all other ultimate questions, but shoreless seas whereon 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 mastery. 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 introduction of a new principle, or to
see anything in natural processes that savors of the _ab-extra_. It is
the working 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 explanation that savors of
the theological point of view is equally distasteful to me. I crave and
seek a natural explanation of all phenomena upon this earth, but the
word "natural" to me implies more than mere chemistry and physics. The
birth of a baby, and the blooming of a flower, are natural events, but
the laboratory methods forever fail to give us the key to the secret of
either.

I am forced to conclude that my passion for nature and for all open-air
life, though tinged and stimulated by science, is not a passion for pure