THE RELATION BETWEEN STATICS AND DYNAMICS 47 
differs from statics not merely in its conclusions but also in its 
problems. 
In pursuing this question we shall first look at the origin of 
statics, finding it in one out of a considerable number of prob- 
lems with which classical economics dealt. The development, 
however, of a complete static society, causes statics to reach out 
into the realms of the other problems, where this static method 
of approach is not so clearly indicated. It also appears that the 
conclusion of the more developed statics—the level of static 
equilibrium—is, in the earlier forms of the study, essentially an 
assumption based on observation; and the assumptions of the 
later form of the theory are, in a real sense, deduced from it, 
being the conditions necessary to bring it about. Thus the rela- 
tions of premise to conclusion may with propriety be reversed, 
or the entire structure be regarded as an assumption, to be justi- 
fied by its usefulness in interpreting facts of experience. 
So far as dynamic conditions differ from static in mechanical 
ways only, static conclusions may be converted into dynamic 
by quantitative allowances; but so far as the differences are 
qualitative or “chemical” in character—to use the figure employed 
by John Stuart Mill,* the more far-reaching methods are indi- 
cated, and new inductions are likely to be necessary. 
In examining the assumptions proper to dynamics, these are 
found in many cases to differ from static premises in qualitative 
or “chemical” ways; including the dynamic character of human 
nature and the evolution of institutions. The result is to broaden 
the scope and modify the character of the study. The work of 
J. B. Clark includes examples of both the narrower deductive and 
the broader qualitative modifications of statics. The former 
are found in his Essentials of Economic Theory, while the most 
challenging fragments of the broader type of study are contained 
in his earlier work: The Philosophy of Wealth. 
If dynamics must be built largely by new inductions, what will 
be left of statics? In the first place, dynamics will never answer 
all its problems, and the static answers, provisional as they are, 
will to that extent continue to fill their former place. In the 
second place, in relation to the original static problem of levels 
of prices, much can be done by quantitative modifications of 
1 John Stuart Mill: A System of Logic, Book III, Chap. VI; Book VI, 
Chap VAL ol _ B. Clark also uses this figure. See The Philosophy of