It should not surprise nor disturb us that the scientific interpretation of life leads to materialism, or to the conviction of the all-sufficiency of the mechanical and chemical forces of dead matter to account for all living phenomena. It need not surprise us because positive science, as such, can deal only with physical and chemical forces. If there is anything in this universe besides physical and chemical force, science does not know it. It does not know it because it is absolutely beyond the reach of its analysis. When we go beyond the sphere of the concrete, the experimental, the verifiable, only our philosophy can help us. The world within us, the world of psychic forces, is beyond the ken of science. It can analyze the living body, trace all its vital processes, resolve them into their mechanical and chemical equivalents, show us the parts played by the primary elements, the part played by the enzymes, or ferments, and the like, and yet it cannot tell us the secret of life—of that which makes organic chemistry so vastly different from inorganic.It discloses to us the wonders of the cell—a world of mystery by itself; it analyzes the animal body into organs, and the organs into tissues, and the tissues into cells, but the secret of organization utterly baffles it. After Professor Wilson had concluded his masterly work on the cell, he was forced to admit that the final mystery of the cell eluded him, and that his investigation "on the whole seemed to widen rather than to narrow the enormous gap that separates even the lowest forms of life from the inorganic world."
All there is outside the sphere of physical science belongs to religion, to philosophy, to art, to literature. Huxley spoke strictly and honestly as a man of science, when he related consciousness to the body, as the sound of a clock when it strikes is related to the machinery of the clock. The scientific analysis of a living body reveals nothing but the action of the mechanical and chemical principles. If you analyze it by fire or by cremation, you get gases and vapors and mineral ash, that is all; the main thing about the live body—its organization, its life—you do not get. Of course science knows this; and to account for this missing something, it philosophizes, and relegates it to the interior world of molecular physics—it is all in the way the ultimate particles of matter were joined or compounded, were held together in the bonds of molecular matrimony. What factor or agent or intelligence is activeor directive in this molecular marriage of the atoms, science does not inquire. Only philosophy can deal with that problem.
What can science see or find in the brain of man that answers to the soul? Only certain movements of matter in the brain cortex. What difference does it find between inert matter and a living organism? Only a vastly more complex mechanics and chemistry in the latter. A wide difference, not of kind, but of degree. The something we call vitality, that a child recognizes, science does not find; vitality is somethingsui generis. Scientific analysis cannot show us the difference between the germ cell of a starfish and the germ cell of a man; and yet think of what a world of difference is hidden in those microscopic germs! What force is there in inert matter that can build a machine by the adjustment of parts to each other? We can explain the most complex chemical compounds by the action of chemical forces and chemical affinity, but they cannot explain that adjustment of parts to each other, the coördination of their activities that makes a living machine.
In organized matter there is something that organizes. "The cell itself is an organization of smaller units," and to drive or follow the organizing principle into the last hiding-place is past the power of biological chemistry. What constitutes the guiding force or principle of a living body, adjusting all its parts, making them pull together, making of thecirculation one system in which the heart, the veins, the arteries, the lungs, all work to one common end, coördinating several different organs into a digestive system, and other parts into the nervous system, is a mystery that no objective analysis of the body can disclose.
To refer vitality to complexity alone, is to dodge the question. Multiplying the complexity of a machine, say of a watch, any conceivable number of times would not make it any the less a machine, or change it from the automatic order to the vital order. A motor-car is a vastly more complex mechanism than a wheelbarrow, and yet it is not the less a machine. On the other hand, an amœba is a far simpler animal than a man, and yet it is just as truly living. To refer life to complexity does not help us; we want to know what lies back of the complexity—what makes it a new species of complexity.
We cannot explain the origin of living matter by the properties which living matter possesses. There are three things that mechanics and chemistry cannot explain: the relation of the psychical to the physical through the law of the conservation and correlation of forces; the agent or principle that guides the blind chemical and physical forces so as to produce the living body; and the kind of forces that have contributed to the origin of that morphological unit—the cell.
A Western university professor in a recent essay sounds quite a different note on this subject from the one that comes to us from Harvard. Says Professor Otto C. Glaser, of the University of Michigan, in a recent issue of the "Popular Science Monthly": "Does not the fitness of living things; the fact that they perform acts useful to themselves in an environment which is constantly shifting, and often very harsh; the fact that in general everything during development, during digestion, during any of the complicated chains of processes which we find, happens at the right time, in the right place, and to the proper extent; does not all this force us to believe that there is involved something more than mere chemistry and physics?—something, not consciousness necessarily, yet its analogue—a vitalx?"
There is this suggestive fact about these recent biological experiments of Dr. Carrel, of the Rockefeller Institute: they seem to prove that the life of a man is not merely the sum of the life of the myriad cells of his body. Stab the man to death, and the cells of his body still live and will continue to live if grafted upon another live man. Probably every part of the body would continue to live and grow indefinitely, in the proper medium. That the cell life should continue after the soul life has ceased is very significant. It seems a legitimate inference from this fact that the human body is the organ or instrument of some agent that is not of the body.The functional or physiological life of the body as a whole, also seems quite independent of our conscious volitional or psychic life. That which repairs and renews the body, heals its wounds, controls and coordinates its parts, adapts it to its environment, carries on its processes during sleep, in fact in all our involuntary life, seems quite independent of the man himself. Is the spirit of a race or a nation, or of the times in which we live, another illustration of the same mysterious entity?
If the vital principle, or vital force, is a fiction, invented to give the mind something to take hold of, we are in no worse case than we are in some other matters. Science tells us that there is no suchthingas heat, or light; these are only modes of activity in matter.
