EXPLAINS NATURAL PHILOSOPHY 157 



and labor lost to attempt to explain the cause of 

 gravity, chemical affinity, and electric and mag- 

 netic attraction and repulsion. 



The atomic theory of the constitution of matter, 

 the conception of an interstellar ether, the undula- 

 tory theory of light and heat were all cast aside as 

 useless and unworthy of notice because they were 

 not directly observable and the senses unaided 

 could not apprehend them. 



According to Comte, the only object of science 

 and philosophy is to observe, record and classify 

 sensible phenomena. What could not be observed 

 by the senses could not be known and did not 

 exist. It is said the only open road to the advance 

 of philosphy was thus forbidden by the man who 

 made the first valuable contribution to its advance- 

 ment. 



Herbert Spencer first undertook the great task of 

 discovering the unifying principle of nature. He 

 recognized all possible phenomena as parts of one 

 great whole, and held that all were united by nat- 

 ural law. He differed from Comte in that he recog- 

 nized the imperceptible as a reality, but made no 

 attempt to explain it or to bring it into harmony 

 with the phenomena of sense, but designated it 

 the unknowable. He divided his system into two 

 general divisions the knowable, which includes all 

 things of sense, experience, and the unknowable, 

 which includes everything else, or the invisible and 

 imperceptible. 



He held the knowable is the proper sphere of 

 man's knowledge or philosophy, and the unknowa- 

 ble the legitimate domain of God and religion. And 

 while he held that God and religion were imper- 



