10 ADDRESS OF 



if 



they are connected. In this work we have to be concerned with 

 two things ; the general laws of nature, as they are familiarly 

 called, and the facts or circumstances which determine the oper- 

 ation of these laws. This distinction is most clearly seen in hu- 

 man laws. Thou shalt not steal, is a law ; that John has stolen, 

 is a fact. The 1 combined result of the law and the fact is that 

 John is locked up in jail. So, that all bodies near the earth gravi- 

 tate toward it with a force directly as their mass, and inversely as 

 the square of their existence from its centre, is a universal law of 

 nature. The Niagara river and the precipice are facts ; and the 

 cataract is the result. 



But the general explanation of the course of nature, on the me- 

 chanical theory, is not of this simple kind, because the laws of 

 nature do not act singly, but in combination ; so that the result of 

 each is modified by the action of all the others which come into 

 play. The law of gravitation is not that all bodies must fall, but 

 only that they tend to fall, and, therefore, will fall unless held up 

 by some sufficient opposing force. So long as I support this weight 

 in my hand it does not fall, because the force of gravitation and 

 the resistance of my hand neutralize each other. But the instant 

 I let go, the weight drops, according to' a certain law known as 

 that of uniformly accelerated velocity. 



The doctrine I am endeavoring to elucidate is this : knowing a 

 few simple laws of nature, of which gravitation is one ; knowing 

 also the arrangement of material things within the field of investi- 

 gation ; that is, knowing the facts, we can predict with unerring 

 certainty what the result will be : .Or if we cannot predict it, it is 

 not because of any quality of the thing itself, but only because of 

 the insufficiency of our powers. Moreover, these results will be, as 

 it were, another layer of facts, from which it is possible to. predict 

 new results to follow them, and so on without limit, unless some 

 force from without intervene to change the course. If we include 

 the whole of nature in our field, no outside facts can come in, and 

 her course, therefore, admits of being predicted with entire cer- 

 tainty from beginning to end. 



Now the point which I wish to bring to your attention is, the 

 revolution which modern science has brought to pass, in the opin- 

 ions of mankind, respecting the relations of the two classes of 

 causes, or supposed causes, which I have described. That all 

 events could be explained on teleological principles, it is not 



