process of valuation according to the specific units involved provides the solution for the famous “value paradox” which puzzled writers for centuries. The question was: How can men value bread less than platinum, when “bread” is obviously more useful than “platinum”? The answer is that acting man does not evaluate the goods open to him by abstract classes, but in terms of the specific units available. He does not wonder whether “bread-in-general” is more or less valuable to him than “platinum-in-general,” but whether, given the present available stock of bread and platinum,