As life nears its end with me, I find myself meditating more and more upon the mystery of its nature and origin, yet without the least hope that I can find out the ways of the Eternal in this or in any other world. In these studies I fancy I am about as far from mastering the mystery as the ant which I saw this morning industriously exploring a small section of the garden walk is from getting a clear idea of the geography of the North American Continent. But the ant was occupied and was apparently happy, and she must have learned something about a small fraction of that part of the earth's surface.

I have passed many pleasant summer days in my hay-barn study, or under the apple trees, exploring these questions, and though I have not solved them, I am satisfied with the clearer view I have given myself of the mystery that envelops them. I have set down in these pages all the thoughts that have come to me on this subject. I have not aimed so much at consistency as at clearness and definiteness of statement, letting my mind drift as upon a shoreless sea. Indeed, what are such questions, and 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 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 the clod underfoot to the brain and consciousness of man without invoking something outside of, and superior to, natural laws, is the question. For my own part I content myself with the thought of some unknown and doubtless unknowable tendency or power in the elements themselves—a kind of universal mind pervading living matter and the reason of its living, through which the whole drama of evolution is brought about.

This is getting very near to the old teleological conception, as it is also near to that of Henri Bergson and Sir Oliver Lodge. Our minds easily slide into the groove of supernaturalism and spiritualism because they have long moved therein. We have the words and they mould our thoughts. But science is fast teaching us that the universe is complete in itself; that whatever takes place in matter is by virtue of the force of matter; that it does not defer to or borrow from some other universe; that there is deep beneath deep in it; that gross matter has its interior in the molecule, and the molecule has its interior in the atom, and the atom has its interior in the electron, and that the electron is matter in its fourth or non-material state—the point where it touches the super-material. The transformation of physical energy into vital, and of vital into mental, doubtless takes place in this invisible inner world of atoms and electrons. The electric constitution of matter is a deduction of physics. It seems in some degree to bridge over the chasm between what we call the material and the spiritual. If we are not within hailing distance of life and mind, we seem assuredly on the road thither. The mystery of the transformation of the ethereal, imponderable forces into the vital and the mental seems quite beyond the power of the mind to solve. The explanation of it in the bald terms of chemistry and physics can never satisfy a mind with a trace of idealism in it.

The greater number of the chapters of this volume are variations upon a single theme,—what Tyndall called "the mystery and the miracle of vitality,"—and I can only hope that the variations are of sufficient interest to justify the inevitable repetitions which occur. I am no more inclined than Tyndall was to believe in miracles unless we name everything a miracle, while at the same time I am deeply impressed with the inadequacy of all known material forces to account for the phenomena of living things.

That word of evil repute, materialism, is no longer the black sheep in the flock that it was before the advent of modern transcendental physics. The spiritualized materialism of men like Huxley and Tyndall need not trouble us. It springs from the new conception of matter. It stands on the threshold of idealism or mysticism with the door ajar. After Tyndall had cast out the term "vital force," and reduced all visible phenomena of life to mechanical attraction and repulsion, after he had exhausted physics, and reached its very rim, a mighty mystery still hovered beyond him. He recognized that he had made no step toward its solution, and was forced to confess with the philosophers of all ages that