Preface 



logical and necessary that our education be 

 organised accordingly. 



Such are, in brief, the ideas developed in 

 this book, which give to it also unity. I hope 

 they will obtain the approval of the readers for 

 whom I have intended them, readers who regard 

 with interest the workings of the universe, and 

 who believe that science alone permits of our 

 understanding somewhat of its function. 



XV 



