152 
pI 
INTERNATIONAL TRADE 
harmonious and self-adjusting scheme? In the actual conduct of 
international trade do commodities thus move now one way, now 
the other? 
In answer to questions of this kind it must be admitted at once 
that all abstract economic theory, and especially economic theory 
of the type illustrated in the preceding chapters, provides nothing 
more than working hypotheses. The process is no more than a 
preliminary approach toward principles and established conclu- 
sions. I would not belittle the importance of these first steps. 
Procedure such as they typify is indispensable in all scientific 
investigation. But they are no more than first steps. What 
we are concerned with at the end is the understanding of the 
phenomena of the actual world. Until we test and verify the 
hypotheses, we have no theory of international trade; we have 
no more than prolegomena to a theory. The task of verification 
has been too much neglected, not only as regards international 
trade, but as regards all the problems of exchange and distribu- 
tion. The neglect is explicable on various grounds; partly the 
intellectual neatness and apparent conclusiveness of the deduced 
conclusions, largely the lack of descriptive and statistical material 
of a kind serviceable for the purposes of verification. The avail- 
able material, however, is becoming steadily more abundant and 
more serviceable. Tho far from fully adequate, it is certain to be 
greatly enriched with the progress of descriptive economics and of 
statistical science. Even as it stands, not a little can be done; 
enough to clothe the dry bones with some flesh and blood, to give 
some indication of the degree of validity which appears when the 
deduced formulae are compared with the concrete phenomena of 
trade between nations. The present Book will be devoted to such 
comparisons — to problems of verification. 
Some sort of verification is supplied by attentive observation of 
familiar phenomena. Most patent of all is that derived from the 
relation of imports and exports; the tendency to an equality of 
money values between them; the mechanism of the foreign ex- 
changes, the comparatively small flow of specie which in fact takes