All living bodies, when life leaves them, go back to the earth from whence they came. What was it in the first instance that gathered their elements from the earth and built them up into such wonderful mechanisms? If we say it was nature, do we mean by nature a physical force or an immaterial principle? Did the earth itself bring forth a man, or did something breathe upon the inert clay till it became a living spirit?

As life is a physical phenomenon, appearing in a concrete physical world, it is, to that extent, within the domain of physical science, and appeals to the scientific mind. Physical science is at home only in the experimental, the verifiable. Its domain ends where that of philosophy begins.

The question of how life arose in a universe of dead matter is just as baffling a question to the ordinary mind, as how the universe itself arose. If we assume that the germs of life drifted to us from other spheres, propelled by the rays of the sun, or some other celestial agency, as certain modern scientific philosophers have assumed, we have only removed the mystery farther away from us. If we assume that it came by spontaneous generation, as Haeckel and others assume, then we are only cutting a knot which we cannot untie. The god of spontaneous generation is as miraculous as any other god. We cannot break the causal sequence without a miracle. If something came from nothing, then there is not only the end of the problem, but also the end of our boasted science.

Science is at home in discussing all the material manifestations of life—the parts played by colloids and ferments, by fluids and gases, and all the organic compounds, and by mechanical and chemical principles; it may analyze and tabulate all life processes, and show the living body as a most wonderful and complex piece of mechanism, but before the question of the origin of life itself it stands dumb, and, when speaking through such a man as Tyndall, it also stands humble and reverent. After Tyndall had, to his own satisfaction, reduced all like phenomena to mechanical attraction and repulsion, he stood with uncovered head before what he called the "mystery and miracle of vitality." The mystery and miracle lie in the fact that in the organic world the same elements combine with results so different from those of the inorganic world. Something seems to have inspired them with a new purpose. In the inorganic world, the primary elements go their ceaseless round from compound to compound, from solid to fluid or gaseous, and back again, forming the world of inert matter as we know it, but in the organic world the same elements form thousands of new combinations unknown to them before, and thus give rise to the myriad forms of life that inhabit the earth.

The much-debated life question has lately found an interesting exponent in Professor Benjamin Moore, of the University of Liverpool. His volume on the subject in the "Home University Library" is very readable, and, in many respects, convincing. At least, so far as it is the word of exact science on the subject it is convincing; so far as it is speculative, or philosophical, it is or is not convincing, according to the type of mind of the reader. Professor Moore is not a bald mechanist or materialist like Professor Loeb, or Ernst Haeckel, nor is he an idealist or spiritualist, like Henri Bergson or Sir Oliver Lodge. He may be called a scientific vitalist. He keeps close to lines of scientific research as these lines lead him through the maze of the primordial elements of matter, from electron to atom, from atom to molecule, from molecule to colloid, and so up to the border of the living world. His analysis of the processes of molecular physics as they appear in the organism leads him to recognize and to name a new force, or a new manifestation of force, which he hesitates to call vital, because of the associations of this term with a prescientific age, but which he calls "biotic energy."

Biotic energy is peculiar to living bodies, and "there are precisely the same criteria for its existence," says Professor Moore, "as for the existence of any one of the inorganic energy types, viz., a set of discrete phenomena; and its nature is as mysterious to us as the cause of any one of these inorganic forms about which also we know so little. "It is biotic energy which guides the development of the ovum, which regulates the exchanges of the cell, and causes such phenomena as nerve impulse, muscular contraction, and gland secretion, and it is a form of energy which arises in colloidal structures, just as magnetism appears in iron, or radio-activity in uranium or radium, and in its manifestations it undergoes exchanges with other forms of energy, in the same manner as these do among one another."

Like Professor Henderson, Professor Moore concedes to the vitalists about all they claim—namely, that there is some form of force or manifestation of energy peculiar to living bodies, and one that cannot be adequately described in terms of physics and chemistry. Professor Moore says this biotic energy "arises in colloidal structures," and so far as biochemistry can make out, arises spontaneously and gives rise to that marvelous bit of mechanism, the cell. In the cell appears "a form of energy unknown outside life processes which leads the mazy dance of life from point to point, each new development furnishing a starting point for the next one." It not only leads the dance along our own line of descent from our remote ancestors—it leads the dance along the long road of evolution from the first unicellular form in the dim palÆozoic seas to the complex and highly specialized forms of our own day.

The secret of this life force, or biotic energy, according to Professor Moore, is in the keeping of matter itself. The steps or stages from the depths of matter by which life arose, lead up from that imaginary something, the electron, to the inorganic colloids, or to the crystallo-colloids, which are the threshold of life, each stage showing some new transformation of energy. There must be an all-potent energy transformation before we can get chemical energy out of physical energy, and then biotic energy out of chemical energy. This transformation of inorganic energy into life energy cannot be traced or repeated in the laboratory, yet science believes the secret will sometime be in its hands. It is here that the materialistic philosophers, such as Professors Moore and Loeb, differ from the spiritualistic philosophers, such as Bergson, Sir Oliver Lodge, Professor Thompson, and others.

Professor Moore has no sympathy with those narrow mechanistic views that see in the life processes "no problems save those of chemistry and physics." "Each link in the living chain may be physico-chemical, but the chain as a whole, and its purpose, is something else." He draws an analogy from the production of music in which purely physical factors are concerned; the laws of harmonics account for all; but back of all is something that is not mechanical and chemical—there is the mind of the composer, and the performers, and the auditors, and something that takes cognizance of the whole effect. A complete human philosophy cannot be built upon physical science alone. He thinks the evolution of life from inert matter is of the same type as the evolution of one form of matter from another, or the evolution of one form of energy from another—a mystery, to be sure, but little more startling in the one case than in the other. "The fundamental mystery lies in the existence of those entities, or things, which we call matter and energy," out of the play and interaction of which all life phenomena have arisen. Organic evolution is a series of energy exchanges and transformations from lower to higher, but science is powerless to go behind the phenomena presented and name or verify the underlying mystery. Only philosophy can do this. And Professor Moore turns philosopher when he says there is beauty and design in it all, "and an eternal purpose which is ever progressing."

