publishing different from those of transportation, those of
agriculture different from those of mining; or, in the field of
commerce, the purposes of the retailer are different from those of the
wholesale merchant. There can be no limit to such subdivisions; each
particular industry has its own aims, and in the same industry a large
variety of tasks are united. We should accordingly be led to an ample
classification of special economic ends with pigeonholes for every
possible kind of business and of labor. The psychologist would have to
find for every one of these ends the right mental means. This would be
the ideal system of economic psychology.

But we are still endlessly far from such a perfect system. Modern
educational psychology and medical psychology have reached a stage at
which an effort for such a complete system might be realized, but
economic psychology is still at too early a stage of development. It
would be entirely artificial to-day to aim at such ideal completeness.
If we were to construct such a complete system of questions, we should
have no answers. In the present stage nothing can be seriously
proposed but the selection of a few central purposes which occur in
every department of business life, and a study of the means to reach
these special ends by the discussion of some typical cases which may
clearly illustrate the methods involved.

From this point of view we select three chief purposes of business
life, purposes which are important in commerce and industry and every
economic endeavor. We ask how we can find the men whose mental
qualities make them best fitted for the work which they have to do;
secondly, under what psychological conditions we can secure the
greatest and most satisfactory output of work from every man; and
finally, how we can produce most completely the influences on human