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 zesthetic 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 :! “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.” 
