MECHANISM AND VITALISM 



411 



of mercury, the previous history of the gel can be told. This 

 variation of a material with its past, which is the essence of hered- 

 ity, is here shown by inorganic materials. 



The vitalists have admitted in some of the above cases that the 

 mechanists have defined the essence of an attribute correctly and 

 have reproduced it in the inorganic world. They have thus, to 

 some extent, been forced to retreat from their positions. In other 

 cases, they have refused to concede these points. These matters 

 are critical and are questions which every observer must decide 



Fig. 29. — Water content of a silicic acid gel in equilibrium with varying 

 tensions of water vapor. From the water content when the mercury vapor 

 tension is 6.3 mm. one can tell whether the previous history of the gel has been 

 one of an increasing or decreasing vapor tension. (After Van Bemmelen.) 



for himself: (1) Have the mechanists defined correctly the es- 

 sential character of the process? and (2) is their imitation of it a 

 correct analogy? 



Modern Mechanism. — Modern mechanism has led into two 

 distinct fields,— biology and psychology. In biology its advance 

 has been more or less gradual as more barriers have progressively 

 yielded to physicochemical methods. In psychology, modern 

 mechanism has led to determinism. If all acts are the result of 

 the operation of physicochemical laws, then there is no freedom 

 of the will and responsibility in the old sense must disappear. 

 What seems to be free will or an exercise of discretion is merely an 

 illusion. We think we are choosing but we are not. Our choice is 

 an inevitable one as a result of the reactions which have gone be- 

 fore. When we decide to do the right thing in a time of crisis, 

 if the doctrine of determinism is correct, the only reason why we 



