42 GENERAL PHYSIOLOGY 



of lifeless bodies may be derived from the properties of the smallest 

 material elements, atoms endowed with energy, and the question 

 then takes the form : May the phenomena of living bodies also be 

 reduced to the same factors ? 



Vitalism says, no ; a special force, vital force, prevails in organ- 

 isms and induces vital phenomena. Vital force is limited to 

 the world of living matter and is not identical with the chemico- 

 physical forces of lifeless nature. 



These words contain the essence of vitalism. It is interesting 

 to inquire upon what the hypothesis of vitalism rests, and what 

 justification it has. In the above review of the history of physio- 

 logical research, the history of the doctrine of vital force was 

 outlined. It was there seen that the conception arose in connection 

 with the phenomena of irritability, and that it has always been 

 vague and has served chiefly for convenience. This indistinctness 

 regarding it is the chief difficulty in the way of its critical 

 elucidation. If the conception could be sharply defined, it could 

 be treated more easily. 



The claim for a vital force rests solely upon the fact that thus 

 far it has not been possible to reduce certain vital phenomena to 

 chemico-physical principles. Indeed, when the achievements of 

 physiological research were summarised above, the discouraging 

 fact became apparent that the vital phenomena that have been ex- 

 plained are only the gross physical and chemical activities of the 

 body, and that whenever the attempt has been made to show 

 their deeper causes, unsolved problems have always opposed it. 

 Bunge ('94) even asserts : " The more we strive to investigate 

 vital phenomena exhaustively, in many directions, and funda- 

 mentally, the more we come to perceive that events which we 

 believed we could explain physically and chemically are exces- 

 sively intricate and for the present mock at all mechanical 

 explanation." 



Although the fact is to be little doubted, that thus far, many, 

 especially the elementary and general vital phenomena have 

 defied all chemico-physical explanation, the assertion is not, 

 therefore, logically justified, that these phenomena do not follow 

 chemico-physical laws at all, but that a special vital force exists 

 and causes them. Moreover, there are facts that speak against 

 the existence of such a force. 



In spite of all endeavours thus far, the vitalists have not 

 succeeded in establishing the existence of any special force in 

 organisms, i.e., they have not been able to characterise such a force 

 from its effects, as physics and chemistry have done for the forces 

 of inorganic nature. With regard to none of the actions of the 

 body supposed to be due to a vital force, have they been able to 

 contradict the assertion that such actions are only the expression 

 of complex chemico-physical relations. E.g., it was long believed 



