“ Even when a man without fortune receives credit in his capacity of industrialist or merchant, it occurs with the expectation that he will function as capitalist and appropriate unpaid labour with the borrowed capital. ”
 Karl Marx, Das Kapital (1894). copy citation

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“What distinguishes interest-bearing capital — in so far as it is an essential element of the capitalist mode of production — from usurer's capital is by no means the nature or character of this capital itself. It is merely the altered conditions under which it operates, and consequently also the totally transformed character of the borrower who confronts the money-lender. Even when a man without fortune receives credit in his capacity of industrialist or merchant, it occurs with the expectation that he will function as capitalist and appropriate unpaid labour with the borrowed capital. He receives credit in his capacity of potential capitalist. The circumstance that a man without fortune but possessing energy, solidity, ability and business acumen may become a capitalist in this manner — and the commercial value of each individual is pretty accurately estimated under the capitalist mode of production — is greatly admired by apologists of the capitalist system.” source