550 THE LAWS OF NATURE. 



of nature, and at least as great a generalization as the kinetic theory 

 of gases is to us; as widely accepted, as lirnil}' believed and as cer- 

 tainly known — but what has become of it now'^ 



Can we tell, then, in advance, by any criterion, what a ' law of 

 nature' is? 



With a curious begging of the question some answer, ' Yes, for laws 

 of nature have this distinction, that thev have never been disproved.' 

 As if one were to sa}' , Yes, because when the}" are disproved we deny 

 that the}" are laws of nature! 



Those of us who are capable of being instructed or warned l)y the 

 history of human thought ma}", then, ask what kind of a guarantee 

 are we to have for any other ' fact" of our new knowledge? May they 

 not — all these 'facts' — be gone like the ])aseless fabric of this vision, 

 before another hundred years are passed? 



The physical sciences seem to have had less change in their theories 

 than the mighty displacements in other branches of natural knowledge, 

 but it is a truism to say that all are changed, and it should be a truism 

 to add that the •■ laws of nature ' are not to us what they were a hun- 

 dred years ago. 



1 repeat that of the 'order' of nature we may possibly know a little; 

 but what are these ' laws ' of nature ? What celestial act of congress 

 fixed them? In what statute book do we read them? What guaran- 

 tees them? Our mistake is in believing that there is any such thing, 

 apart from our own fallible judgment, for the thing which the ' laws 

 of natur*;' most absolutely forbid one generation to believe, if it only 

 actually happens, is accepted as a part of them by the succeeding. 



Suppose that a century ago, in the year 1802, certain French 

 Academicians, believing like everyone else then in the ' laws of 

 nature,' were invited, in the light of the best scientific knowledge of 

 the day, to name the most grotesque and outrageous violation of them 

 which the human mind could conceive. I may suppose them to reply, 

 'if a cartload of l)lack stones were to tumble out of the l)lue sky above 

 us, before our eyes, in this very France, we should call that a violation 

 of the laws of nature, indeed!' Yet the next year, not one, but many, 

 cartloads of black stones did tumble out of the blue sky, not in some 

 far off land, but in France itself. 



It is of interest to ask what became of the 'laws of nature' after 

 such a terrible blow. The 'laws of nature' were adjusted, and after 

 being enlarged Vjy a little patching, so as to take in the new fact, were 

 found to be just as good as ever! So it is always; when the miracle 

 liaa happened, then and only then it becomes most clear that it was no 

 miracle at all, and that no 'law of nature' has been broken. 



Applying the parable to ourselves then, how shall we deal with 

 new 'facts' which are on trial, things perhaps not wholly demonstrated, 

 yet partly plausible? During the very last generation hypnotism was 



