300 THE FOUNDATIONS OF ZOOLOGY 



associated with another. This second element in the " law of 

 causation" would never have obtained a moment's credence if it 

 were not brought before our minds in intimate relation with the 

 great natural truth of the other element. 



" There are," says Herschel, " truths so large, so general, so 

 all pervading, that they make a part of all our experience, mix 

 with our whole intellectual being, and imbue all our judgments, 

 erroneous as well as correct; in this sense, at least, that we 

 never err so far as to place ourselves in conscious opposition to 

 them. 



" Distorted and perverted as such truths may be in their 

 enunciation, by their mixture with extraneous error, we find them 

 still outstanding, redeeming by their presence and ever conse- 

 crating that error." ^ 



Such a truth I take the law of causation to be. 



All writers on the principles of science agree that man has 

 as yet discovered nothing except a little of the order of nature, 

 and that the reason why events occur in one order rather than 

 another, or even why they occur in any order, is a mystery to 

 which nature gives us no answer; for even if natural selection 

 should show that we should have been different if the selective 

 standard had been different, and that this order is no more than 

 might have been expected from our history, this is no reason 

 why the things we expect should be the things that come about. 



We can say no more about the relation between events and 

 our expectations than that these things appear together, but that 

 nature does not tell us why. If this is true, is it not clear that 

 we are in no position to say of any event that it cannot come 

 about in the absence of any other event, although we may 

 have the utmost practical confidence that it will not come about? 



We cannot well do without the word cause, and Mill has 

 called attention to the obvious fact that the scientific method of 

 investigating cause is independent of metaphysical analysis of what 

 cause means; although exact reasoning about nature is impossible 

 unless this distinction is sharply drawn. A recent writer on 

 logic tells us : "A very simple analysis of ' cause ' is sufficient 

 for the purposes of scientific inquiry. What we call a cause is 



^ Sir J. Herschel, " Essays," p. 270. 



