IGNORABLMUS ET RESTRINGAMUR. 103 



passes over the most important part of his subject is 

 truly surprising; as if it were ultimately indifferent 

 whether we have before us one single insoluble funda- 

 mental problem or two quite different ones ; and as if 

 mature reflection did not lead to the conviction that, 

 in fact, the second problem is only a special case of the 

 first general problem. I, for my part, cannot conceive 

 of them in any other relation ; I think, too, that all 

 further words are by no means superfluous, but on the 

 contrary conduce to a very strong conviction of the 

 unity of the problem. That Du Bois-Eeymond also 

 has not come to any clear conclusion on this point 

 lies, not alone in the " nature of things," but, as in 

 Yirchow's case, in the nature of the investigator him- 

 self; in his lack of knowledge of the history of 

 evolution, and in his neglect of those comparative 

 and genetic methods of study, without which, in my 

 opinion, not even an approximate solution of this 

 highest and most difficult question is to be looked 

 for. 



Nothing appears to me to be of more importance 

 for the mechanical explanation of consciousness than 

 the comparative consideration of its development. We 

 know that a new-born child has no consciousness, but 

 that it is slowly and gradually acquired and developed. 

 We perceive for ourselves how unconscious actions 

 become conscious, and vice versa. Innumerable actions 



