484 FRAGMENTS OF SCIENCE. 
different individuals of the same race. AYere there not in 
the human brain 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 than 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^ wEIcTi He~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 ou Light," No, HI, 
