IV PBEFACE. 



mean nothing more nor less than that man's " nature " 

 is far more complex than could be inferred from any- 

 thing we are able to learn through what is commonly 

 understood by the descriptive phrase "Natural Science." 



At the same time, the results in this particular field 

 of inquiry show a vitality in the method of inquiry 

 through which the results are obtained, that could not 

 be lightly esteemed. Indeed, the more I learned of the 

 "speculative" method of inquiry on the one hand, and 

 of the method of inquiry in Natural Science on the other, 

 the more did it appear to me that so far as men really 

 think, the method of their thinking not only must 

 prove, but actually does prove, to be one and the same. 

 The method may be consciously pursued, and thus may, 

 or rather must, itself become the object of investiga- 

 tion in which case it shows itself as explicitly " specu- 

 lative;" or, on the other hand, it may be unconsciously 

 pursued and applied (for example) in the investigation 

 of physical phenomena; in which case it is still "specu- 

 lative," though it is so only implicitly its form here 

 being that of "hypothesis." 



It appeared, then, that in the scientific movement of 

 the present time we have the conspicuous external 

 counterpart, or rather complement, of the speculative 

 movement, which first assumed an explicit scientific 

 character with the Greek schools of thought, and which 

 again developed into special vigor and effectiveness in 

 Germany during the closing years of last century and 

 the first quarter of the present. 



