246 THE RIDDLE OF THE UNIVERSE. 



that the world had had a beginning. Hence, according 

 to a widespread version of the nebular hypothesis, " in 

 the beginning" was made a vast nebula of infinitely 

 attenuated and light material, and at a certain moment 

 ("countless ages ago") a movement of rotation was 

 imparted to this mass. Given this " first beginning " 

 of the cosmogonic movement, it is easy, on mechanical 

 principles, to deduce and mathematically establish the 

 further phenomena of the formation of the cosmic 

 bodies, the separation of the planets, and so forth. 

 This first " origin of movement " is Du Bois-Reymond's 

 second "world-enigma"; he regards it as transcen- 

 dental. Many other scientists and philosophers are 

 equally helpless before this difficulty ; they resign 

 themselves to the notion that we have here a primary 

 " supernatural impetus " to the scheme of things, a 

 " miracle." 



In our opinion, this second "world-enigma" is 

 solved by the recognition that movement is as innate 

 and original a property of substance as is sensation. 

 The proof of this monistic assumption is found, first, 

 in the law of substance, and, secondly, in the dis- 

 coveries which astronomy and physics have made in 

 the latter half of the century. By the spectrum 

 analysis of Bunsen and Kirchhoff (1860) we have 

 found, not only that the millions of bodies, which fill 

 the infinity of space, are of the same material as our 

 own sun and earth, but also that they are in various 

 stages of evolution ; we have obtained by its aid infor- 

 mation as to the movements and distances of the stars, 

 which the telescope would never have given us. 

 Moreover, the telescope itself has been vastly improved, 

 and has, in alliance with photography, made a host of 

 scientific discoveries of which no one dreamed at the 



