54 ECONOMIC ESSAYS IN HONOR OF JOHN BATES CLARK 
an approximate relation between price and utility, the theory 
is true. While it is, as has been said, a natural derivative from 
the Bentham psychology, it does not depend on the “calculus 
of pleasure and pain,” but can be presented in terms of any 
other description of human motives; so long as the motives 
behave in a certain way. The essential assumption is that the 
individual has a scale of values or preferences: good or bad, 
wise or foolish, conscious or unconscious; and that his various 
economic acts are the expressions of this one scale of values.’ 
They are consistent; the scale holds while he is making the 
various decisions which are involved in the budgeting of his 
time, energy and resources.” Thus the values in his personal 
economy reach an equilibrium which is the parallel of the static 
equilibrium of prices in a market. This fact is expressed either 
as an actual tendency, or as an ideal of good personal manage- 
ment. As indicated, it has sufficient truth to justify its place 
in a static economics, being itself a static assumption. 
In contrast, in the attempt to put together the most realistic 
picture of human nature for which the materials are readily 
available, one is struck by its prevailing dynamic character. 
It contains static elements, but they differ essentially from the 
static character of the marginal-utility assumption. 
Man is a mechanism of stimulus and response, conditioned 
not only by the present stimuli to which he may be exposed, 
but by past stimuli which have played their part in shaping 
the personality with which he now responds. Desires and ideas 
are not separate, but ideas are themselves impulses to action. 
Deliberative choice—the nearest approach to the rational action 
of theory—is a check on this tendency to act on the immediate 
stimulus, and a very imperfect check. Even the static ele- 
ments of instinct or inborn tendency, habit and custom, change 
their quality when placed in a changing environment. Adapted 
to a past environment, they may be unadapted to the present, 
1 No consideration is here given to that form of the utility theory which 
attempts to be completely agnostic as to how human choices behave and 
to deal only with momentary preferences. But the writer believes that 
this type of theory acquires meaning just so far as there is attached to it 
some premise as to how choices actually do behave. 
2 The writer has elsewhere gone into this point in more detail. See 
«Economics and Modern Psychology,” Jour. of Pol. Econ., 26; 1-30, 136-66 ; 
Jan.-Feb., 1918. These articles contain the material on which this entire 
section is based.