While historical materialism has been referred to as a materialist theory of history, Marx does not claim to have produced a master-key to history and that the materialist conception of history is not "an historico-philosophic theory of the "marche generale", imposed by fate upon every people, whatever the historic circumstances in which it finds itself". In a letter to editor of the Russian newspaper paper "Otetchestvennye Zapiskym" (1877), he explains that his ideas are based upon a concrete study of the actual conditions in Europe.