If one does one thing one cannot do another. If we substitute the well-worn saying "one cannot eat his cake and have it" we indicate the economic plane of constructive comparison with all needful clearness.
This is in fact the situation that has been already under discussion at such length above and the economic quality of which we are just now in quest arises from neither more nor less than the fact of our dependence in the working out of our personal problems upon limited external resources. The eventual solution sought under these circumstances remains ethical as before. But to reach it, it is necessary to bring into consideration not only such other interests and ends as the psycho-physical structure of human nature and the laws of character-development show to be involved, but a still wider range of interests less intimately or "internally" related to the focal interest of the occasion but imperatively requiring to be heard. If my acquisition of a phonograph turns upon the direct psychological bearing of the new interest upon my other interests, its probable effects whether good or bad upon my musical tastes and the diplomatic complications with my neighbors in which the possession of the instrument may involve me, the problem of its purchase remains clearly in the ethical phase. But when I count the cost in terms of sacrifices which the purchase price makes necessary, from literature down to food and fuel, and must draw this whole range of fact also into the adjustment if I can, the economic phase is reached. In principle two entire and very concrete schemes of life now stand opposed. Just _what_ concrete sacrifices I shall make I do not know--this, in fact, is one way of stating my problem. Nor, conversely, do I know just what I shall be able to make the phonograph worth to me. It is my task to come to a conclusion in the case that shall be explicit and clear enough to enable me to judge in _the event_ whether my expectation has been realized and I have acted wisely or unwisely. Thus a problem is economic when the fact of the limitation of my external resources must be eventually and frankly faced. The characteristic quality of a problem grown economic is a certain vexatiousness and seeming irrationality in the ill-assorted array of nevertheless indisputable interests, prosaic and ideal, that have to be reduced to order.