In the same way we seem forced to think of life, vitality, as an entity—a fact as real as electricity or light, though it may be only a mode of motion. It may be of physico-chemical origin, as much so as heat, or light; and yet it is something as distinctive as they are among material things, and is involved in the same mystery. Is magnetism or gravitation a real thing? or, in the moral world, is love, charity, or consciousness itself? The world seems to be run by nonentities. Heat, light, life, seem nonentities. That which organizes the different parts or organs of the human body into a unit, and makes of the many organs one organism, is a nonentity. Thatwhich makes an oak an oak, and a pine a pine, is a nonentity. That which makes a sheep a sheep, and an ox an ox, is to science a nonentity. To physical science the soul is a nonentity.
There is something in the cells of the muscles that makes them contract, and in the cells of the heart that makes it beat; that something is not active in the other cells of the body. But it is a nonentity. The body is a machine and a laboratory combined, but that which coördinates them and makes them work together—what is that? Another nonentity. That which distinguishes a living machine from a dead machine, science has no name for, except molecular attraction and repulsion, and these are names merely; they are nonentities. Is there not molecular attraction and repulsion in a steam-engine also? And yet it is not alive. What has to supplement the mechanical and the chemical to make matter alive? We have no name for it but the vital, be it an entity or a nonentity. We have no name for a flash of lightning but electricity, be it an entity or a nonentity. We have no name for that which distinguishes a man from a brute, but mind, soul, be it an entity or a nonentity. We have no name for that which distinguishes the organic from the inorganic but vitality, be it an entity or a nonentity.
Without metaphysics we can do nothing; without mental concepts, where are we? Natural selection is as much a metaphysical phrase as is consciousness, or the subjective and the objective. Natural selection is not an entity, it is a name for what we conceive of as a process. It is natural rejection as well. The vital principle is a metaphysical concept; so is instinct; so is reason; so is the soul; so is God.
Many of our concepts have been wrong. The concept of witches, of disease as the work of evil spirits, of famine and pestilence as the visitation of the wrath of God, and the like, were unfounded. Science sets us right about all such matters. It corrects our philosophy, but it cannot dispense with the philosophical attitude of mind. The philosophical must supplement the experimental.
In fact, in considering this question of life, it is about as difficult for the unscientific mind to get along without postulating a vital principle or force—which, Huxley says, is analogous to the idea of a principle of aquosity in water—as it is to walk upon the air, or to hang one's coat upon a sunbeam. It seems as if something must breathe upon the dead matter, as at the first, to make it live. Yet if there is a distinct vital force it must be correlated with physical force, it must be related causally to the rest. The idea of a vital force as something newand distinct and injected into matter from without at a given time and place in the earth's history, must undoubtedly be given up. Instead of escaping from mechanism, this notion surrenders one into the hands of mechanism, since to supplement or reinforce a principle with some other principle from without, is strictly a mechanical procedure. But the conception of vitality as potential in matter, or of the whole universe as permeated with spirit, which to me is the same thing, is a conception that takes life out of the categories of the fortuitous and the automatic.
No doubt but that all things in the material world are causally related, no doubt of the constancy of matter and force, no doubt but that all phenomena are the result of natural principles, no doubt that the living arose from the non-living, no doubt that the evolution process was inherent in the constitution of the world; and yet there is a mystery about it all that is insoluble. The miracle of vitality takes place behind a veil that we cannot penetrate, in the inmost sanctuary of the molecules of matter, in that invisible, imaginary world on the borderland between the material and the immaterial. We may fancy that it is here that the psychical effects its entrance into the physical—that spirit weds matter—that the creative energy kindles the spark we call vitality. At any rate, vitality evidently begins in that inner world of atoms and molecules; butwhether as the result of their peculiar and very complex compounding or as the cause of the compounding—how are we ever to know? Is it not just as scientific to postulate a new principle, the principle of vitality, as to postulate a new process, or a new behavior of an old principle? In either case, we are in the world of the unverifiable; we take a step in the dark. Most of us, I fancy, will sympathize with George Eliot, who says in one of her letters: "To me the Development Theory, and all other explanations of processes by which things came to be, produce a feeble impression compared with the mystery that lies under the processes."
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 weassume 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 theworld 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, arisesspontaneouslyand 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 notonly 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 analogyfrom 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 theemphasis 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:—
"There is no stoppage, and never can be stoppage,If I, you, and the worlds, and all beneath or upon their surfaces,were this moment reduced back to a pallid float, it wouldnot avail in the long run,We should surely bring up again where we now stand,And surely go as much farther, and then farther and farther."
"There is no stoppage, and never can be stoppage,If I, you, and the worlds, and all beneath or upon their surfaces,were this moment reduced back to a pallid float, it wouldnot avail in the long run,We should surely bring up again where we now stand,And surely go as much farther, and then farther and farther."
"There is no stoppage, and never can be stoppage,
If I, you, and the worlds, and all beneath or upon their surfaces,
were this moment reduced back to a pallid float, it would
not avail in the long run,
We should surely bring up again where we now stand,
And surely go as much farther, and then farther and farther."
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 coolingplanet, 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 inertmatter 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.
There is one phase of the much-discussed question of the nature and origin of life which, so far as I know, has not been considered either by those who hold a brief for the physico-chemical view or by those who stand for some form of vitalism or idealism. I refer to the small part that life plays in the total scheme of things. The great cosmic machine would go on just as well without it. Its relation to the whole appears to be little different from that of a man to the train in which he journeys. Life rides on the mechanical and chemical forces, but it does not seem to be a part of them, nor identical with them, because they were before it, and will continue after it is gone.
