HUMAN AND ANIMAL EVOLUTION CONTRASTED 7 



It has become more and more evident with each dec- 

 ade that nature's forces are sufficient to account for 

 all natural phenomena, and that these forces act 

 according to definite methods which we call laws. As 

 one after another of the previously mysterious phe- 

 nomena have been thus brought within our compre- 

 hension it has been more and more certain that all 

 of nature's phenomena will in time be explained by 

 natural forces. Further, it has been more and more 

 clearly seen that nature's processes are regular, 

 though they may be slow. The "cataclysms" of 

 earlier science have been forgotten, and in their 

 place we have found constant but persistent forces, 

 slowly but continuously producing the series of 

 changes by which the world has been built. The 

 great Colorado canon was cut out slowly by the 

 same forces that are digging channels for the tiny 

 rivulets by the roadside; and in the same way the 

 other great wonders of nature have been the result 

 of the slow but persistent and ever-present forces 

 of nature. 



Now, it is evident that this line of thought, after 

 it has comprehended the processes by which all other 

 forms of life have been developed, must in time 

 inevitably extend to the origin of man. Just as 

 rapidly as the thought of the day becomes accus- 

 tomed to this conception of the method of nature's 

 action, just so rapidly does it adopt the only view 

 of the origin of the human race that is consistent 

 with this conception. It is thus a general realiza- 

 tion of the uniformity of law that has brought about 

 the general willingness to accept a belief in a natural 

 origin of the human race, a belief which is to-day 

 very general not only among scientists but even 



