Still the problem of living things haunts my mind and, let me warn my reader, will continue to haunt it throughout the greater part of this volume. The final truth about it refuses to be spoken. Every effort to do so but gives one new evidence of how insoluble the problem is.

In this world of change is there any other change to be compared with that in matter, from the dead to the living?—a change so great that most minds feel compelled to go outside of matter and invoke some super-material force or agent to account for it. The least of living things is so wonderful, the phenomena it exhibits are so fundamentally unlike those of inert matter, that we invent a word for it, vitality; and having got the word, we conceive of a vital force or principle to explain vital phenomena. Hence vitalism—a philosophy of living things, more or less current in the world from Aristotle's time down to our own. It conceives of something in nature super-mechanical and super-chemical, though inseparably bound up with these things. There is no life without material and chemical forces, but material and chemical forces do not hold the secret of life. This is vitalism as opposed to mechanism, or scientific materialism, which is the doctrine of the all-sufficiency of the physical forces operating in the inorganic world to give rise to all the phenomena of the organic world—a doctrine coming more and more in vogue with the progress of physical science. Without holding to any belief in the supernatural or the teleological, and while adhering to the idea that there has been, and can be, no break in the causal sequence in this world, may one still hold to some form of vitalism, and see in life something more than applied physics and chemistry?

Is biology to be interpreted in the same physical and chemical terms as geology? Are biophysics and geophysics one and the same? One may freely admit that there cannot be two kinds of physics, nor two kinds of chemistry—not one kind for a rock, and another kind for a tree, or a man. There are not two species of oxygen, nor two of carbon, nor two of hydrogen and nitrogen—one for living and one for dead matter. The water in the human body is precisely the same as the water that flows by in the creek or that comes down when it rains; and the sulphur and the lime and the iron and the phosphorus and the magnesium are identical, so far as chemical analysis can reveal, in the organic and the inorganic worlds. But are we not compelled to think of a kind of difference between a living and a non-living body that we cannot fit into any of the mechanical or chemical concepts that we apply to the latter? Professor Loeb, with his "Mechanistic Conception of Life"; Professor Henderson, of Harvard, with his "Fitness of the Environment"; Professor Le Dantec, of the Sorbonne in Paris, with his volume on "The Nature and Origin of Life," published a few years since; Professor SchÄfer, President of the British Association, Professor Verworn of Bonn, and many others find in the laws and properties of matter itself a sufficient explanation of all the phenomena of life. They look upon the living body as only the sum of its physical and chemical activities; they do not seem to feel the need of accounting for life itself—for that something which confers vitality upon the heretofore non-vital elements. That there is new behavior, that there are new chemical compounds called organic,—tens of thousands of them not found in inorganic nature,—that there are new processes set up in aggregates of matter,—growth, assimilation, metabolism, reproduction, thought, emotion, science, civilization,—no one denies.

How are we going to get these things out of the old physics and chemistry without some new factor or agent or force? To help ourselves out here with a "vital principle," or with spirit, or a creative impulse, as Bergson does, seems to be the only course open to certain types of mind. Positive science cannot follow us in this step, because science is limited to the verifiable. The stream of forces with which it deals is continuous; it must find the physical equivalents of all the forces that go into the body in the output of the body, and it cannot admit of a life force which it cannot trace to the physical forces.

