Historical materialism is a methodological approach to the study of human societies and their development over time first articulated by Karl Marx (1818–1883) as the materialist conception of history. It is principally a theory of history according to which the material conditions of a society's mode of production (its way of producing and reproducing the means of human existence—in Marxist terms, the union of its productive capacity and social relations of production) fundamentally determine its organisation and development.