The everlasting, all-inclusive thing in this universe seems to be inert matter with the energy it holds; while the slight, flitting, casual thing seems to be living matter. The inorganic is from all eternity to all eternity; it is distributed throughout all space and endures through all time, while the organic is, in comparison, only of the here and thenow; it was not here yesterday, and it may not be here to-morrow; it comes and goes. Life is like a bird of passage which alights and tarries for a time and is gone, and the places where it perched and nested and led forth its brood know it no more. Apparently it flits from world to world as the great cosmic spring comes to each, and departs as the cosmic winter returns to each. It is a visitor, a migrant, a frail, timid thing, which waits upon the seasons and flees from the coming tempests and vicissitudes.
How casual, uncertain, and inconsequential the vital order seems in our own solar system—a mere incident or by-product in its cosmic evolution! Astronomy sounds the depths of space, and sees only mechanical and chemical forces at work there. It is almost certain that only a small fraction of the planetary surfaces is the abode of life. On the earth alone, of all the great family of planets and satellites, is the vital order in full career. It may yet linger upon Mars, but it is evidently waning. On the inferior planets it probably had its day long ago, while it must be millions of years before it comes to the superior planets, if it ever comes to them. What a vast, inconceivable outlay of time and energy for such small returns! Evidently the vital order is only an episode, a transient or secondary phase of matter in the process of sidereal evolution. Astronomic space is strewn with dead worlds, as a NewEngland field is with drift boulders. That life has touched and tarried here and there upon them can hardly be doubted, but if it is anything more than a passing incident, an infant crying in the night, a flush of color upon the cheek, a flower blooming by the wayside, appearances are against it.
We read our astronomy and geology in the light of our enormous egotism, and appropriate all to ourselves; but science sees in our appearance here a no more significant event than in the foam and bubbles that whirl and dance for a moment upon the river's current. The bubbles have their reason for being; all the mysteries of molecular attraction and repulsion may be involved in their production; without the solar energy, and the revolution of the earth upon its axis, they would not appear; and yet they are only bubbles upon the river's current, as we are bubbles upon the stream of energy that flows through the universe. Apparently the cosmic game is played for us no more than for the parasites that infest our bodies, or for the frost ferns that form upon our window-panes in winter. The making of suns and systems goes on in the depths of space, and doubtless will go on to all eternity, without any more reference to the vital order than to the chemical compounds.
The amount of living matter in the universe, so far as we can penetrate it, compared with the non-living, is, in amount, like a flurry of snow thatwhitens the fields and hills of a spring morning compared to the miles of rock and soil beneath it; and with reference to geologic time it is about as fleeting. In the vast welter of suns and systems in the heavens above us, we see only dead matter, and most of it is in a condition of glowing metallic vapor. There are doubtless living organisms upon some of the invisible planetary bodies, but they are probably as fugitive and temporary as upon our own world. Much of the surface of the earth is clothed in a light vestment of life, which, back in geologic time, seems to have more completely enveloped it than at present, as both the arctic and the antarctic regions bear evidence in their coal-beds and other fossil remains of luxuriant vegetable growths.
Strip the earth of its thin pellicle of soil, thinner with reference to the mass than is the peel to the apple, and you have stripped it of its life. Or, rob it of its watery vapor and the carbon dioxide in the air, both stages in its evolution, and you have a dead world. The huge globe swings through space only as a mass of insensate rock. So limited and evanescent is the world of living matter, so vast and enduring is the world of the non-living. Looked at in this way, in the light of physical science, life, I repeat, seems like a mere passing phase of the cosmic evolution, a flitting and temporary stage of matter which it passes through in the procession of changes on the surface of a cooling planet. Between the fiery mist of thenebula, and the frigid and consolidated globe, there is a brief span, ranging over about one hundred and twenty degrees of temperature, where life appears and organic evolution takes place. Compared with the whole scale of temperature, from absolute zero to the white heat of the hottest stars, it is about a hand's-breadth compared to a mile.
Life processes cease, but chemical and mechanical processes go on forever. Life is as fugitive and uncertain as the bow in the clouds, and, like the bow in the clouds, is confined to a limited range of conditions. Like the bow, also, it is a perpetual creation, a constant becoming, and its source is not in the matter through which it is manifested, though inseparable from it. The material substance of life, like the rain-drops, is in perpetual flux and change; it hangs always on the verge of dissolution and vanishes when the material conditions fail, to be renewed again when they return. We know, do we not? that life is as literally dependent upon the sun as is the rainbow, and equally dependent upon the material elements; but whether the physical conditions sum up the whole truth about it, as they do with the bow, is the insoluble question. Science says "Yes," but our philosophy and our religion say "No." The poets and the prophets say "No," and our hopes and aspirations say "No."
Where, then, shall we look for the key to this mysterious thing we call life? Modern biochemistry will not listen to the old notion of a vital force—that is only a metaphysical will-o'-the-wisp that leaves us floundering in the quagmire. If I question the forces about me, what answer do I get? Molecular attraction and repulsion seem to say, "It is not in us; we are as active in the clod as in the flower." The four principal elements—oxygen, nitrogen, hydrogen, and carbon—say, "It is not in us, because we are from all eternity, and life is not; we form only its physical basis." Warmth and moisture say, "It is not in us; we are only its faithful nurses and handmaidens." The sun says: "It is not in me; I shine on dead worlds as well. I but quicken life after it is planted." The stars say, "It is not in us; we have seen life come and go among myriads of worlds for untold ages." No questioning of the heavens above nor of the earth below can reveal to us the secret we are in quest of.
