"Adam Smith baulked at the logical conclsuion of his resolution of commodity value, and thus of the value of the annual social product, into wages and surplus-value, i.e. simply into revenue: the conclusion that the total annual product could then be entirely consume. It is never the original thinkers who draw the absurd conclusions. They rather leave this for the Says and the MacCullochs."
- Capital, Vol. 2, (pg. 466 in the Penguin edition)
That observation by Marx is also interesting considering what Keynes said about the intellectual history of Say's Law. He came down hard on Say and even Mill, but then said that those who followed them - particularly Marshall, Pigou, and Edgeworth - were too smart to put it as crudely as Say did. Still, their conclusions rely on Say's Law (whatever the hell that is - I'm not trying to minimize the arguments over the "law" itself - I'm just not interested in getting into that argument).