10 LAWS OF ENERGY 



the circumstances, give relief from strain with the least possible 

 expenditure of energy. When a state of strain is made more 

 or less permanent, the organism readjusts itself to meet the 

 strain. That is, the easiest course is not to remove the cause 

 of strain, but to make such an alteration in itself as shall render 

 the external change innocuous. This is the principle underlying 

 the theory of adaptability. A tree arranges its branches so as to 

 offer least resistance to the prevailing wind. Other examples 

 might be drawn from the sciences of physiology, economics, 

 psychology and ethics. 



Physiology. The introduction of an irritating substance into 

 the alimentary canal causes vomiting to remove the cause of 

 irritation, i.e. to relieve strain. Some less exhausting means of 

 relieving strain has to be taken to meet the more or less con- 

 tinuous administration of poison. The cells of the organism so 

 alter as to be immune from such irritation. Mithridates is said 

 to have qualified for the throne of Pontus by the ingestion of 

 all sorts of poisons in his youth. 



Economics. The law of supply and demand, rates of ex- 

 change, etc., are merely restatements of this principle of least 

 action. 



Psychology and Ethics. The unjust judge met the early appeals 

 of the widow with a firm refusal. His mind was relieved, his 

 case settled. Because of her very importunity, persistent strain 

 was set up which had to be relieved by reopening the case and 

 giving a just decision. 



Enough has been said to show the possibilities of this deduc- 

 tion from the second law of energetics. The thorough-going 

 mechanist states that this law of least action is the principle 

 governing the action of living as well as dead matter. 



All action, it is said, is a response to stimulus, and is such as 

 will most permanently and with " least action " relieve the state 

 of strain. The mechanist denies any cause of action but this. 

 What has been taken for the effect of will or instinct is in reality 

 the effect of light, of gravity, of friction, of chemical force, or of 

 some other known or knowable external force. In short, some 

 alteration in an external factor has brought about an instability 

 in the physico-chemical equilibrium of the object or of the 

 organism, and thus a shift in the equilibrium will take place in 

 such a direction as to decrease the magnitude of the alteration 

 which would otherwise occur. The animal, human or otherwise, 

 is but a machine, working according to physico-chemical principles, 



