houses. With savages each family has as a matter of course its own cave or hut like the separate family tent of the nomads. This separate domestic economy is made only the more necessary by the further development of private property. With the agricultural peoples a communal domestic economy is just as impossible as a communal cultivation of the soil. A great advance was the building of towns. In all previous periods, however, the abolition of individual economy, which is inseparable from the abolition of private property, was impossible for the simple reason that the material conditions governing it were not present. The setting-up of a communal domestic economy presupposes the development of machinery, of the use of natural forces and of many other productive forces – e.g. of water-supplies, of gas-lighting, steam-heating, etc., the removal [of the antagonism] of town and country. Without these conditions a communal economy would not in itself form a new productive force; lacking any material basis and resting on a purely theoretical foundation, it would be a mere freak and would end in nothing more than a monastic economy – What was possible can be seen in the towns brought about by condensation and the erection of communal buildings for various definite purposes (prisons, barracks, etc.). That the abolition of individual economy is inseparable from the abolition of the family is self-evident.