What has science done to clear up this mystery of vitality? Professor Loeb, our most eminent experimental biologist, has succeeded in fertilizing the eggs of some low forms of sea life by artificial means; and in one instance, at least, it is reported that the fatherless form grew to maturity. This is certainly an interesting fact, but takes us no nearer the solution of the mystery of vitality than the fact that certain chemical compounds may stimulate the organs of reproduction helps to clear up the mystery of generation; or the fact that certain other chemical compounds help the digestive and assimilative processes and further the metabolism of the body assists in clearing up the mystery that attaches to these things. In all such cases we have the living body to begin with. The egg of the sea-urchin and the egg of the jelly-fish are living beings that responded to certain chemical substances, so that a process is set going in their cell life that is equivalent to fertilization. It seems to me that the result of all Professor Loeb's valuable inquiries is only to give us a more intimate sense of how closely mechanical and chemical principles are associated and identified with all the phenomena of life and with all animal behavior. Given a living organism, mechanics and chemistry will then explain much of its behavior—practically all the behavior of the lower organisms, and much of that of the higher. Even when we reach man, our reactions to the environment and to circumstances play a great part in our lives; but dare we say that will, liberty of choice, ideation, do not play a part also? How much reality there is in the so-called animal will, is a problem; but that there is a foundation for our belief in the reality of the human will, I, for one, do not for a moment doubt. The discontinuity here is only apparent and not real. We meet with the same break when we try to get our mental states, our power of thought—a poem, a drama, a work of art, a great oration—out of the food we eat; but life does it, though our science is none the wiser for it. Our physical life forms a closed circle, science says, and what goes into our bodies as physical force, must come out in physical force, or as some of its equivalents. Well, one of the equivalents, transformed by some unknown chemism within us, is our psychic force, or states of consciousness. The two circles, the physical and the psychical, are not concentric, as Fiske fancied, but are linked in some mysterious way.

Professor Loeb is a master critic of the life processes; he and his compeers analyze them as they have never been analyzed before; but the solution of the great problem of life that we are awaiting does not come. A critic may resolve all of Shakespeare's plays into their historic and other elements, but that will not account for Shakespeare. Nature's synthesis furnishes occasions for our analysis. Most assuredly all psychic phenomena have a physical basis; we know the soul only through the body; but that they are all of physico-chemical origin, is another matter.

II

Biological science has hunted the secret of vitality like a detective; and it has done some famous work; but it has not yet unraveled the mystery. It knows well the part played by carbon, oxygen, and hydrogen in organic chemistry, that without water and carbon dioxide there could be no life; it knows the part played by light, air, heat, gravity, osmosis, chemical affinity, and all the hundreds or thousands of organic compounds; it knows the part played by what are called the enzymes, or ferments, in all living bodies, but it does not know the secret of these ferments; it knows the part played by colloids, or jelly-like compounds, that there is no living body without colloids, though there are colloid bodies that are not living; it knows the part played by oxidation, that without it a living body ceases to function, though everywhere all about us is oxidation without life; it knows the part played by chlorophyll in the vegetable kingdom, and yet how chlorophyll works such magic upon the sun's rays, using the solar energy to fix the carbon of carbonic acid in the air, and thereby storing this energy as it is stored in wood and coal and in much of the food we consume, is a mystery. Chemistry cannot repeat the process in its laboratories. The fungi do not possess this wonderful chlorophyllian power, and hence cannot use the sunbeam to snatch their carbon from the air; they must get it from decomposed vegetable matter; they feed, as the animals do, upon elements that have gone through the cycle of vegetable life. The secret of vegetable life, then, is in the green substance of the leaf where science is powerless to unlock it. Conjure with the elements as it may, it cannot produce the least speck of living matter. It can by synthesis produce many of the organic compounds, but only from matter that has already been through the organic cycle. It has lately produced rubber, but from other products of vegetable life.

As soon as the four principal elements, carbon, oxygen, hydrogen, and nitrogen, that make up the living body, have entered the world of living matter, their activities and possible combinations enormously increase; they enter into new relations with one another and form compounds of great variety and complexity, characterized by the instability which life requires. The organic compounds are vastly more sensitive to light and heat and air than are the same elements in the inorganic world. What has happened to them? Chemistry cannot tell us. Oxidation, which is only slow combustion, is the main source of energy in the body, as it is in the steam-engine. The storing of the solar energy, which occurs only in the vegetable, is by a process of reduction, that is, the separation of the carbon and oxygen in carbonic acid and water. The chemical reactions which liberate energy in the body are slow; in dead matter they are rapid and violent, or explosive and destructive. It is the chemistry in the leaf of the plant that diverts or draws the solar energy into the stream of life, and how it does it is a mystery.

The scientific explanations of life phenomena are all after the fact; they do not account for the fact; they start with the ready-made organism and then reduce its activities and processes to their physical equivalents. Vitality is given, and then the vital processes are fitted into mechanical and chemical concepts, or into moulds derived from inert matter—not a difficult thing to do, but no more an explanation of the mystery of vitality than a painting or a marble bust of Tyndall would be an explanation of that great scientist.

