On Scientific Method . 
497 
1877=] 
law. But by us, at any rate, various laws must be recognised ; 
and these are mutually related. Now if we cannot hope to 
know all the fadds of the Universe still less can we hope to 
comprehend all the laws thereof, and much less can we dream 
of arriving at a knowledge of the mutual actions of those 
laws upon one another, and the modifications in the addion 
of one law upon material objedds introduced by the inter- 
ference of another law, or of other laws. And even our 
knowledge of individual laws is but approximative : the more 
carefully Nature is examined the more reason have we for 
disbelieving in the simplicity of her addions. At first every- 
thing appears chaotic ; then fadds group themselves together, 
generalisations are made, laws are framed. But after a time, 
as investigation proceeds, and as more exadd methods are 
introduced, the law is found to be not quite in keeping with 
fadds ; the formula was only approximately true. There are 
slight exceptions, so slight that the older and ruder methods 
of research failed to detedd them : the law is not rigorously 
exadd. In the hands of the trained and able naturalist these 
small exceptions often prove stepping-stones to higher gene- 
ralisations, which embrace in their enunciation the less 
widely applicable generalisation. But if every improvement 
in our methods of research serves to point out exceptions to 
what were formerly accepted as general laws, are we entitled 
to assume that we ha venow reached the true generalisation ? 
Would it not be more becoming the spirit of true science to 
acknowledge our ignorance, to remember that while we have 
made one step nearer the goal that goal is itself still at an 
infinite distance from us ? 
I might illustrate this subjedd by reference to the researches 
of Caigniard de la Tour and Andrews upon the physical pro- 
perties of gases, wherein it is shown that the laws in which 
Boyle, Marriott, and former experimenters enunciated the 
results of apparently complete investigations into the same 
subjedd were really only approximations to a solution of the 
problem. More recently Mendelejeff has shown, by very re- 
fined and laborious experiments, that Boyle’s law is not 
stridtly true, and he has paved the way for a higher generali- 
sation. But space forbids me to enter into these details. 
We generally regard a well established physical law as 
adding continuously throughout all past time. Of course 
this is merely an assumption, yet it is an assumption which 
is apparently necessary in most cases if we are to attempt a 
scientific solution of the problems of the Universe. But 
there are good reasons for believing that certain very well 
VOL. VII, (N.S.) 3 M 
