And the more capitalist production develops, the greater will be the degree of approximation in particular cases, for the progress of Capitalism signifies a continuous increase of constant capital, a more mechanical character being given to industrial processes, and a reduction of variable capital to the necessary minimum, so that the differences in the organic composition of capitalist undertakings become less, thus bringing the average rate of profit and the rate of surplus value nearer to each other. This indirect and difficult method of realising profits involves the fact that the capitalist does not distinctly observe the exploitation of wage labour practised by him, but he believes that the profit is owing to his own commercial ability. This difficult section of the outlines of the economic doctrines of Marx can be most fitly concluded by quoting the comprehensive observations of Marx himself upon this subject, which he gives at the end of his book.--("Capital" (German), Vol. III., 2, pp. 355-6.) "In a capitalist society, this surplus value or this surplus product (leaving aside accidental fluctuations in its distribution and considering only the regulating law of these fluctuations) is divided among the capitalists as a dividend in proportion to the percentage of the total social capital held by each. In this shape the surplus value appears as the average profit, which in its turn is separated into profits of enterprise and interest, and which in this way may fall into the hands of different kinds of capitalists. Just as the active capitalist squeezes surplus labour, and with it surplus value in the form of profit out of the worker, so the landlord in his turn squeezes a portion of this surplus value from the capitalist in the shape of rent. Hence when speaking of profit as that portion of surplus value which falls to the share of capital, we mean average profit.... Profits of capital (profits of enterprise plus interest) and ground rent are merely particular constituents of surplus value.... If added together, these parts form the sum of the social surplus value. A large part of profits is immediately transformed into capital." In this way, capital grows, or, as Marx says, accumulates. 7. _Surplus Value as Social Driving Force._ It has been said already that capital is that portion of wealth which is devoted to the object of increasing wealth, of gain, the extraction of profit or surplus value. This object dominates the capitalist class; the desire for surplus value is the leading impulse and principle motive of their activity. Goaded by this desire and exclusively occupied with their special interests, this class unconsciously and unintentionally develops the entire capitalist system and leads it to ever higher and more comprehensive stages.