In fact, the difficulty of the latter, tho less obvious, is equally great.

The study of principles makes demands upon thought that are open and unmistakable; its conclusions, drawn in the cold light of reason, are uncolored by feeling, and are acceptable of all men so long as the precise application that may justly be made of them is not foreseen.

But conclusions regarding practical questions of public policy, tho they may appear to be simple, usually are biased and complicated by assumptions, prejudices, selfish interests, and feelings, deep-rooted and often unsuspected.
No practical problem in the field of economics can be solved as if it were solely and purely an economic problem.

It is always in some measure also a political, moral, and social problem.

The task of the economist "as such" is the analysis of the economic valuation-aspects of these problems.