The problem of how exploitation should be conceptualised in social theory is of equivalent importance to that of how we should seek to analyse domination and power. Easily the most influential theory of exploitation in sociology is that of Marx, and this has to form the initial point of reference for any appraisal of the notion. In Marx, the question of exploitation (exploitieren, ausbeuten) is inevitably bound up with his over-all characterisation of the nature and development of class systems. In tribal societies, according to Marx, production and distribution are communal. In such societies the productive forces are relatively undeveloped; there is little or no surplus production. Classes only come into being with the expansion of the productive forces, such that a surplus is generated, appropriated by an emergent dominant class of non-producers. Class relations are hence inherently exploitative, since the ruling class lives off the surplus production of the subordinate class or classes. There is a major difference, according to Marx, between the exploitative relation involved between the two main capitalist classes and the class relations found in the prior types of class society, the Ancient world and feudalism. In the latter two types of society exploitation takes the form of the appropriation of the surplus labour by the dominant class.