No. 359] 



DOCTRINES HELD AS VITALISM 



405 



how, the non-perceptual agent takes part in the process. 

 This being so, it would evidently be impossible from a 

 complete knowledge of all the physical or perceptual con- 

 ditions to predict what would result from a given situa- 

 tion, even after one had once experienced it. In a previ- 

 ous paper, 23 I have characterized as experimental inde 

 termini sm this condition of affairs, in which, in the words 

 of Driesch "Two systems absolutely identical in every 

 physico-chemical respect, may behave differently under 

 absolutely identical conditions, in case that the systems 

 are living systems"; 24 and have pointed out that for the 

 work of the investigator experimental indeterminism 

 presents the same practical situation as would absolute 

 indeterminism. 



39. It would certainly be difficult to imagine a more 

 fundamental difference, either theoretical or practical, 

 between two divisions of science, than that resulting 

 from the acceptance of experimental indeterminism, 

 along with the determining activity of a non-perceptual 

 agent, for the living; science might well be divided into 

 two contrasted parts, vitalistic and non-vitalistic, on 

 such a basis. 25 Furthermore, as I have already set 

 forth, this appears to me the form to which all vitalistic 

 doctrines come, if they make any really valid distinction 

 in principle between the sciences of the living and the 

 non-living. It is perhaps worthy of note in this connec- 

 tion that the two most influential systems of vitalism at 

 the present time— that of Driesch and that of Bergson 

 — are avowedly such systems of indeterminism, either ex- 

 perimental or absolute. 26 



