 Western economic theorists starting with the eighteenth century Scots economists Sir James Stuart and Smith differentiated pre-modern natural (or self-subsistent) economies from civilized economies marked by a division of labour that necessitated exchange.Like early sociologist Émile Durkheim, they viewed natural economies as characterized by mechanical solidarity (like so many peas in a pod) whereas the civilized division of labour made producers mutually dependent upon one another resulting in organic solidarity.These oppositions solidified by the late nineteenth century in the evolutionary idea of primitive communism marked by mechanical solidarity as the antithesis and alter ego of Western ""Homo economicus"".