Preface 



shall therefore begin by first attacking the more complex 

 facts, these being really the only important ones; putting 

 aside for the moment the mere trivialities of elementary 

 and simple facts, which, in the sequel, will explain 

 themselves. 



Instead of plodding through this dust of elementary 

 facts which by beclouding our ascent, retard it, we 

 shall advance to the heights, from whence, after a wide 

 view over the whole accessible area, we may descend 

 at leisure to explore local particulars. 



The present work falls naturally irito two principal 

 parts : 



Book I. is a critical study of the classical theories 

 relating to evolution, to physiological individuality, to 

 psychological individuality, and to the principal evolu- 

 tionary philosophies, and at the same time it is a forecast 

 of the essential inductions of Book II. 



Book II. is the actual statement of our scientific 

 philosophy. 