All Professor Loeb's experiments and criticisms throw light upon the life processes, or upon the factors that take part in them, but not upon the secret of the genesis of the processes themselves. Amid all the activities of his mechanical and chemical factors, there is ever present a factor which he ignores, which his analytical method cannot seize; namely, what Verworn calls "the specific energy of living substance." Without this, chemism and mechanism would work together to quite other ends. The water in the wave, and the laws that govern it, do not differ at all from the water and its laws that surround it; but unless one takes into account the force that makes the wave, an analysis of the phenomena will leave one where he began.

Professor Le Dantec leaves the subject where he took it up, with the origin of life and the life processes unaccounted for. His work is a description, and not an explanation. All our ideas about vitality, or an unknown factor in the organic world, he calls "mystic" and unscientific. A sharp line of demarcation between living and non-living bodies is not permissible. This, he says, is the anthropomorphic error which puts some mysterious quality or force in all bodies considered to be living. To Le Dantec, the difference between the quick and the dead is of the same order as the difference which exists between two chemical compounds—for example, as that which exists between alcohol and an aldehyde, a liquid that has two less atoms of hydrogen in its composition. Modify your chemistry a little, add or subtract an atom or two, more or less, of this or that gas, and dead matter thrills into life, or living matter sinks to the inert. In other words, life is the gift of chemistry, its particular essence is of the chemical order—a bold inference from the fact that there is no life without chemical reactions, no life without oxidation. Yet chemical reactions in the laboratory cannot produce life. With Le Dantec, biology, like geology and astronomy, is only applied mechanics and chemistry.

III

Such is the result of the rigidly objective study of life—the only method analytical science can pursue. The conception of vitality as a factor in itself answers to nothing that the objective study of life can disclose; such a study reveals a closed circle of physical forces, chemical and mechanical, into which no immaterial force or principle can find entrance. "The fact of being conscious," Le Dantec says with emphasis, "does not intervene in the slightest degree in directing vital movements." But common sense and everyday observation tell us that states of consciousness do influence the bodily processes—influence the circulation, the digestion, the secretions, the respiration.

An objective scientific study of a living body yields results not unlike those which we might get from an objective study of a book considered as something fabricated—its materials, its construction, its typography, its binding, the number of its chapters and pages, and so on—without giving any heed to the meaning of the book—its ideas, the human soul and personality that it embodies, the occasion that gave rise to it, indeed all its subjective and immaterial aspects. All these things, the whole significance of the volume, would elude scientific analysis. It would seem to be a manufactured article, representing only so much mechanics and chemistry. It is the same with the living body. Unless we permit ourselves to go behind the mere facts, the mere mechanics and chemistry of life phenomena, and interpret them in the light of immaterial principles, in short, unless we apply some sort of philosophy to them, the result of our analysis will be but dust in our eyes, and ashes in our mouths. Unless there is something like mind or intelligence pervading nature, some creative and transforming impulse that cannot be defined by our mechanical concepts, then, to me, the whole organic world is meaningless. If man is not more than an "accident in the history of the thermic evolution of the globe," or the result of the fortuitous juxtaposition and combination of carbonic acid gas and water and a few other elements, what shall we say? It is at least a bewildering proposition.

Could one by analyzing a hive of bees find out the secret of its organization—its unity as an aggregate of living insects? Behold its wonderful economics, its division of labor, its complex social structure,—the queen, the workers, the drones,—thousands of bees without any head or code of laws or directing agent, all acting as one individual, all living and working for the common good. There is no confusion or cross-purpose in the hive. When the time of swarming comes, they are all of one mind and the swarm comes forth. Who or what decides who shall stay and who shall go? When the honey supply fails, or if it fail prematurely, on account of a drought, the swarming instinct is inhibited, and the unhatched queens are killed in their cells. Who or what issues the regicide order? We can do no better than to call it the Spirit of the Hive, as Maeterlinck has done. It is a community of mind. What one bee knows and feels, they all know and feel at the same instant. Something like that is true of a living body; the cells are like the bees: they work together, they build up the tissues and organs, some are for one thing and some for another, each community of cells plays its own part, and they all pull together for the good of the whole. We can introduce cells and even whole organs, for example a kidney from another living body, and all goes well; and yet we cannot find the seat of the organization. Can we do any better than to call it the Spirit of the Body?

