llowing 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
science, but for literature and philosophy. My imagination and ingrained
humanism are appealed to by the facts and methods of natural history. I
find something akin to poetry and religion (using the latter word in its
non-mythological sense, as indicating the sum of mystery and reverence
we feel in the presence of the great facts of life and death) in the
shows of day and night, and in my excursions to fields and woods. The
love of nature is a different thing from the love of science, though the
two may go together. The Wordsworthian sense in nature, of "something
far more deeply interfused" than the principles of exact science, is
probably the source of nearly if not quite all that this volume holds.
To the rigid man of science this is frank mysticism; but without a sense
of the unknown and unknowable, life is flat and barren. Without the
emotion of the beautiful, the sublime, the mysterious, there is no art,
no religion, no literature. How to get from th