Since the foregoing was written, I have found that another theorist, Professor Alvin S. Johnson, had also given consideration to the same idea, as a means of escape from the Austrian circle. Professor Johnson refers to the notion briefly in his review of _Social Value_ (_Am. Econ. Rev._, June, 1912, p. 322), holding that the doctrine is logically tenable, though rejecting it on psychological grounds. "The value of a thing newly created can be explained only with reference to values antecedently existing." That there is a continuity in the value system, as in the whole social-mental life of men, I should be the last to deny. But it is not the antecedently existing values, _as_ antecedently existing, that give value to the new piece of wealth. The antecedent values function only as _persisting_, as _contemporary_ social forces. We do not find the motivating power of existing values in the ashes of burnt out desire! It seems to me very essential to distinguish the two methods of approach to the problem. It is possible to state a historical sequence--if you know it,--showing how values have historically come and gone. But for an equilibrium picture, of the sort that our price theory demands, where there is a mechanical balancing of contemporary factors (as in Marshall's balls in the bowl illustration), such an account is of no use. Existing social forces have their history. But, at a given moment, they are what they are, and what they _were_ at a different time adds no ounce of weight to the power they now exert. If a quantitative account of value is called for--and price-theory is essentially concerned with the measurement of values--we must bring measure and measured into contemporary balance. The historical account is one thing; the cross-section analysis is another. "Static theory" is a mechanical abstraction from the organic cross-section picture, which, by making it superficial, is able to make it exact.