484 FRAGMENTS OF SCIENCti. 



different individuals of the same race. Were there not in 

 the human braiu a potency antecedent to all experience, 

 a dog or a calf ought to be as capable of education as a 

 man. These predetermined internal relations are inde- 

 pendent of the experiences of the individual. The human 

 brain is the "organized register of infinitely numerous 

 experiences received during the evolution of life, or rather 

 during the evolution of that series of organisms through 

 which the human organism has been reached. The effects 

 of the most uniform and frequent of these experiences have 

 been successively bequeathed, principal and interest, and 

 have slowly mounted to that high intelligence which lies 

 latent in the brain of the infant. Thus it happens that the 

 European inherits from twenty to thirty cubic inches more 

 of brain thuu the Papuan. Thus it happens that faculties, 

 as of music, which scarcely exist in some inferior races, 

 become congenital in superior ones. Thus it happens that 

 out of savages unable to count up to the number of their 

 fingers, and speaking a language containing only nouns 

 and verbs, arise at length our Newtons and Shakspeares." 



SECTION" 8. At the outset of this address it was stated 

 that physical theories which lie beyond experience are 

 derived by a process of abstraction from experience. It is 

 instructive to note from this point of view the successive 

 introduction of new conceptions. The idea of the attrac- 

 tion of gravitation was preceded by the observation of the 

 attraction of iron by a magnet, and of light bodies by 

 rubbed amber. The polarity of magnetism and electricity 

 also appealed to the senses. It thus became the sub- 

 stratum of the conception that atoms and molecules are 

 endowed with attractive and repellent poles, by the play 

 of which definite forms of crystalline architecture are pro- 

 duced. Thus molecular force becomes structural* It 

 required no great boldness of thought to extend its play 

 into organic nature, and to recognize in molecular force 

 the agency by which both plants and animals are built 

 up. In this way, out of experience arise conceptions which 

 are wholly ultra-experiential. None of the atomists of antiq- 

 uity had any notion of this play of molecular polar force, 

 but they had experience of gravity, as manifested by fall- 



* See Art. on Matter and Force, or " Lectures on Light," No. III. 



