WHAT IS EVOLUTION? 55 



to keep speculation in its proper place as distinct 

 from science ; and secondly, to teach the known facts 

 and principles of science widely, so that the general 

 mind may bring its common-sense to bear on any 

 hypothesis which may be suggested. Speculations as 

 to origins may have some utility if they are held 

 merely as provisional or suggestive hypotheses. They 

 become mischievous when they are introduced into 

 text-books and popular discourses, and are thus 

 palmed off on the ignorant and unsuspecting for what 

 they are not. 



The man who, in a popular address or in a text 

 book, introduces the descent of species as a proved 

 result of science, to be used in framing classifications 

 and in constructing theories, is leaving the firm 

 ground of nature and taking up a position which ex 

 poses him to the suspicion of being a dupe or a 

 charlatan. 1 He is uttering counterfeits of nature s 

 currency. It should not be left to theologians to 

 expose him , for it is as much the interest of the 

 honest worker in science to do this as it is that of the 

 banker or merchant to expose the impostor who has 

 forged another s signature. In the true interests of 



1 I am glad to observe that Huxley, in the preface to the Manual 

 of the Anatomy of the Invertebrated Animals (1878), has taken this 

 ground. He says : * I have abstained from discussing questions of 

 aetiology, not because I underestimate their importance, or am in 

 sensible to the interest of the great problem of evolution, but because, 

 in my mind, the growing tendency to mix up setiological speculations 

 with morphological generalisations will, if unchecked, throw biology 

 into confusion. 



