INTRODUCTION 



authorities, verifying, criticizing, combating, rebut- 

 ting, there works a multitude of others who have 

 devoted their lives to the same rich problems, 

 and already every chapter of the bewildering 

 story has found its editors. 



Yet, singular though the omission may seem, no 

 connected outline of this great drama has yet been 

 given us. These researches, preliminary reconnais- 

 sances though they be, are surely worthy of being 

 looked upon as a whole. No one can say that this 

 multitude of observers is not in earnest, nor their 

 work honest, nor their methods competent to the 

 last powers of science. Whatever the uncertainty 

 of the field, it is due to these pioneer minds to 

 treat their labour with respect. What they see in 

 the unexplored land in which they travel belongs 

 to the world. By just such methods, and by just 

 such men, the map of the world of thought is 

 filled in — here from the tracing up of some great 

 river, there from a bearing taken roughly in a 

 darkened sky, yonder from a sudden glint of the 

 sun on a far-off mountain-peak, or by a swift 

 induction of an adventurous mind from a momen- 

 tary glimpse of a natural law. So knowledge 

 grows ; and in a century which has added to the 

 sum of human learning more than all the centuries 

 th^t are past, it is not to be conceived that some 



