MOTIVE OF SCIENTIFIC DISCOVERY 295 



often do their utmost to develop them, merely for Book iv 

 the sake of the pleasure which the exercise of these 

 powers brings with it ; whilst literature is even more 

 obviously than painting cultivated by men who 

 devote themselves to it solely as a means of self- 

 expression. Indeed, it might reasonably be contended 

 that finer books and paintings would be produced if 

 it were impossible for painters and writers to make 

 money by producing them, than are now produced 

 with a view to captivating the public purchaser. 



So, too, the pursuit of scientific and philosophic and also to 

 truth arduous though it is is generally under- 

 taken by men whose principal motive is the pleasure 

 their work brings them. 



A watcher of the skies, 

 When some new planet swims into his ken, 



may well be supposed to find in that thrilling 

 moment a reward sufficient to compensate him for 

 all his pains in arriving at it ; and most branches of 

 science would yield us similar illustrations. Indeed, 

 the career characteristic of scientists and philoso- 

 phers generally is a conclusive proof that the 

 principal motive of their activity is not the desire 

 of any extrinsic reward, the amount of which they 

 will balance against the amount or the quality of 

 their efforts, but a passion for truth as truth, which 

 they indulge in for its own sake only. 



Now granting all this, what will its bearing be 

 on the question of whether the pleasures of pure 

 self-realisation will suffice to stimulate those ex- 



