PREFACE 



The present work had its origin in an attempt to 

 appreciate the range, the foundation, and the value 

 of evolutionary theories. Such a task entailed a 

 prolonged study, not only of scientific literature, 

 but also of works that belong to neighbouring 

 provinces. 



The information gleaned from these fields had then 

 to be appraised and put together, and an effort made 

 to reduce it into a harmonious system. In doing 

 this the various theories had to be examined with 

 discrimination, enlarged, and built into the structure. 

 It is, therefore, hoped that the reader will meet many 

 new thoughts in the work. 



In the preparatory reading the author had to go 

 through the whole of the relevant literature in various 

 languages. In the book itself he was compelled to 

 restrict himself to what had an essential bearing — 

 either for or against — on the view it presents. 



The work has not been written solely for those 

 who are entirely devoted to the study of science. 

 It appeals to all who take an interest in scientific 

 questions; to all educated people who would inform 



