Summary and General Conclusions 453 



the field of real scientific work from philosophical speculation. 

 But the outcome has shown that, in general, the philosophi- 

 cal, philological, and aesthetic expression always gets the upper 

 hand, and a fundamental and exact treatment of scientific 

 questions remains limited to a small circle. The public at 

 large always shows a distinct preference for the so-called 

 idealistic, poetic, and speculative modes of expression." The 

 truth of this statement can scarcely be doubted when in our 

 own time we have seen more than once the same method 

 employed with great public applause. Nowhere is this more 

 apparent than in the writings of many of the followers of 

 Darwin in respect to the adaptations of living things. To 

 imagine that a particular organ is useful to its possessor, and 

 to account for its origin because of the imagined benefit con- 

 ferred, is the general procedure of the followers of this school. 

 Although protests have from time to time been raised against 

 this unwarrantable way of settling the matter, they have been 

 largely ignored and forgotten. The fallacy of the argument 

 has, for example, been admirably pointed out by Bateson in 

 the following statement : 1 "In examining cases of variation 

 I have not thought it necessary to speculate on the useful- 

 ness or harmfulness of the variations described. For reasons 

 given in Section II such speculation, whether applied to nor- 

 mal structures or to variation, is barren and profitless. If 

 any one is curious on these questions of Adaptation, he may 

 easily thus exercise his imagination. In any case of Varia- 

 tion there are a hundred ways in which it may be beneficial 

 or detrimental. For instance, if the 'hairy' variety of the 

 moor-hen became established on an island, as many strange 

 varieties have been, I do not doubt that ingenious persons 

 would invite us to see how the hairiness fitted the bird in 

 some special way for life in that island in particular. Their 

 contention would be hard to deny, for on this class of specu- 

 lation the only limitations are those of the ingenuity of the 

 1 " Materials for the Study of Variation." 



