INTRODUCTORY 29 



S 10. — The Third Claim of Science 



Thus far I have been more particularly examining the 

 influence of science on our treatment of social problems. 

 I have endeavoured to point out that science cannot 

 legitimately be excluded from any field of investigation 

 after truth, and that, further, not only is its method 

 essential to good citizenship, but that its results bear 

 closely on the practical treatment of many social diffi- 

 culties. In this I have endeavoured to justify the state 

 endowment and teaching of pure science as apart from its 

 technical applications. If in this justification I have laid 

 most stress on the advantages of scientific method — on 

 the training which science gives us in the appreciation of 

 evidence, in the classification of facts, and in the elimina- 

 tion of personal bias, in all that may be termed exactness 

 of mind — we must still remember that ultimately the 

 direct influence of pure science on practical life is enor- 

 mous. The observations of Newton on the relation 

 between the motions of a falling stone and the moon, of 

 Galvani on the convulsive movements of frogs' legs in 

 contact with iron and copper, of Darwin on the adaptation 

 of woodpeckers, of tree-frogs, and of seeds to their sur- 

 roundings, of Kirchhoff on certain lines which occur in the 

 spectrum of sunlight, of other investigators on the life- 

 history of bacteria — these and kindred observations have 

 not only revolutionised our conception of the universe, but 

 they have revolutionised, or are revolutionising, our 

 practical life, our means of transit, our social conduct, our 

 treatment of disease. What at the instant of its dis- 

 covery appears to be only a sequence of purely theoretical 

 interest, becomes the basis of discoveries which in the end 

 profoundly modify the conditions of human life. It is 

 impossible to say of any result of pure science that it 

 will not some day be the starting-point of wide-reaching 

 technical applications. The frogs' legs of Galvani and 

 the Atlantic cable seem wide enough apart, but the former 

 was the starting-point of the series of investigations which 

 ended in the latter. In the recent discovery of Hertz 