I can fancy brute matter saying to life: "You tarry with me at your peril. You will always be on the firing-line of my blind, contending forces; they will respect you not; you must take your chances amid my flying missiles. My forces go their eternal round without variableness or shadow of turning, and woe to you if you cross their courses. You maybring all your gods with you—gods of love, mercy, gentleness, altruism; but I know them not. Your prayers will fall upon ears of stone, your appealing gesture upon eyes of stone, your cries for mercy upon hearts of stone. I shall be neither your enemy nor your friend. I shall be utterly indifferent to you. My floods will drown you, my winds wreck you, my fires burn you, my quicksands suck you down, and not know what they are doing. My earth is a theatre of storms and cyclones, of avalanches and earthquakes, of lightnings and cloudbursts; wrecks and ruins strew my course. All my elements and forces are at your service; all my fluids and gases and solids; my stars in their courses will fight on your side, if you put and keep yourself in right relations to them. My atoms and electrons will build your houses, my lightning do your errands, my winds sail your ships, on the same terms. You cannot live without my air and my water and my warmth; but each of them is a source of power that will crush or engulf or devour you before it will turn one hair's-breadth from its course. Your trees will be uprooted by my tornadoes, your fair fields will be laid waste by floods or fires; my mountains will fall on your delicate forms and utterly crush and bury them; my glaciers will overspread vast areas and banish or destroy whole tribes and races of your handiwork; the shrinking and wrinkling crust of my earth will fold in its insensate bosom vast forests of your tropicalgrowths, and convert them into black rock, and I will make rock of the myriad forms of minute life with which you plant the seas; through immense geologic ages my relentless, unseeing, unfeeling forces will drive on like the ploughshare that buries every flower and grass-blade and tiny creature in its path. My winds are life-giving breezes to-day, and the besom of destruction to-morrow; my rains will moisten and nourish you one day, and wash you into the gulf the next; my earthquakes will bury your cities as if they were ant-hills. So you must take your chances, but the chances are on your side. I am not all tempest, or flood, or fire, or earthquake. Your career will be a warfare, but you will win more battles than you will lose. But remember, you are nothing to me, while I am everything to you. I have nothing to lose or gain, while you have everything to gain. Without my soils and moisture and warmth, without my carbon and oxygen and nitrogen and hydrogen, you can do or be nothing; without my sunshine you perish; but you have these things on condition of effort and struggle. You have evolution on condition of pain and failure and the hazard of the warring geologic ages. Fate and necessity rule in my realm. When you fail, or are crushed or swallowed by my remorseless forces, do not blame my gods, or your own; there is no blame, there is only the price to be paid: the hazards of invading the closed circle of my unseeing forces."
In California I saw an epitome of the merciless way inorganic Nature deals with life. An old, dried, and hardened asphalt lake near Los Angeles tells a horrible tale of animal suffering and failure. It had been a pit of horrors for long ages; it was Nature concentrated—her wild welter of struggling and devouring forms through the geologic ages made visible and tangible in a small patch of mingled pitch and animal bones. There was nearly as much bone as pitch. The fate of the unlucky flies that alight upon tangle-foot fly-paper in our houses had been the fate of the victims that had perished here. How many wild creatures had turned appealing eyes to the great unheeding void as they felt themselves helpless and sinking in this all-engulfing pitch! In like manner how many human beings in storms and disasters at sea and in flood and fire upon land have turned the same appealing look to the unpitying heavens! There is no power in the world of physical forces, or apart from our own kind, that heeds us or turns aside for us, or bestows one pitying glance upon us. Life has run, and still runs, the gantlet of a long line of hostile forces, and escapes by dint of fleetness of foot, or agility in dodging, or else by toughness of fibre.
Yet here we are; here is love and charity and mercy and intelligence; the fair face of childhood, the beautiful face of youth, the clear, strong face of manhood and womanhood, and the calm, benignface of old age, seen, it is true, as against a background of their opposites, but seeming to indicate something above chance and change at the heart of Nature. Here is life in the midst of death; but death forever playing into the hands of life; here is the organic in the midst of the inorganic, at strife with it, hourly crushed by it, yet sustained and kept going by its aid.
Vitality is only a word, but it marks a class of phenomena in nature that stands apart from all merely mechanical manifestations in the universe. The cosmos is a vast machine, but in this machine—this tremendous complex of physical forces—there appears, at least on this earth, in the course of its evolution, this something, or this peculiar manifestation of energy, that we call vital. Apparently it is a transient phase of activity in matter, which, unlike other chemical and physical activities, has its beginning and its ending, and out of which have arisen all the myriad forms of terrestrial life. The merely material forces, blind and haphazard from the first, did not arise in matter; they are inseparable from it; they are as eternal as matter itself; but the activities called vital arose in time and place, and must eventually disappear as they arose, while the career of the inorganic elements goes on as if life had never visited the sphere. Was it, or is it, avisitation—somethingab extrathat implies super-mundane, or supernatural, powers?
Added to this wonder is the fact that the vital order has gone on unfolding through the geologic ages, mounting from form to form, or from order to order, becoming more and more complex, passing from the emphasis of size of body, to the emphasis of size of brain, and finally from instinct and reflex activities to free volition, and the reason and consciousness of man; while the purely physical and chemical forces remain where they began. There has been endless change among them, endless shifting of the balance of power, but always the tendency to a dead equilibrium, while the genius of the organic forces has been in the power to disturb the equilibrium and to ride into port on the crest of the wave it has created, or to hang forever between the stable and the unstable.