Bergson sets forth his views of evolution in terms of literature and philosophy. Professor Moore embodies similar views in his volume, set forth in terms of molecular science. Both make evolution a creative and a continuous process. Bergson lays the emphasis upon the cosmic spirit interacting with matter. Professor Moore lays the emphasis upon the indwelling potencies of matter itself (probably the same spirit conceived of in different terms). Professor Moore philosophizes as truly as does Bergson when he says "there must exist a whole world of living creatures which the microscope has never shown us, leading up to the bacteria and the protozoa. The brink of life lies not at the production of protozoa and bacteria, which are highly developed inhabitants of our world, but away down among the colloids; and the beginning of life was not a fortuitous event occurring millions of years ago and never again repeated, but one which in its primordial stages keeps on repeating itself all the time in our generation. So that if all intelligent creatures were by some holocaust destroyed, up out of the depths in process of millions of years, intelligent beings would once more emerge." This passage shows what a speculative leap or flight the scientific mind is at times compelled to take when it ventures beyond the bounds of positive methods. It is good philosophy, I hope, but we cannot call it science. Thrilled with cosmic emotion, Walt Whitman made a similar daring assertion:—

II

Evolution is creative, whether it works in matter—as Bergson describes, or whether its path lies up through electrons and atoms and molecules, as Professor Moore describes. There is something that creates and makes matter plastic to its will. Whether we call matter "the living garment of God," as Goethe did, or a reservoir of creative energy, as Tyndall and his school did, and as Professor Moore still does, we are paying homage to a power that is super-material. Life came to our earth, says Professor Moore, through a "well-regulated orderly development," and it "comes to every mother earth of the universe in the maturity of her creation when the conditions arrive within suitable limits." That no intelligent beings appeared upon the earth for millions upon millions of years, that for whole geologic ages there was no creature with more brains than a snail possesses, shows the almost infinitely slow progress of development, and that there has been no arbitrary or high-handed exercise of creative power. The universe is not run on principles of modern business efficiency, and man is at the head of living forms, not by the fiat of some omnipotent power, some superman, but as the result of the operation of forces that balk at no delay, or waste, or failure, and that are dependent upon the infinitely slow ripening and amelioration of both cosmic and terrestrial conditions.

We do not get rid of God by any such dictum, but we get rid of the anthropomorphic views which we have so long been wont to read into the processes of nature. We dehumanize the universe, but we do not render it the less grand and mysterious. Professor Moore points out to us how life came to a cooling planet as soon as the temperature became low enough for certain chemical combinations to appear. There must first be oxides and saline compounds, there must be carbonates of calcium and magnesium, and the like. As the temperature falls, more and more complex compounds, such as life requires, appear; till, in due time, carbon dioxide and water are at hand, and life can make a start. At the white heat of some of the fixed stars, the primary chemical elements are not yet evolved; but more and more elements appear, and more and more complex compounds are formed as the cooling process progresses.

"This note cannot be too strongly sounded, that as matter is allowed capacity for assuming complex forms, those complex forms appear. As soon as oxides can be there, oxides appear; when temperature admits of carbonates, then carbonates are forthwith formed. These are experiments which any chemist can to-day repeat in a crucible. And on a cooling planet, as soon as temperature will admit the presence of life, then life appears, as the evidence of geology shows us." When we speak of the beginning of life, it is not clear just what we mean. The unit of all organized bodies is the cell, but the cell is itself an organized body, and must have organic matter to feed upon. Hence the cell is only a more complex form of more primitive living matter. As we go down the scale toward the inorganic, can we find the point where the living and the non-living meet and become one? "Life had to surge a long way up from the depths before a green plant cell came into being." When the green plant cell was found, life was fairly launched. This plant cell, in the form of chlorophyll, by the aid of water and the trace of carbon dioxide in the air, began to store up the solar energy in fruit and grain and woody tissue, and thus furnish power to run all forms of life machinery.

The materialists or naturalists are right in urging that we live in a much more wonderful universe than we have ever imagined, and that in matter itself sleep potencies and possibilities not dreamt of in our philosophy. The world of complex though invisible activities which science reveals all about us, the solar and stellar energies raining upon us from above, the terrestrial energies and influences playing through us from below, the transformations and transmutations taking place on every hand, the terrible alertness and potency of the world of inert matter as revealed by a flash of lightning, the mysteries of chemical affinity, of magnetism, of radio-activity, all point to deep beneath deep in matter itself. It is little wonder that men who dwell habitually upon these things and are saturated with the spirit and traditions of laboratory investigation, should believe that in some way matter itself holds the mystery of the origin of life. On the other hand, a different type of mind, the more imaginative, artistic, and religious type, recoils from the materialistic view.

The sun is the source of all terrestrial energy, but the different forms that energy takes—in the plant, in the animal, in the brain of man—this type of mind is bound to ask questions about that. Gravity pulls matter down; life lifts it up; chemical forces pull it to pieces; vital forces draw it together and organize it; the winds and the waters dissolve and scatter it; vegetation recaptures and integrates it and gives it new qualities. At every turn, minds like that of Sir Oliver Lodge are compelled to think of life as a principle or force doing something with matter. The physico-chemical forces will not do in the hands of man what they do in the hands of Nature. Such minds, therefore, feel justified in thinking that something which we call "the hands of Nature," plays a part—some principle or force which the hands of man do not hold.