IV

Our French biologist is of the opinion that the artificial production of that marvel of marvels, the living cell, will yet take place in the laboratory. But the enlightened mind, he says, does not need such proof to be convinced that there is no essential difference between living and non-living matter.

Professor Henderson, though an expounder of the mechanistic theory of the origin of life, admits that he does not know of a biological chemist to whom the "mechanistic origin of a cell is scientifically imaginable." Like Professor Loeb, he starts with the vital; how he came by it we get no inkling; he confesses frankly that the biological chemist cannot even face the problem of the origin of life. He quotes with approval a remark of Liebig's, as reported by Lord Kelvin, that he (Liebig) could no more believe that a leaf or a flower could be formed or could grow by chemical forces "than a book on chemistry, or on botany, could grow out of dead matter." Is not this conceding to the vitalists all that they claim? The cell is the unit of life; all living bodies are but vast confraternities of cells, some billions or trillions of them in the human body; the cell builds up the tissues, the tissues build up the organs, the organs build up the body. Now if it is not thinkable that chemism could beget a cell, is it any more thinkable that it could build a living tissue, and then an organ, and then the body as a whole? If there is an inscrutable something at work at the start, which organizes that wonderful piece of vital mechanism, the cell, is it any the less operative ever after, in all life processes, in all living bodies and their functions,—the vital as distinguished from the mechanical and chemical? Given the cell, and you have only to multiply it, and organize these products into industrial communities, and direct them to specific ends,—certainly a task which we would not assign to chemistry or physics any more than we would assign to them the production of a work on chemistry or botany,—and you have all the myriad forms of terrestrial life.

The cell is the parent of every living thing on the globe; and if it is unthinkable that the material and irrational forces of inert matter could produce it, then mechanics and chemistry must play second fiddle in all that whirl and dance of the atoms that make up life. And that is all the vitalists claim. The physico-chemical forces do play second fiddle; that inexplicable something that we call vitality dominates and leads them. True it is that a living organism yields to scientific analysis only mechanical and chemical forces—a fact which only limits the range of scientific analysis, and which by no means exhausts the possibilities of the living organism. The properties of matter and the laws of matter are intimately related to life, yea, are inseparable from it, but they are by no means the whole story. Professor Henderson repudiates the idea of any extra-physical influence as being involved in the processes of life, and yet concedes that the very foundation of all living matter, yea, the whole living universe in embryo—the cell—is beyond the possibilities of physics and chemistry alone. Mechanism and chemism are adequate to account for astronomy and geology, and therefore, he thinks, are sufficient to account for biology, without calling in the aid of any Bergsonian life impulse. Still these forces stand impotent before that microscopic world, the cell, the foundation of all life.

Our professor makes the provisional statement, not in obedience to his science, but in obedience to his philosophy, that something more than mechanics and chemistry may have had a hand in shaping the universe, some primordial tendency impressed upon or working in matter "just before mechanism begins to act"—"a necessary and preËstablished associate of mechanism." So that if we start with the universe, with life, and with this tendency, mechanism will do all the rest. But this is not science, of course, because it is not verifiable; it is practically the philosophy of Bergson.

The cast-iron conclusions of physical science do pinch the Harvard professor a bit, and he pads them with a little of the Bergsonian philosophy. Bergson himself is not pinched at all by the conclusions of positive science. He sees that we, as human beings, cannot live in this universe without supplementing our science with some sort of philosophy that will help us to escape from the fatalism of matter and force into the freedom of the spiritual life. If we are merely mechanical and chemical accidents, all the glory of life, all the meaning of our moral and spiritual natures, go by the board.

