TWO ANSWERS ESSENTIAL xlvii 



provides also the answer to the other, deserves criticism ; 

 but it is irrelevant to criticize the aim of an inquiry 

 because of the mistaken views of the inquirer. 



Every scientific man will agree that careless and 

 slipshod work must be discouraged ; and it will probably 

 be admitted that the study of adaptation, unless under- 

 taken in a spirit of rigid self-criticism, is especially likely 

 to produce an unsatisfactory result. But who is so much 

 interested as the serious student of adaptation in keeping 

 the subject at a high scientific level ? The most notable 

 protest 1 against facile speculation based on Natural 

 Selection that has ever appeared in this country was 

 written by so thorough a Darwinian as Sir William 

 Thiselton-Dyer, and it is hardly necessary to state that 

 it was the work and not the subject that he criticized. 

 The younger men who have devoted themselves to the 

 problems of adaptation under my guidance would be the 

 last to say that they have found the road of investigation 

 a broad and easy one. And, when the necessary pre- 

 cautions are taken, there is no more fruitful study in 

 Biological Science than the one which we owe to the 

 central discovery of Darwin and Wallace. 



9. The Motive Force of Investigation. 



These attempts to disparage one subject and exalt 

 another naturally raise the question, ' Why do we investi- 

 gate at all ? ' It was by curiosity, as I have heard Sir 

 Michael Foster say, that our first parents lost the Garden 

 of Eden; but, in transmitting this same curiosity to 

 their descendants, they gave us a golden bridge by which 

 we may re-enter Paradise. The ultimate justification of 

 all scientific research is, ' I do it because it interests me : 

 I Want to find out.' Any further motive— the well-being 



1 The article Deductive Biology in Nature, vol. xxvii, 1883, pp. 554~5- 



