Abstract Labour, the social labour of those who produce commodities; labour in general, regarded independently of its concrete form. In contrast to concrete labour, abstract labour has no qualitative distinctions. No matter what purposeful form it assumes, it is productive expenditure of human labour power in the physiological sense (the use of the energy of muscles, nerves, brain, etc.). Abstract labour is not, however, a biological but a social concept. It creates the value of the commodity and is a historical category that is a feature of commodity production alone. In a subsistence economy, the social character of labour is directly manifested in concrete labour, which is a component part of the aggregate labour of the workers employed 7 in a given husbandry. Under the conditions of commodity production, the social character of labour is revealed only during the exchange of commodities. To equate commodities on the basis of value means to equate the labour that went into their production: expenditure of concrete labour is reduced to expenditure of depersonalised, homogeneous and commensurable labour. Abstract labour expresses, therefore, certain relations of production, i. e., relations between producers of commodities. It is universal human labour, the social character of which is revealed in the process of commodity exchange. Under capitalism, the social character of private labour is conveyed through abstract labour. Under socialism, private labour does not exist. All labour is directly social, and concrete and abstract labour are its two aspects. Abstract labour conveys that which is common to the various concrete kinds of directly social labour and to its social varieties (physical and mental labour, labour in town and countryside). Equation of commodities during exchange means that the various kinds of labour that went into their production are certain quantities of social labour. The labour of each member of society, being part of the aggregate directly social labour, is taken into account and controlled by society through the process of exchange. The need to reduce the expenditure of labour to abstract labour remains throughout the stage of developed socialism. It disappears only once society has built complete communism, under which the essential distinctions between different kinds of labour will be abolished, and labour will become the first vital need of all people.