xi PREFACE 
their ideals. They who are unfitted will perish as certainly as did 
the dinosaur or the mastodon, regardless of their apparent bigness 
or assumed attractiveness. It will be well with any people which 
undergoes this mental revolution early, and begins first to study 
how it may adjust itself, its moral practices, its social ideals, 
to the hard conditions of universal law. To do so is to prove 
itself to be the superior race or chosen people. To refuse to do 
so is to elect extermination rather than survival, death rather 
than life. 
Dr. Bristol has done a notable service in tracing the develop- 
ment of this concept of social evolution or progress. From the 
formidable list of authorities quoted, and the volume of his quo- 
tations and citations, it is apparent that this topic has received 
large attention from students of social life. This laborious com- 
pilation together with Dr. Bristol’s keen analysis and criticism 
will go far toward making clear a subject which has hitherto 
been obscure. 
T. N. Carver. 