Professor Henderson shows us how well this planet, with its oceans and continents, and its mechanical and chemical forces and elements, is suited to sustain life, but he brings us no nearer the solution of the mystery than we were before. His title, to begin with, is rather bewildering. Has the "fitness of the environment" ever been questioned? The environment is fit, of course, else living bodies would not be here. We are used to taking hold of the other end of the problem. In living nature the foot is made to fit the shoe, and not the shoe the foot. The environment is the mould in which the living organism is cast. Hence, it seems to me, that seeking to prove the fitness of the environment is very much like seeking to prove the fitness of water for fish to swim in, or the fitness of the air for birds to fly in. The implication seems to be made that the environment anticipates the organism, or meets it half way. But the environment is rather uncompromising. Man alone modifies his environment by the weapon of science; but not radically; in the end he has to fit himself to it. Life has been able to adjust itself to the universal forces and so go along with them; otherwise we should not be here. We may say, humanly speaking, that the water is friendly to the swimmer, if he knows how to use it; if not, it is his deadly enemy. The same is true of all the elements and forces of nature. Whether they be for or against us, depends upon ourselves. The wind is never tempered to the shorn lamb, the shorn lamb must clothe itself against the wind. Life is adaptive, and this faculty of adaptation to the environment, of itself takes it out of the category of the physico-chemical. The rivers and seas favor navigation, if we have gumption enough to use and master their forces. The air is good to breathe, and food to eat, for those creatures that are adapted to them. Bergson thinks, not without reason, that life on other planets may be quite different from what it is on our own, owing to a difference in chemical and physical conditions. Change the chemical constituents of sea water, and you radically change the lower organisms. With an atmosphere entirely of oxygen, the processes of life would go on more rapidly and perhaps reach a higher form of development. Life on this planet is limited to a certain rather narrow range of temperature; the span may be the same in other worlds, but farther up or farther down the scale. Had the air been differently constituted, would not our lungs have been different? The lungs of the fish are in his gills: he has to filter his air from a much heavier medium. The nose of the pig is fitted for rooting; shall we say, then, that the soil was made friable that pigs might root in it? The webbed foot is fitted to the water; shall we say, then, that water is liquid in order that geese and ducks may swim in it? One more atom of oxygen united to the two atoms that go to make the molecule of air, and we should have had ozone instead of the air we now breathe. How unsuited this would have made the air for life as we know it! Oxidation would have consumed us rapidly. Life would have met this extra atom by some new device.

One wishes Professor Henderson had told us more about how life fits itself to the environment—how matter, moved and moulded only by mechanical and chemical forces, yet has some power of choice that a machine does not have, and can and does select the environment best suited to its well-being. In fact, that it should have, or be capable of, any condition of well-being, if it is only a complex of physical and chemical forces, is a problem to wrestle with. The ground we walk on is such a complex, but only the living bodies it supports have conditions of well-being.

Professor Henderson concedes very little to the vitalists or the teleologists. He is a thorough mechanist. "Matter and energy," he says, "have an original property, assuredly not by chance, which organizes the universe in space and time." Where or how matter got this organizing property, he offers no opinion. "Given the universe, life, and the tendency [the tendency to organize], mechanism is inductively proved sufficient to account for all phenomena." Biology, then, is only mechanics and chemistry engaged in a new rÔle without any change of character; but what put them up to this new rÔle? "The whole evolutionary process, both cosmic and organic, is one, and the biologist may now rightly regard the universe in its very essence as biocentric."

V

Another Harvard voice is less pronounced in favor of the mechanistic conception of life. Professor Rand thinks that in a mechanically determined universe, "our conscious life becomes a meaningless replica of an inexorable physical concatenation"—the soul the result of a fortuitous concourse of atoms. Hence all the science and art and literature and religion of the world are merely the result of a molecular accident.

Dr. Rand himself, in wrestling with the problem of organization in a late number of "Science," seems to hesitate whether or not to regard man as a molecular accident, an appearance presented to us by the results of the curious accidents of molecules—which is essentially Professor Loeb's view; or whether to look upon the living body as the result of a "specific something" that organizes, that is, of "dominating organic agencies," be they psychic or super-mundane, which dominate and determine the organization of the different parts of the body into a whole. Yet he is troubled with the idea that this specific something may be "nothing more than accidental chemical peculiarities of cells." But would these accidental peculiarities be constant? Do accidents happen millions of times in the same way? The cell is without variableness or shadow of turning. The cells are the minute people that build up all living forms, and what prompts them to build a man in the one case, and the man's dog in another, is the mystery that puzzles Professor Rand. "Tissue cells," he says, "are not structures like stone blocks laboriously carved and immovably cemented in place. They are rather like the local eddies in an ever-flowing and ever-changing stream of fluids. Substance which was at one moment a part of a cell, passes out and a new substance enters. What is it that prevents the local whirl in this unstable stream from changing its form? How is it that a million muscle cells remain alike, collectively ready to respond to a nerve impulse?" According to one view, expressed by Professor Rand, "Organization is something that we read into natural phenomena. It is in itself nothing." The alternative view holds that there is a specific organizing agent that brings about the harmonious operation of all the organs and parts of the system—a superior dynamic force controlling and guiding all the individual parts.

