The idea that the profits of capital are really the rewards of a just society for the foresight and thrift of those who sacrificed the immediate pleasures of spending in order that society might have productive capital, had a certain validity in the early days of capitalism, when productive enterprise was frequently initiated through capital saved out of modest incomes. The idea, as a moral justification of present inequalities of privilege, has become more and more dishonest, since the increased centralization of power and privilege makes it possible for those who make the largest investments in industry to do so without any diminution of even the most luxurious living standards. Since we are living in a world in which there is too much capital for production and too little for consumption, the argument that economic inequality is necessary for the accumulation of capital resources has lost even its economic validity. Yet it is still used by privileged classes to establish a specious connection between virtue or social function and privilege.
Reinhold Niebuhr, Moral Man and Immoral Society, 1932