Preface to the 1922 Edition + 

This book is now reprinted without any alteration whatever, except that a few misprints and grammatical mistakes have been corrected. It is reprinted, because I am still in agreement with its main tendency and conclusions; and it is reprinted without alteration, because I found that, if I were to begin correcting what in it seemed to me to need correction, I could not stop short of rewriting the whole book. + 