. 546 SCIENTIFIC THOUGHT. 



tinct views have been evolved by modern science on 

 this matter. 



The one emphasises the fact of the discontinuity of 

 mental i.e., conscious life, regards it as an ultimate 

 fact, as a mystery beyond which we cannot travel. This 

 idea presents itself in various forms, and has been 

 notably insisted on with very varying philosophical 

 inferences by Du Bois-Eeymond in Germany, by Mr 

 A. R. Wallace, and quite recently by the late Prof. St 

 George Mivart in England. 



The other takes refuge in the hypothesis of un- 

 conscious or subconscious mental life, and again with 

 very different philosophical inferences assumes that all 

 physical existence has an inner side which only under 

 certain favourable conditions rises into the light of self- 

 knowledge or consciousness. The late W. K. Clifford's 

 "mind-stuff" theory, as also the speculations of Fechner 

 and of Prof. Haeckel, are types of this view, which has 

 been consistently and connectedly elaborated in Hart- 

 mann's ' Philosophy of the Unconscious.' 



These speculations can be summed up under the title 

 " The Creed of Science," and as such will occupy us later 

 on in one of the chapters on the Philosophical Thought 

 of the century. 



By many natural philosophers it is felt that the time 

 has not yet come to arrive scientifically at any definite 

 51. conclusions on these last questions. Sufficient facts have 

 not been collected ; or even if collected, they have not 

 yet been classified and tabulated. This is especially the 

 case with the vast materials referring to the collective 

 life of mankind. Leibniz had in his time foretold the 



