632 POPULAR SCIENCE MONTHLY. 



MENTAL ENERGY.* 



By EDWARD ATKINSON. 



ACCORDING to the common conception, political economy is held to 

 ■ deal with material forces only; with land, labor and capital; with 

 the production, distribution and consumption of the materials of 

 human existence. These are food, clothing and shelter. It, there- 

 fore, bears the aspect of a purely material study of material forces. Yet 

 no more purely metaphysical science exists, and there can be, in my 

 view of the subject, no more ideal conceptions than those which are 

 derived from the study of these purely material forces. Many of the 

 errors commonly presented under the name of the 'claims of labor' have 

 arisen from the limited and partial conception of the function of 

 economic science. 



We have become accustomed to deal with the so-called material 

 forces of nature and with the physical work and labor of man under 

 the general term of 'Energy*. What man does by his own labor or 

 physical energy is to convert the products of land and sea, of mine and 

 forest, into new forms from which he derives shelter, food and clothing. 

 In a material sense all that any one can get in or out of life, be he rich 

 or poor, is what we call our board and clothing. Such being the fact, 

 what a man consumes is his cost to the community; what he spends 

 yields to others the means of buying the supplies for their own wants; 

 their consumption is then their cost to the community. 



The physical forces of nature are limited. The earth is endowed 

 with a fixed quantity of materials that we call gaseous, liquid and solid. 

 It receives a certain amount of heat from the sun which, for all prac- 

 tical purposes, may be considered a fixed quantity of energy, even if 

 in eons it may be exhausted. The physical energy of man is devoted to 

 the transformation of these physical forces under the law of con- 

 servation; he can neither add to nor diminish the quantity. He can 

 transform solid into gas and gas into liquid. He can, according to com- 

 mon speech, consume some of these products, but his consumption is 

 only another transformation. His own body is but one of the forms of 

 physical energy on the way toward another form. These elements of 

 nature, formerly limited to earth, air and water, are now listed under 

 many titles of what are called elements; I believe over sixty that have 

 not yet been differentiated, but all may yet be resolved into a unit of 

 force. 



* Presented before the New York meeting of the American Association for the Advancement 

 of Science. 



