Vol. 7, 1921 
BIOLOGY: A. J. LOTKA 
195 
Furthermore, in the competition which takes place among organisms, 
the advantage must go to those whose energy-capturing devices are most 
effective in directing available energy into such channels as are favorable 
to the preservation of the species. 
In man, as an organism of the animal type, the mechanism for capturing 
available energy comprises three elements : 
1. Sense Organs, or Receptors, whose function is to establish a certain 
rather close correlation between the state of the environment and that 
of the individual. Their function, in fact, is to depict the external world 
in the organism, to apprise him of the state of his environment. 
2. Organs of Operation, or Effectors, such as hands, feet, etc., by means 
of which the individual reacts physically upon his environment so as to 
modify it, or to modify his relation to it (as, for instance, by locomotion) . 
3. Organs and Faculties of Adjustment, or Adjustors, whereby the 
action of the Effectors is adjusted in accordance with the indications 
furnished by the sense organs (receptors), and with the needs of the or- 
ganism. 
Among these adjustor faculties one which figures prominently and 
.plays an important role is what we may call the sense of values, that 
faculty which we exercise when we are confronted with two or more alter- 
native courses of action, from which one must be selected. In such a 
situation we choose the course which appears to us, subjectively, the 
more desirable, and we do not ordinarily give any thought to the question 
as to what may be, objectively, the significance of "desirability," any 
more than we do ordinarily concern ourselves, in viewing a landscape, as 
to the particular wave-length, the objective characteristic, of the light 
which to our subjective judgment appears "green." 
And yet, for the interest of the species, it is evidently far from indif- 
ferent what may be the objective characteristics of those things which to 
us appear, subjectively, desirable. Upon the proper adjustment of the 
sense of values, of the "tastes," to certain objective realities depends the 
welfare of the species. A nation of drunkards, for example, is not destined 
to figure among the winners in the struggle of evolution. 
If, then, the physicist has been interested in discovering the objective 
significance of the indications of our sense organs, if he has thought it 
within his province to investigate the relation between color and wave- 
length, between musical pitch and frequency, then it is equally a problem 
for the physicist to enquire into the physical basis of economic value. 
The ground has been prepared for this enquiry by the mathematical 
economists in their hedonistic calculus. A person having at his disposal 
a given sum of money, and being confronted with the necessity of choosing 
between different ways of spending it, will seek so to apportion his ex- 
