Capital, self-expanding value, or value which begets surplus value as a result of the exploitation of wage labour. It expresses the socio-production relations between the main classes of bourgeois society—the capitalists and the wage workers. Karl Marx gave an in-depth analysis of this category of the political economy of capitalism. He refuted bourgeois economists’ interpretation of capital as an aggregate of things (means of production), and was the first to discover that "capital is not a thing, but rather a definite social production relation, belonging to a definite historical formation of society, which is manifested in a thing and lends this thing a specific social character" (Karl Marx, Capital, Vol. Ill, p. 814). Commodity production, and developed commodity circulation served as the historical conditions for the emergence of capital. The initial and overriding form of capital is its monetary form, and the general formula of capital is M-C-M’, where M is money, C, a commodity, and M’ is a sum of money plus a certain increment. Money becomes capital only when its accumulation makes it possible to purchase the means of production and labour power, and to concentrate them in the hands of one stratum of society, whereas other members of society, being personally emancipated but deprived of the means of production, become sellers of their labour power. The transformation of money into capital was accelerated by the primitive accumulation of capital. The capitalist buys the means of production, i. e., constant capital, and labour power, i. e., variable capital, and joins them in the production process. New value is created through workers’ abstract labour. The greater quantity of the newly created value compared to the value of the labour power forms surplus value, which is appropriated by the capitalist Thus, variable capital creates surplus value. The subdivision of capital into constant and variable reveals its exploitative nature. It demonstrates that the unpaidfor surplus labour of workers (see Surplus Labour), embodied in surplus value, is the source of the growth of capital. The surplus value is spent on the capitalist’s private consumption and for increasing his capital (see Accumulation of Capital) and, correspondingly, for stepping up and intensifying exploitation. The self- expansion of capital takes place during the circuit of capital and the turnover of capital. "Capital ... is a movement, a circuit-describing process going through various stages, which itself comprises three different forms of the circuit-describing process. Therefore it can be understood only as motion, not as a thing at rest" (Karl Marx, Capital, Vol. II, p. 108). Marx discovered the various methods of transferring value to the created product and described the division of capital into fixed capital and current capital. The capital functioning in the production process is productive capital. During its turnover, other parts of capital assume either the form of a commodity or of money (see Commodity Capital; Money Capital). The alienation of these parts of capital results in the formation of merchant’s capital and loan capital which bring their owners part of the surplus value created during the production process in the form of commercial profit and interest With the development of capitalism, one can observe a growing desire on the part of capitalists to extract surplus value, to accumulate capital and step up the exploitation of workers. During the imperialist stage a fierce struggle develops to obtain monopoly superprofit. Lenin further developed Marx’s theory of capital. In his works he gave a profound analysis of its movement in the epoch of imperialism and discovered a new category, finance capital.