THE RELATION BETWEEN STATICS AND DYNAMICS 51 
on the other hand, raises an endless number of problems which 
the static view leaves out of sight, and calls for justification of 
one form of an institution as compared to other possible forms, 
and for a weighing of the interests protected by one definition of 
rights as against the interests protected by another. 
Returning to the questions of welfare and efficiency, their early 
independent character has been vitally affected by two great 
developments. One is the Benthamite utilitarianism and its 
natural sequel, the marginal utility theory of value. The 
other is the development of the search for “natural levels” into 
a substantially complete static picture of society: one in which 
“natural levels” would exist, would be stable, would be attained. 
This hypothetical society has its characteristics and laws of 
efficiency, and of the relation of price to welfare, and thus statics 
enlarges its scope and annexes new ranges of problems. The 
means used to approach the problem of levels of price becomes, 
as a by-product of its own fuller working out, a source of pro- 
visional answers to these other questions which were not origin- 
ally cast in a static mold. Is the static method as appropriate to 
these other questions as to the original one? Without prejudging 
this question, for or against, we should preserve an open-minded 
attitude on it, and be prepared for the possibility of finding that 
dynamic economics may need to reéstablish the autonomous posi- 
tion of these various problems. Not a complete isolation, it goes 
without saying. We should also be prepared to find .old prob- 
lems taking new forms, and new problems arising, suggested by 
the new ranges of data which dynamics forces us to consider. 
3. The Problems of Dynamic Economics 
The key to statics, as we have seen, is a problem: that of levels 
of equilibrium. This is an abstraction based on observation of 
the relative stability of economic values, and of oscillations 
whose behavior suggests a normal level toward which the eco- 
nomic forces of gravity exert their pull. The key to dynamics 
is a different problem: that of processes which do not visibly tend 
to any complete and definable static equilibrium. The impor- 
tance of this shift from the search for levels to the study of 
processes can hardly be overemphasised; it is not less significant 
than the change from static to dynamic conditions. It might be 
interesting to try the experiment of assuming static conditions.