56 INTRODUCTION. 



alone constitute the mental life which interests us. Only 

 so far as we have taken part in building the scaffolding, 

 only in so far as we have witnessed the many contrivances 

 which have been used, only in so far as we have seen the 

 growth of any structure from small beginnings, from the 

 first sketch of the architect, can we say that we know 

 something of the mental life which lies hidden in and 

 behind those external signs and documents. A closer 

 study of what we ourselves have witnessed is thus the 

 only way of attaining some insight into the workings of 

 the mind the spiritual life of mankind. We shall pres- 

 r ently find that in science as well as in philosophy every 

 period starts from certain assumptions and proceeds ac- 



31. cording to certain methods, that certain habits of thought 

 the most become general, and certain views become accepted ; but in 



approved, 



da ve and ir ^ e course ^ one or ^ wo generations we find those assump- 

 be - tions questioned, those methods criticised, a new habit of 

 thought introduced, and those general views which seemed 

 so natural and convenient giving way to new and altered 

 ones. The whole fabric of society, the whole structure of 

 science and knowledge, all the applications of art, have to 

 be remodelled on new principles, and to meet our changed 



32. demands. Few indeed, very few, of the old creations 



One century 



does not remain. One or two so-called laws of science that sur- 



inhent all 



i^di^awui v i ye ' a ^ ew dozen books that are re-edited, half-a-dozen 

 works of art and one or two great poems, this is about 

 all that our century will at ibs close have preserved as the 

 living inheritance of its early years : all the others will be 

 relegated to the growing bulk of historical records. Pos- 

 sessed of merely monumental interest as documents of a 

 bygone life, these creations had to be left aside as incap- 



