Karl Marx made a contribution of lasting service to the theory of eco-

nomics when he drew attention to the problem of the reproduction of

the entire social capital. It is significant that in the history of economics

we find only two attempts at an exact exposition of this problem: one

by Quesney, the father of the Physiocrats, at its very inception; and in

its final stage this attempt by Marx. In the interim, the problem was

ever with bourgeois economics. Yet bourgeois economists have never

been fully aware of this problem in its pure aspects, detached from

related and intersecting minor problems; they have never been able to

formulate it precisely, let alone solve it. Seeing that the problem is of

paramount importance, their attempts may all the same help us to

some understanding of the trend of scientific economics.