i 4 SCIENCE PRIMERS. [NATURE AND 



natural objects will do under certain circumstances. 

 Each contains information addressed to our intelligence, 

 and except so far as it influences our intelligence, it is 

 merely so much sound or writing. 



While there is this much analogy between human 

 and natural laws, however, certain essential differences 

 between the two must not be overlooked. Human 

 law consists of commands addressed to voluntary 

 agents, which *they may obey or disobey ; and the 

 law is not rendered null and void by being broken. 

 Natural laws, on the other hand, are not commands 

 but assertions respecting the invariable order of 

 nature ; and they remain laws only so long as they 

 can be shown to express that order. To speak of the 

 violation, or the suspension, of a law of nature is an 

 absurdity. All that the phrase can really mean is 

 that, under certain circumstances the assertion con- 

 tained in the law is not true ; and the just conclusion 

 is, not that the order of nature is interrupted, but 

 that we have made a mistake in stating that order. 

 A true natural law is an universal rule, and, as such, 

 admits of no exceptions. 



Again, human laws have no meaning apart from the 

 existence of human society. Natural laws express the 

 general course of nature, of which human society 

 forms only an insignificant fraction. 



10. Knowledge of Nature is the Guide of 

 Practical Conduct. 



If nothing happens by chance, but everything in 

 nature follows a definite order, and if the laws of 

 nature embody that which we have been able to learn 



