Dual Nature of Labour, a specific social property human labour acquires in commodity production. The labour that helps create a commodity is, on the one hand, 95 concrete labour and, on the other, abstract labour. This duality gives rise to the dual nature of the commodity, in that concrete labour creates its use value and abstract labour, its value. The dual nature of labour is an expression of production relations between people, of the actual contradictions inherent in commodity production. In the context of simple commodity production the contradiction between concrete and abstract labour exists as antagonism between private and social labour. This leads to differentiation of small commodity producers, to transformation of simple commodity production into capitalist production, where the antagonism between social and private labour reaches its peak. Under socialism, the core of which is social ownership of the means of production, private labour ceases to exist. Labour becomes directly social in nature. The contradiction between concrete and abstract labour is no longer antagonistic. Under these conditions, the discrepancies that may arise between concrete and abstract labour are overcome through planned management of production development by society, the socialist state. Once the transition to communism is complete, the direct social nature of labour will become fully mature, and the product of labour will no longer be a commodity, and when the commodity withers away, the dual nature of labour embodied in it will cease to exist. Marx was responsible for the scientific discovery of the dual nature of labour, which provides the methodological basis for Marxist-Leninist economic theory. The enigma of capitalist exploitation, the process of creating surplus value, could not be unravelled unless the dual nature of labour and the functional significance of both its aspects were revealed. Thus, Marx demonstrated that, by his concrete labour, the worker maintains the value of the means of production in the product of his labour and by his abstract labour, he creates a new value exceeding the value of his labour power. Under capitalism, the contradiction between social and private labour becomes the basic contradiction of capitalism which is an expression, in particular, of the irreconcilability of the interests of the bourgeoisie and its gravedigger, the proletariat.