EXPLANATION OF LAWS. 527 



into laws more certain, in other words, more universally true 

 than themselves ; they are, in fact, proved not to be themselves 

 laws of nature, the character of which is to be universally true, 

 but results of laws of nature, which may be only true condi- 

 tionally, and for the most part. No difference of this sort exists 

 in the third case ; since here the partial laws are, in fact, the 

 very same law as the general one, and any exception to them 

 would be an exception to it too. 



By all the three processes, the range of deductive science is 

 extended ; since the laws, thus resolved, may be thenceforth 

 deduced demonstratively from the laws into which they are 

 resolved. As already remarked, the same deductive process 

 which proves a law or fact of causation if unknown, serves to 

 explain it when known. 



The word explanation is here used in its philosophical sense. 

 What is called explaining one law of nature by another, is 

 but substituting one mystery for another ; and does nothing 

 to render the general course of nature other than mysterious : 

 we can no more assign a ivhy for the more extensive laws 

 than for the partial ones. The explanation may substitute a 

 mystery which has become familiar, and has grown to seem 

 not mysterious, for one which is still strange. And this is the 

 meaning of explanation, in common parlance. But the process 

 with which we are here concerned often does the very contrary : 

 it resolves a phenomenon with which we are familiar, into one 

 of which we previously knew little or nothing; as when the 

 common fact of the fall of heavy bodies was resolved into the 

 tendency of all particles of matter towards one another. It 

 must be kept constantly in view, therefore, that in science, 

 those who speak of explaining any phenomenon mean (or 

 should mean) pointing out not some more familiar, but merely 

 some more general, phenomenon, of which it is a partial exem- 

 plification ; or some laws of causation which produce it by their 

 joint or successive action, and from which, therefore, its con- 

 ditions may be determined deductively. Every such operation 

 brings us a step nearer towards answering the question which 

 was stated in a previous chapter as comprehending the whole 

 problem of the investigation of nature, viz. What are the fewest 