A most determined and thorough-going attempt to hunt down the secret of vitality, and to determine how far its phenomena can be interpreted in terms of mechanics and chemistry, is to be found in Professor H. W. Conn's volume entitled "The Living Machine." Professor Conn justifies his title by defining a machine as "a piece of apparatus so designed that it can change one kind of energy into another for a definite purpose." Of course the adjective "living" takes it out of the category of all mere mechanical devices and makes it super-mechanical, just as Haeckel's application of the word "living" to his inorganics ("living inorganics"), takes them out of the category of the inorganic. In every machine, properly so called, all the factors are known; but do we know all the factors in a living body? Professor Conn applies his searching analysis to most of the functions of the human body, to digestion, to assimilation, to circulation, to respiration, to metabolism, and so on, and he finds in every function something that does not fall within his category—some force not mechanical nor chemical, which he names vital.

In following the processes of digestion, all goes well with his chemistry and his mechanics till he comes to the absorption of food-particles, or their passage through the walls of the intestines into the blood. Here, the ordinary physical forces fail him, and living matter comes to his aid. The inner wall of the intestine is not a lifeless membrane, and osmosis will not solve the mystery. There is something there that seizes hold of the droplets of oil by means of little extruded processes, and then passes them through its own body to excrete them on an inner surface into the blood-vessels. "This fat absorption thus appears to be a vital process and not one simply controlled by physical forces like osmosis. Here our explanation runs against what we call 'vital power' of the ultimate elements of the body." Professor Conn next analyzes the processes of circulation, and his ready-made mechanical concepts carry him along swimmingly, till he tries to explain by them the beating of the heart, and the contraction of the small blood-vessels which regulate the blood-supply. Here comes in play the mysterious vital power again. He comes upon the same power when he tries to determine what it is that enables the muscle-fibre to take from the lymph the material needed for its use, and to discard the rest. The fibre acts as if it knew what it wanted—a very unmechanical attribute.

Then Professor Conn applies his mechanics and chemistry to the respiratory process and, of course, makes out a very clear case till he comes to the removal of the waste, or ash. The steam-engine cannot remove its own ash; the "living machine" can. Much of this ash takes the form of urea, and "the seizing upon the urea by the kidney cells is a vital phenomenon." Is not the peristaltic movement of the bowels, by which the solid matter is removed, also a vital phenomenon? Is not the conception of a pipe or a tube that forces semi-fluid matter along its hollow interior, by the contraction of its walls, quite beyond the reach of mechanics? The force is as mechanical as the squeezing of the bulb of a syringe by the hand, but in the case of the intestines, what does the squeezing? The vital force?

When the mechanical and chemical concepts are applied to the phenomena of the nervous system, they work very well till we come to mental phenomena. When we try to correlate physical energy with thought or consciousness, we are at the end of our tether. Here is a gulf we cannot span. The theory of the machine breaks down. Some other force than material force is demanded here, namely, psychical,—a force or principle quite beyond the sphere of the analytic method.

Hence Professor Conn concludes that there are vital factors and that they are the primal factors in the organism. The mechanical and chemical forces are the secondary factors. It is the primal factors that elude scientific analysis. Why a muscle contracts, or why a gland secretes, or "why the oxidation of starch in the living machine gives rise to motion, growth, and reproduction, while if the oxidation occurs in the chemist's laboratory ... it simply gives rise to heat," are questions he cannot answer. In all his inquiries into the parts played by mechanical and chemical laws in the organism, he is compelled to "assume as their foundation the simple vital properties of living phenomena."

VI

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 active or 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 something sui 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 the circulation 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 amoeba 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 vital x?"

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 such thing as 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. That which 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.

VII

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 new and 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; but whether 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."