42 DISCOURSE ON THE STUDY 



(32.) Now, this absolute indestructibility of the 

 ultimate materials of the world, in periods commen- 

 surate to our experience, and their obstinate reten- 

 tion of the same properties, under whatever variety 

 of circumstances we choose to place them, however 

 violent and seemingly contradictory to their natures, 

 is, of itself, enough to render it highly improbable 

 that time alone should have any influence over 

 them. All that age or decay can do seems to be 

 included in a wasting of parts which are only dissi- 

 pated, not destroyed, or in a change of sensible pro- 

 perties, which chemistry demonstrates to arise only 

 from new combinations of the same ingredients. 

 But, after all, the question is one entirely of expe- 

 rience : we cannot be sure, a priori, that the laws 

 of nature are immutable ; but we can ascertain, by 

 enquiry, whether they change or not; and to this 

 enquiry all experience answers in the negative. It 

 is not, of course, intended here to deny that great 

 operations, productive of extensive changes in the 

 visible state of nature, such as, for instance, those 

 contemplated by the geologists, and embracing for 

 their completion vast periods of time, are con- 

 stantly going on ; but these are consequences and 

 fulfilments of the laws of nature, not contradictions 

 or exceptions to them. No theorist regards such 

 changes as alterations in the fundamental principles 

 of nature; he only endeavours to reconcile them, 

 and show how they result from laws already known, 

 and judges of the correctness of his theory by 

 their ultimate agreement. 



(33.) But the laws of nature are not only per- 

 manent, but consistent, intelligible, and discoverable 



