28 



INTRODUCTION. 



by the more delightful venture of filling up the dim out- 

 lines which we see before us, with analogies of past ex- 

 perience or creations of our imagination. And even if 

 we do descend into the plains and continue the minuter 

 and more laborious search, we cannot rid ourselves of cer- 

 tain preconceived but frequently misleading ideas which 

 the superficial glance has impressed on our minds. 



The condensation may become an idealisation of know- 

 ledge. History affords numerous examples of these dif- 

 ferent stages of progress ; centuries of dull accumulation, 

 of unmethodical and ill-arranged learning, have been fol- 

 lowed by short periods of enlightenment, by the trium- 

 phant shout of sudden discovery or the confident hope of 

 invention. Patient work and real progress have for a long 

 time been repressed by the allurements of seductive phan- 

 toms, which have had to be abandoned after an immense 

 waste of labour. New prospects have suddenly opened 

 the view into vast unexplored regions, heights have been 

 gained from which the whole of human knowledge ap- 

 peared for the moment condensed into a single truth or 

 idealised into a vision, and again these delightful achieve- 

 ments have for a time appeared lost in an all-pervading 

 discouragement and dismay. 



Whether our century has been characterised by any 



J 



one or by a succession of several of these varying moods, 

 is a question which I hope to answer in the sequel. For 

 the present it is sufficient to note that in both directions 

 3 in that of accumulating and in that of condensing and 

 TOnt e ^- n un- idealising knowledge the efforts of the nineteenth cen- 

 ueamnia- tury have been many and conspicuous. In the former it 



tion of . 



knowledge, is altogether unparalleled, whereas in the latter it has 



2. 



Object of 



the book. 



