ENERGETICS 1 1 r 



from the hand to the body. It was formerly held, and is still 

 held bv some physiologists, that the chief characteristic of life 

 is the disproportion between an excitation and the response 

 which it invokes from the organism. Such a doctrine can only 

 be held by one who believes, at least implicitly, that the 

 phenomena of life are supernatural, or at all events different 

 in their nature from all other phenomena; for the dispropor- 

 tion between an excitation and the response it evokes is by 

 no means confined to living tilings. This disproportion is 

 universal in nature, and quite in conformity with the physical 

 laws which govern the transformation of energy. The energy 

 of living things is potential energy — a fact which has been too 

 little recognized. In the case of reflex actions it is self-evident, 

 because the response is immediate, and always the same for the 

 same stimulus. As in all other transformations, the stimulus 

 consists in the intervention of a minimal quantity of external 

 energy. 



Long before the discovery of the laws of energy, Lamarck 

 had recognized and formulated this fact. He writes: "What 



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would vegetable life be without excitations from without, 

 what would be the life even of the lower animals without this 

 cause?" In another passage, seeking for a power capable of 

 exciting the action of the organism, he says: "The lower 

 animal forms, without nervous system, live only by the aid of 

 excitations which they receive from without. In the lowest 

 forms of life this exciting force is borrowed directly from the 

 environment, while in the higher forms the external exciting 

 force is transferred to the interior of the living being and 

 placed at the disposal of the individual." 



This remark, that the movements of living things are not 

 communicated hut excited, that the external excitation only 

 sets free latent or potential energy in the organism, shows 

 that Lamarck had penet.ated i re deeply than many of the 

 modern physiologists into the secrets of biological energy. 

 We seek in vain in the text-books of physiology for any 

 conception of potential energy in living beings, or the notion 

 of an exciting force as the cause of sensation. All action of a 

 living organism is reflex action. Every action has a cause, and 