So there we are, confronted by two apparently contrary truths. It is to me unthinkable that the vital order is not as truly rooted in the constitution of things as are the mechanical and chemical orders; and yet, here we are face to face with its limited, fugitive, or transitional character. It comes and goes like the dews of the morning; it has all the features of an exceptional, unexpected, extraordinary occurrence—of miracle, if you will; but if the light which physical science turns on the universe is not a delusion, if the habit of mind which it begetsis not a false one, then life belongs to the same category of things as do day and night, rain and sun, rest and motion. Who shall reconcile these contradictions?
Huxley spoke for physical science when he said that he did not know what it was that constituted life—what it was that made the "wonderful difference between the dead particles and the living particles of matter appearing in other respects identical." He thought there might be some bond between physico-chemical phenomena, on the one hand, and vital phenomena, on the other, which philosophers will some day find out. Living matter is characterized by "spontaneity of action," which is entirely absent from inert matter. Huxley cannot or does not think of a vital force distinct from all other forces, as the cause of life phenomena, as so many philosophers have done, from Aristotle down to our day. He finds protoplasm to be the physical basis of life; it is one in both the vegetable and animal worlds; the animal takes it from the vegetable, and the vegetable, by the aid of sunlight, takes or manufactures it from the inorganic elements. But protoplasm is living matter. Before there was any protoplasm, what brought about the stupendous change of the dead into the living? Protoplasm makes more protoplasm, as fire makes more fire, but what kindled the first spark of this living flame? Here we corner the mystery, but itis still a mystery that defies us. Cause and effect meet and are lost in each other. Science cannot admit a miracle, or a break in the continuity of life, yet here it reaches a point where no step can be taken. Huxley's illustrations do not help his argument. "Protoplasm," he says, "is the clay of the potter; which, bake it and paint it as he will, remains clay, separated by artifice, and not by nature, from the commonest brick or sun-dried clod." Clay is certainly the physical basis of the potter's art, but would there be any pottery in the world if it contained only clay? Do we not have to think of the potter? In the same way, do we not have to think of something that fashions these myriad forms of life out of protoplasm?—and back of that, of something that begat protoplasm out of non-protoplasmic matter, and started the flame of life going? Life accounts for protoplasm, but what accounts for life? We have to think of the living clay as separated by Nature from the inert "sun-dried clod." There is something in the one that is not in the other. There is really no authentic analogy between the potter's art and Nature's art of life.
The force of the analogy, if it has any, drives us to the conclusion that life is an entity, or an agent, working upon matter and independent of it.
There is more wit than science in Huxley's question, "What better philosophical status has vitality than aquosity?" There is at least this difference:When vitality is gone, you cannot recall it, or reproduce it by your chemistry; but you can recombine the two gases in which you have decomposed water, any number of times, and get your aquosity back again; it never fails; it is a power of chemistry. But vitality will not come at your beck; it is not a chemical product, at least in the same sense that water is; it is not in the same category as the wetness or liquidity of water. It is a name for a phenomenon—the most remarkable phenomenon in nature. It is one that the art of man is powerless to reproduce, while water may be made to go through its cycle of change—solid, fluid, vapor, gas—and always come back to water. Well does the late Professor Brooks, of Johns Hopkins, say that "living things do, in some way and in some degree, control or condition inorganic nature; that they hold their own by setting the mechanical properties of matter in opposition to each other, and that this is their most notable and distinctive characteristic." Does not Ray Lankester, the irate champion of the mechanistic view of life, say essentially the same thing when he calls man the great Insurgent in Nature's camp—"crossing her courses, reversing her processes, and defeating her ends?"
Life appears like the introduction of a new element or force or tendency into the cosmos. Henceforth the elements go new ways, form new compounds, build up new forms, and change the face ofnature. Rivers flow where they never would have flowed without it, mountains fall in a space of time during which they never would have fallen; barriers arise, rough ways are made smooth, a new world appears—the world of man's physical and mental activities.
If the gods of the inorganic elements are neither for nor against us, but utterly indifferent to us, how came we here? Nature's method is always from the inside, while ours is from the outside; hers is circular while ours is direct. We think, as Bergson says, of things created, and of a thing that creates, but things in nature are not created, they are evolved; they grow, and the thing that grows is not separable from the force that causes it to grow. The water turns the wheel, and can be shut off or let on. This is the way of the mechanical world. But the wheels in organic nature go around from something inside them, a kind of perpetual motion, or self-supplying power. They are not turned, they turn; they are not repaired, they repair. The nature of living things cannot be interpreted by the laws of mechanical and chemical things, though mechanics and chemistry play the visible, tangible part in them. If we must discard the notion of a vital force, we may, as Professor Hartog suggests, make use of the term "vital behavior."
Of course man tries everything by himself and his own standards. He knows no intelligence but hisown, no prudence, no love, no mercy, no justice, no economy, but his own, no god but such a one as fits his conception.
In view of all these things, how man got here is a problem. Why the slender thread of his line of descent was not broken in the warrings and upheavals of the terrible geologic ages, what power or agent took a hand in furthering his development, is beyond the reach of our biologic science.
Man's is the only intelligence, as we understand the word, in the universe, and his intelligence demands something akin to intelligence in the nature from which he sprang.
