History of economic thought died, Engels completed the second volume of "Das Kapital" from his notes. Marx wrote his magnum opus "Das Kapital" (1867) at the British Museum's library in London. Karl Marx begins with the concept of commodities. Before capitalism, says Marx, production was based on slavery – in ancient Rome for example – then serfdom in the feudal societies of medieval Europe. The current mode of labor exchange has produced an erratic and unstable situation allowing the conditions for revolution. People buy and sell their labor as people buy and sell goods and services. People themselves have become disposable commodities. As Marx
Influences on Karl Marx animals and tools. In a book review of the first volume of "Das Kapital", Engels wrote that Marx was "simply striving to establish the same gradual process of transformation demonstrated by Darwin in natural history as a law in the social field". In this line of thought, several authors such as William F. O'Neill, have seen that "Marx describes history as a social Darwinist 'survival of the fittest' dominated by the conflict between different social classes" and moving to a future in which social conflict will ultimately disappear in a 'classless society'" while some Marxists try to dissociate Marx from