Engels' preface to Vol. 3 of Capital

One need not strain his thinking powers to see that this explanation for the profits 
of capital, as advanced by "vulgar economy," amounts in practice to the same thing as 
the Marxian theory of surplus-value; that the workers are in just the same 
"unfavourable condition" according to Lexis as according to Marx; that they are just 
as much the victims of swindle because every non-worker can sell commodities above 
price, while the worker cannot do so; and that it is just as easy to build up an at 
least equally plausible vulgar socialism on the basis of this theory, as that built 
in England on the foundation of Jevons.s and Menger.s theory of use-value and 
marginal utility. I even suspect that if Mr. George Bernard Shaw had been familiar 
with this theory of profit, he would have likely fallen to with both hands, 
discarding Jevons and Karl Menger, to build anew the Fabian church of the future upon 
this rock.


Michael Perelman