Teachings of Thomas Huxley 13 



nity in what may be broadly stated its present 

 condition. 



Whether true or false this postulate is not 

 capable of proof by any evidence ; for to prove 

 it you must have either an eternity of witnesses 

 or an infinity of circumstances, either of which 

 is an impossibility. The testimonial evidence 

 is inadequate because the antiquity of human 

 records is relatively nil compared with the age 

 of the earth, hence one is compelled to con- 

 sider the circumstantial evidence alone. This 

 circumstantial evidence is such as we can ob- 

 tain only from a study of the earth's crust, 

 which is composed of strata of sand, stone, clay, 

 slate and numerous other materials. All of 

 these we are constrained to believe are identical 

 with those of the same type at present under 

 formation everywhere about us through the in- 

 fluence of natural agencies. For example, the 

 chalk of the hillside is found upon analysis to 

 be one and the same with that brought up 

 from the bottom of the Atlantic, and must 

 have been formed in precisely the same manner 

 as that which is now forming immediately un- 

 der our eyes. Again, some fossils from archaic 

 rocks are alike in all essentials to the animals 

 and plants we see around us every day of our 

 lives, which are being deposited in the mud of 

 swamps and at the bottom of lakes just as they 

 were deposited in bygone ages of untold length. 

 As we dig deeper, however, into the strata we 



