PREFACE 



NINE of the essays that follow have been 

 written especially for this book. The au- 

 thors are: Kirtley F. Mather, professor of 

 Geology, Harvard University; Heber D. Curtis, di- 

 rector of the Detroit Observatory of the University of 

 Michigan; Edwin G. Conklin, professor of Zoology, 

 Princeton University; George Thomas White Patrick, 

 professor of Philosophy, the University of Iowa; Wil- 

 liam McDougall, professor of Psychology, Duke Uni- 

 versity; Sir J. Arthur Thomson, author of "The Out- 

 line of Science," etc.; Harlan T. Stetson, director of 

 the Perkins Observatory, Ohio Wesleyan University; 

 Sir Oliver Lodge, author of "Why I Believe in Per- 

 sonal Immortality," etc.; and Dr. J. Malcolm Bird, 

 formerly research officer for the American Society for 

 Psychical Research and author of "Einstein's Theories 

 of Relativity and Gravitation." 



The other seven chapters have been selected from 

 available sources and made to conform to the theme 

 of the volume. In each Instance credit has been given. 



The contributors were asked to write with entire 

 freedom, seeking only to serve truth and human good; 

 and appreciation Is here expressed for their work, 

 much of which was done in the midst of pressing re- 

 sponsibilities, and In the interests of a greater cause. 



Also thanks are due to Dr. Thomas H. Billings and 

 Dr. Arthur D. Little for critical examination of my 