There are three kinds of change in the world in which we live—physical and mechanical change which goes on in time and place among the tangible bodies about us, chemical change which goes on in the world of hidden molecules and atoms of which bodies are composed, and vital change which involves the two former, but which also involves the mysterious principle or activity which we call life. Life comes and goes, but the physical and chemical orders remain. The vegetable and animal kingdoms wax and wane, or disappear entirely, but the physico-chemical forces are as indestructible as matter itself. This fugitive and evanescent character of life, the way it uses and triumphs over the material forces, setting up new chemical activities in matter, sweeping over the land-areas of the earth like a conflagration, lifting the inorganic elements up into myriads of changing and beautiful forms, instituting a vast number of new chemical processes and compounds, defying the laboratory to reproduce it or kindle its least spark—a flame that cannot exist without carbon and oxygen, butof which carbon and oxygen do not hold the secret, a fire reversed, building up instead of pulling down, in the vegetable with power to absorb and transmute the inorganic elements into leaves and fruit and tissue; in the animal with power to change the vegetable products into bone and muscle and nerve and brain, and finally into thought and consciousness; run by the solar energy and dependent upon it, yet involving something which the sunlight cannot give us; in short, an activity in matter, or in a limited part of matter, as real as the physico-chemical activity, but, unlike it, defying all analysis and explanation and all our attempts at synthesis. It is this character of life, I say, that so easily leads us to look upon it as somethingab extra, or super-added to matter, and not an evolution from it. It has led Sir Oliver Lodge to conceive of life as a distinct entity, existing independent of matter, and it is this conception that gives the key to Henri Bergson's wonderful book, "Creative Evolution."
There is possibly or probably a fourth change in matter, physical in its nature, but much more subtle and mysterious than any of the physical changes which our senses reveal to us. I refer to radioactive change, or to the atomic transformation of one element into another, such as the change of radium into helium, and the change of helium into lead—a subject that takes us to the borderland between physics and chemistry where is still debatable ground.
I began by saying that there were three kinds of changes in matter—the physical, the chemical, and the vital. But if we follow up this idea and declare that there are three kinds of force also, claiming this distinction for the third term of our proposition, we shall be running counter to the main current of recent biological science. "The idea that a peculiar 'vital force' acts in the chemistry of life," says Professor Soddy, "is extinct."
"Only chemical and physical agents influence the vital processes," says Professor Czapek, of the University of Prague, "and we need no longer take refuge in mysterious 'vital forces' when we want to explain these."
Tyndall was obliged to think of a force that guided the molecules of matter into the special forms of a tree. This force was in the ultimate particles of matter. But when he came to the brain and to consciousness, he said a new product appeared that defies mechanical treatment.
The attempt of the biological science of our time to wipe out all distinctions between the living and the non-living, solely because scientific analysis reveals no difference, is a curious and interesting phenomenon.
Professor Schäfer, in his presidential address before the British Association in 1912, argued that all the main characteristics of living matter, such as assimilation and disassimilation, growth andreproduction, spontaneous and amœboid movement, osmotic pressure, karyokinesis, etc., were equally apparent in the non-living; therefore he concluded that life is only one of the many chemical reactions, and that it is not improbable that it will yet be produced by chemical synthesis in the laboratory. The logic of the position taken by Professor Schäfer and of the school to which he belongs, demands this artificial production of life—an achievement that seems no nearer than it did a half-century ago. When it has been attained, the problem will be simplified, but the mystery of life will by no means have been cleared up. One follows these later biochemists in working out their problem of the genesis of life with keen interest, but always with a feeling that there is more in their conclusions than is justified by their premises. For my own part, I am convinced that whatever is, is natural, but to obtain life I feel the need of something of a different order from the force that evokes the spark from the flint and the steel, or brings about the reaction of chemical compounds. If asked to explain what this something is that is characteristic of living matter, I should say intelligence.
The new school of biologists start with matter that possesses extraordinary properties—with matter that seems inspired with the desire for life, and behaving in a way that it never will behave in the laboratory. They begin with the earth's surfacewarm and moist, the atmosphere saturated with watery vapor and carbon dioxide and many other complex unstable compounds; then they summon all the material elements of life—carbon, oxygen, hydrogen, and nitrogen, with a little sodium, chlorine, iron, sulphur, phosphorus, and others—and make these run together to form a jelly-like body called a colloid; then they endow this jelly mass with the power of growth, and of subdivision when it gets too large; they make it able to absorb various unstable compounds from the air, giving it internal stores of energy, "the setting free of which would cause automatic movements in the lump of jelly." Thus they lay the foundations of life. This carbonaceous material with properties of movement and subdivision due to mechanical and physical forces is the immediate ancestor of the first imaginary living being, theprotobion. To get thisprotobionthe chemists summon a reagent known as a catalyser. The catalyser works its magic on the jelly mass. It sets up a wonderful reaction by its mere presence, without parting with any of its substance. Thus, if a bit of platinum which has this catalytic power is dropped into a vessel containing a mixture of oxygen and hydrogen, the two gases instantly unite and form water. A catalyser introduced in the primordial jelly liberates energy and gives the substance power to break up the various complex unstable compounds into food, and promote growth and subdivision.In fact, it awakens or imparts a vital force and leads to "indefinite increase, subdivision, and movement."
With Professor Schäfer there is first "the fortuitous production of life upon this globe"—the chance meeting or jostling of the elements that resulted in a bit of living protoplasm, "or a mass of colloid slime" in the old seas, or on their shores, "possessing the property of assimilation and therefore of growth." Here the whole mystery is swallowed at one gulp. "Reproduction would follow as a matter of course," because all material of this physical nature—fluid or semi-fluid in character—"has a tendency to undergo subdivision when its bulk exceeds a certain size."
