600 PHILOSOPHICAL THOUGHT. 



ally been identified with the problem of the nature and 

 origin of life or animation, and it is significant that 

 Herbert Spencer himself, in one of his latest deliverances, 

 admits the insolubility of this problem. 1 



In the second address mentioned above, Du Bois 

 Reymond further analysed the two enigmas which 

 respectively have to do with the most elementary, or 

 molar, and the most complicated, or mental, phenomena 

 into a larger number of definite problems. Of these he 

 details seven. Four of them, the essence of matter 

 and force, the origin of motion, the elementary sensa- 

 tions, the freedom of the Will, are declared to be in- 

 soluble. The further three problems : the origin of life, 

 the apparent purpose in nature, and the origin of 

 language, he does not hold to be eventually equally 

 insoluble, though they are so at present. His view can 

 be defined by saying that the mechanism which suffices to 

 explain the processes in inorganic nature and plant-life 

 does not suffice for the processes of sensation and conscious- 

 ness : the latter bring into biological development some- 

 thing new, which, as an epiphenomenon, rises out of the 

 inner essence or nature of matter. Du Bois Reymond, 

 however, significantly allows the assumption that these 

 different problems or enigmas may be essentially one, 

 thus approaching still nearer to Herbert Spencer's view. 

 40. A speculation somewhat on the same lines had already 



Haeckel's 



Monism. been started by Ernst Haeckel in his first and greatest 

 work, the ' Generelle Morphologic.' As this work had 

 only a moderate circulation, he further expounded and 

 popularised his philosophical creed in a series of writings, 



1 See supra, vol. ii. p. 438. 



