40 Natural Theology. 



every generation has need to tread the ground for 

 itself. 



Still another difficulty is the fact that objects in 

 nature have so long been familiar that they fail to 

 excite the emotions, or to convince the understand- 

 ing as they ought, and they thus fail to impress us 

 as proof of creative power. They appear in the 

 ordinary course of nature ; and this unchanging 

 course, always referable in the first analysis to the 

 acknowledged forces of the physical world, fails to 

 impress us as the expression of a personal power. 

 The harmony of nature becomes to us like the 

 mysterious notes of the ^olian harp, as the light air 

 touches its strings, and wakes the sweetest music. 

 We have always seen the combinations and changes 

 around us. Or if $ome new and wonderful combina- 

 tion is discovered, we are able to refer it at once to 

 some force already well known. We content our 

 minds with the word " natural." Whatever is com- 

 mon makes little impression on the senses, or 

 rather the mind ceases to take cognizance of the 

 impressions. Novelty, on the other hand, has a 

 charm that rouses the mind to activity, and this 

 activity is necessary to the full apprehension of the 

 value of the facts and relations upon which we rely 

 for producing conviction of the truth. Aristotle, in 

 a fragment preserved by Cicero in his DE NATURA 

 DEORUM, beautifully illustrates the effect of common 

 things, if seen for the first time. " If," said he, 

 " there were beings who lived in the depths of the 

 earth in dwellings adorned with statues and paint- 