"A mass of colloidal slime" that has the power of assimilation and of growth and reproduction, is certainly a new thing in the world, and no chemical analysis of it can clear up the mystery. It is easy enough to produce colloidal slime, but to endow it with these wonderful powers so that "the promise and the potency of all terrestrial life" slumbers in it is a staggering proposition.
Whatever the character of this subdivision, whether into equal parts or in the form of buds, "every separate part would resemble the parent in chemical and physical properties, and would equally possess the property of taking in and assimilating suitable material from its liquid environment, growingin bulk and reproducing its like by subdivision. In this way from any beginning of living material a primitive form of life would spread and would gradually people the globe. The establishment of life being once effected, all forms of organization follow under the inevitable laws of evolution." Why all forms of organization—why the body and brain of man—must inevitably follow from the primitive bit of living matter, is just the question upon which we want light. The proposition begs the question. Certainly when you have got the evolutionary process once started in matter which has these wonderful powers, all is easy. The professor simply describes what has taken place and seems to think that the mystery is thereby cleared up, as if by naming all the parts of a machine and their relation to one another, the machine is accounted for. What caused the iron and steel and wood of the machine to take this special form, while in other cases the iron and steel and wood took other radically different forms, and vast quantities of these substances took no form at all?
In working out the evolution of living forms by the aid of the blind physical and chemical agents alone, Professor Schäfer unconsciously ascribes the power of choice and purpose to the individual cells, as when he says that the cells of the external layer sink below the surface for better protection and better nutrition. It seems to have been a matter ofchoice or will that the cells developed a nervous system in the animal and not in the vegetable. Man came because a few cells in some early form of life acquired a slightly greater tendency to react to an external stimulus. In this way they were brought into closer touch with the outer world and thereby gained the lead of their duller neighbor cells, and became the real rulers of the body, and developed the mind.
It is bewildering to be told by so competent a person as Professor Schäfer that at bottom there is no fundamental difference between the living and non-living. We need not urge the existence of a peculiar vital force, as distinct from all other forces, but all distinctions between things are useless if we cannot say that a new behavior is set up in matter which we describe by the word "vital," and that a new principle is operative in organized matter which we must call "intelligence." Of course all movements and processes of living beings are in conformity with the general laws of matter, but does such a statement necessarily rule out all idea of the operation of an organizing and directing principle that is not operative in the world of inanimate things?
In Schäfer's philosophy evolution is purely a mechanical process—there is no inborn tendency, no inherent push, no organizing effort, but all results from the blind groping and chance jostling of the inorganic elements; from the molecules of undifferentiatedprotoplasm to the brain of a Christ or a Plato, is just one series of unintelligent physical and chemical activities in matter.
May we not say that all the marks or characteristics of a living body which distinguish it in our experience from an inanimate body, are of a non-scientific character, or outside the sphere of experimental science? We recognize them as readily as we distinguish day from night, but we cannot describe them in the fixed terms of science. When we say growth, metabolism, osmosis, the colloidal state, science points out that all this may be affirmed of inorganic bodies. When we say a life principle, a vital force or soul or spirit or intelligence, science turns a deaf ear.
The difference between the living and the non-living is not so much a physical difference as a metaphysical difference. Living matter is actuated by intelligence. Its activities are spontaneous and self-directing. The rock, and the tree that grows beside it, and the insects and rodents that burrow under it, may all be made of one stuff, but their difference to the beholder is fundamental; there is an intelligent activity in the one that is not in the other. Now no scientific analysis of a body will reveal the secret of this activity. As well might your analysis of a phonographic record hope to disclose a sonata of Beethoven latent in the waving lines. No power of chemistry could reveal any difference between thegray matter of Plato's brain and that of the humblest citizen of Athens. All the difference between man, all that makes a man a man, and an ox an ox, is beyond the reach of any of your physico-chemical tests. By the same token the gulf that separates the organic from the inorganic is not within the power of science to disclose. The biochemist is bound to put life in the category of the material forces because his science can deal with no other. To him the word "vital" is a word merely, it stands for no reality, and the secret of life is merely a chemical reaction. A living body awakens a train of ideas in our minds that a non-living fails to awaken—a train of ideas that belong to another order from that awakened by scientific demonstration. We cannot blame science for ruling out that which it cannot touch with its analysis, or repeat with its synthesis. The phenomena of life are as obvious to us as anything in the world; we know their signs and ways, and witness their power, yet in the alembic of our science they turn out to be only physico-chemical processes; hence that is all there is of them. Vitality, says Huxley, has no more reality than the horology of a clock. Yet Huxley sees three equal realities in the universe—matter, energy, and consciousness. But consciousness is the crown of a vital process. Hence it would seem as if there must be something more real in vitality than Huxley is willing to admit.
