Rudolf Hilferding has proved the untenability of economic Marxism, and confidently announces that "the beginning of the end of the labor theory of value" has been inaugurated by the publication of the third volume of Capital. Since his criticism deals with principles, since he does not attack isolated and arbitrarily selected points or conclusions, but questions and reflects as untenable the very foundation of the Marxist system, possibility is afforded for a fruitful discussion. But since the Marxist system has to be dealt with in its entirety, this discussion must be more detailed than that which is requisite to meet the objections of the eclectics, objections based upon misunderstanding and concerned only with individual details.