TIME AND CHANGE 



doubtless made him the victim of diseases to which 

 the lower orders, and even savage man, are strang- 

 ers. Will not these diseases increase as his life be- 

 comes more and more complex and artificial? Will 

 he go on extending his mastery over Nature and re- 

 fining or suppressing his natural appetites till his 

 original hold upon life is fatally enfeebled? 



It seems as though science ought to save man and 

 prolong his stay on this planet, — it ought to bring 

 him natural salvation, as his religion promises him 

 supernatural salvation. But of course, man's fate 

 is bound up with the fate of the planet and of the 

 biological tree of which he is one of the shoots. 

 Biology is rooted in geology. The higher forms of 

 life did not arbitrarily appear, they flowed out of 

 conditions that were long in maturing; they flow- 

 ered in season, and the flower will fall in season. 

 Man could not have appeared earlier than he did, 

 nor later than he did ; he came out of what went be- 

 fore, and he will go out with what comes after. His 

 coming was natural, and his going will be natural. 

 His period had a beginning, and it will have an end. 

 Natural philosophy leads one to affirm this; but of 

 time measured by human history he may yet have a 

 lease of tens of thousands of years. 



The hazard of the future is a question of both 

 astronomy and geology. That there are cosmic 

 dangers, though infinitely remote, every astronomer 

 knows. That there are collisions between heavenly 



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