Sec. 10. But constructive interests, whether provoked by suggestion or of the more freely imaginative type, may, as has been said, be held to lie outside the scope of economic theory. How a desire for a certain thing has come to get expression may seem quite immaterial--economically speaking. Economics has no concern with human folly as such or human imitativeness, or human aspiration high or low or any other of the multitude of motives that have to do with secular changes in the "standard of living" and in the ideals of life at large. It has no concern with anything that lies behind the fact that I am in the market with my mind made up to buy or sell a thing at a certain price. And the answer to this contention must be that it first reverses and then distorts the true perspective of our economic experience. Let it be admitted freely--indeed, let it be insisted on--that the definition of a science must be determined by the pragmatic test. If an economist elects to concern himself with the problems of what has been called the "loose mechanics of trade" there can be no question of his right to do so or of the importance of the services he may render thereby, both to theory and to practice. But on the other hand economic theory cannot be therefore, once and for all, made a matter of accounting--to the effacement of all problems and aspects of problems of which the accountant has no professional cognizance. Just this, apparently, is what it means to level down all types of interest to the hedonistic, leaving aside as "extra-economic" those that too palpably resist the operation. It is acknowledged that freshly suggested modes of consumption and ends of effort require expenditure and sacrifice no less than the habitual, that the exploration of Tibet or of the Polar Seas affects the market for supplies not less certainly than the scheduled voyages of oceanic liners. Moreover, behind these scheduled voyages there are all the varied motives that induce people to travel and the desires that lead to the shipment of goods. Shall it be said that all of these motives and desires must be traceable back to settled habits of behavior and consumption? And if this cannot be maintained is it not hazardous to assume that such general problems of economic theory as the determination of market values or of the shares in distribution require no recognition of the other empirical types of interest? These types, if they are genuine, are surely important; they may well prove to be, in many ways, fundamentally important. For a commodity that has become habitual must once have been new and untried.