Nearly all the later biologists or biological philosophers are as shy of the term "vital force," and even of the word "vitality," as they are of the words "soul," "spirit," "intelligence," when discussing natural phenomena. To experimental science such words have no meaning because the supposed realities for which they stand are quite beyond the reach of scientific analysis. Ray Lankester, in his "Science from an Easy Chair," following Huxley, compares vitality with aquosity, and says that to have recourse to a vital principle or force to explain a living body is no better philosophy than to appeal to a principle of aquosity to explain water. Of course words are words, and they have such weight with us that when we have got a name for a thing it is very easy to persuade ourselves that the thing exists. The terms "vitality," "vital force," have long been in use, and it is not easy to convince one's self that they stand for no reality. Certain it is that living and non-living matter are sharply separated, though when reduced to their chemical constituents in the laboratory they are found to be identical. The carbon, the hydrogen, the nitrogen, the oxygen, and the lime, sulphur, iron, etc., in a living body are in no way peculiar, but are the same as these elements in the rocks and the soil. We are all made of one stuff; a man and his dog are made of one stuff; an oak and a pine aremade of one stuff; Jew and Gentile are made of one stuff. Should we be justified, then, in saying that there is no difference between them? There is certainly a moral and an intellectual difference between a man and his dog, if there is no chemical and mechanical difference. And there is as certainly as wide or a wider difference between living and non-living matter, though it be beyond the reach of science to detect. For this difference we have to have a name, and we use the words "vital," "vitality," which seem to me to stand for as undeniable realities as the words heat, light, chemical affinity, gravitation. There is not a principle of roundness, though "nature centres into balls," nor of squareness, though crystallization is in right lines, nor of aquosity, though two thirds of the surface of the earth is covered with water. Can we on any better philosophical grounds say that there is a principle of vitality, though the earth swarms with living beings? Yet the word vitality stands for a reality, it stands for a peculiar activity in matter—for certain movements and characteristics for which we have no other term. I fail to see any analogy between aquosity and that condition of matter we call vital or living. Aquosity is not an activity, it is a property, the property of wetness; viscosity is a term to describe other conditions of matter; solidity, to describe still another condition; and opacity and transparency, to describe still others—as theyaffect another of our senses. But the vital activity in matter is a concrete reality. With it there goes the organizing tendency or impulse, and upon it hinges the whole evolutionary movement of the biological history of the globe. We can do all sorts of things with water and still keep its aquosity. If we resolve it into its constituent gases we destroy its aquosity, but by uniting these gases chemically we have the wetness back again. But if a body loses its vitality, its life, can we by the power of chemistry, or any other power within our reach, bring the vitality back to it? Can we make the dead live? You may bray your living body in a mortar, destroy every one of its myriad cells, and yet you may not extinguish the last spark of life; the protoplasm is still living. But boil it or bake it and the vitality is gone, and all the art and science of mankind cannot bring it back again. The physical and chemical activities remain after the vital activities have ceased. Do we not then have to supply a non-chemical, a non-physical force or factor to account for the living body? Is there no difference between the growth of a plant or an animal, and the increase in size of a sand-bank or a snow-bank, or a river delta? or between the wear and repair of a working-man's body and the wear and repair of the machine he drives? Excretion and secretion are not in the same categories. The living and the non-living mark off the two grand divisions of matter in the world in which we live, as no twoterms merely descriptive of chemical and physical phenomena ever can. Life is a motion in matter, but of another order from that of the physico-chemical, though inseparable from it. We may forego the convenient term "vital force." Modern science shies at the term "force." We must have force or energy or pressure of some kind to lift dead matter up into the myriad forms of life, though in the last analysis of it it may all date from the sun. When it builds a living body, we call it a vital force; when it builds a gravel-bank, or moves a glacier, we call it a mechanical force; when it writes a poem or composes a symphony, we call it a psychic force—all distinctions which we cannot well dispense with, though of the ultimate reality for which these terms stand we can know little. In the latest science heat and light are not substances, though electricity is. They are peculiar motions in matter which give rise to sensations in certain living bodies that we name light and heat, as another peculiar motion in matter gives rise to a sensation we call sound. Life is another kind of motion in certain aggregates of matter—more mysterious or inexplicable than all others because it cannot be described in terms of the others, and because it defies the art and science of man to reproduce.
Though the concepts "vital force" and "life principle" have no standing in the court of modern biological science, it is interesting to observe howoften recourse is had by biological writers to terms that embody the same idea. Thus the German physiologist Verworn, the determined enemy of the old conception of life, in his great work on "Irritability," has recourse to "the specific energy of living substances." One is forced to believe that without this "specific energy" his "living substances" would never have arisen out of the non-living.
Professor Moore, of Liverpool University, as I have already pointed out while discussing the term "vital force," invents a new phrase, "biotic energy," to explain the same phenomena. Surely a force by any other name is no more and no less potent. Both Verworn and Moore feel the need, as we all do, of some term, or terms, by which to explain that activity in matter which we call vital. Other writers have referred to "a peculiar power of synthesis" in plants and animals, which the inanimate forms do not possess.
Ray Lankester, to whom I have already referred in discussing this subject, helps himself out by inventing, not a new force, but a new substance in which he fancies "resides the peculiar property of living matter." He calls this hypothetical substance "plasmogen," and thinks of it as an ultimate chemical compound hidden in protoplasm. Has this "ultimate molecule of life" any more scientific or philosophical validity than the old conception of a vital force? It looks very much like another namefor the same thing—an attempt to give the mind something to take hold of in dealing with the mystery of living things. This imaginary "life-stuff" of the British scientist is entirely beyond the reach of chemical analysis; no man has ever seen it or proved its existence. In fact it is simply an invention of Ray Lankester to fill a break in the sequence of observed phenomena. Something seems to possess the power of starting or kindling that organizing activity in a living body, and it seems to me it matters little whether we call it "plasmogen," or a "life principle," or "biotic energy," or what not; it surely leavens the loaf. Matter takes on new activities under its influence. Ray Lankester thinks that plasmogen came into being in early geologic ages, and that the conditions which led to its formation have probably never recurred. Whether he thinks its formation was merely a chance hit or not, he does not say.