The Marxian reply to this mainstream view is as follows. The attempt to discard the theoretical relevance of the necessary preconditions of Marx's value analysis in volume 1 of "Capital" through a reductio ad absurdum is superficial. By first identifying that the preconditions necessary for J. B. Clark's old model of "aggregate" marginal productivity to hold true are the same as those necessary for Marxian values to conform to relative prices, we are then supposed to conclude that the foundation of Marx's analysis "as based in these preconditions" is faulty "because" Clark's model had been proven wrong in the Cambridge capital controversy. The superficiality stems from the fact that those who support this reduction forget that the Cambridge capital controversy called the entire concept of marginal productivity into question by attacking not Clark's special case assumptions but the notion that physical capital can be aggregated. Marx simply does not run into this problem because his analysis does not rely on an aggregation of physical quantities that receive a return based on their contribution as "factors" of production. The fact that marginal productivity in its aggregate form is "a hypothesis regarded as disproved by all sides during the Cambridge capital controversy" has nothing to do with the validity of the special cases of Marx, and thus we "would not" "have a "pure" state of capitalist society where Marx's exploitation theory and its main supposed confutation (Clark) were "both" true", as is concluded from this view," because" the "correctness" or "incorrectness" of Clark's aggregate marginal productivity scheme in this case flows not from special case assumptions but from the fact that he is aggregating physical units of capital; i.e., Clark's argument would still not hold true "even with" the assumed special cases.