PREFACE 



the chief reward of the navigator is the joy of the 

 adventure? 



Sir Thomas Browne said, over two hundred years 

 ago, that in philosophy truth seemed double-faced, 

 by which I fancy he meant that there was always 

 more than one point of view of all great problems, 

 often contradictory points of view, from which truth 

 is revealed. In the following pages I am aware that 

 two ideas, or principles, struggle in my mind for mas- 

 tery. One is the idea of the super-mechanical and the 

 super-chemical character of living things; the other 

 is the idea of the supremacy and universality of what 

 we call natural law. The first probably springs from 

 my inborn idealism and literary habit of mind; the 

 second from my love of nature and my scientific 

 bent. It is hard for me to reduce the life impulse to 

 a level with common material forces that shape and 

 control the world of inert matter, and it is equally 

 hard for me to reconcile my reason to the introduc- 

 tion of a new principle, or to see anything in natural 

 processes that savors of the ab-extra. It is the work- 

 ing of these two different ideas in my mind that 

 seems to give rise to the obvious contradictions that 

 crop out here and there throughout this volume. 

 An explanation of life phenomena that savors of the 

 laboratory and chemism repels me, and an explan- 

 ation that savors of the theological point of view is 

 equally distasteful to me. I crave and seek a natu- 

 ral explanation of all phenomena upon this earth, 



vi 



