THE THEORY OF DESCENT 275 



safeguard any sort of improvement which chance may 

 effect in this primitive " eye." Such a view is said to hold 

 well with respect to the origin of every new organ. And 

 this psychological argument is also said to afford the real 

 explanation of adaptation proper. Adaptation also is 

 regarded not as a truly primary faculty of the organism, 

 but as a retention or provoking of metabolic states which 

 occurred by accident originally and were then found to be 

 useful ; now they are reproduced either in every single 

 case of individual morphogenesis, without regard to actual 

 requirements, or else only in response to such : in the first 

 case they are " inherited," in the second they only occur as 

 regulations. Thus the process of judgment, together with 

 all the other elemental factors of psychical life concerned in 

 it, has been made to account for adaptation proper. The 

 whole theory has accordingly become very uniform and simple. 



CRITICISM OF THE " INHERITANCE OF ACQUIRED CHARACTERS ' 



ASSUMED BY LAMARCKISM 



In addressing ourselves to the criticism of Neo-Lamarckism 

 we shall neglect as far as possible all the different psycho- 

 logical principles concerned in it which in any case would 

 need rather a great amount of epistemological sifting and 

 shall keep to those hypothetic facts which are supposed to 

 be such as may be actually observed in nature. 



All of you know that the so-called inheritance of 

 acquired characters lies at the root of Larnarckisni ; and 

 from this hypothesis our critical analysis is to start, 

 disregarding a larger or smaller number of psychological 

 principles that are brought into the field. 



