Popular Science Monthly/Volume 43/August 1893/The Material View of Life and its Relation to the Spiritual
By Prof. GRAHAM LUSK,
ASSISTANT PROFESSOR OF PHYSIOLOGY, YALE MEDICAL SCHOOL.
WE live in a material age. Old beliefs are being supplanted by what seem to be new truths. The student finds on every hand vast volumes of learning bequeathed to him by those who have labored before him; and he who plunges deeply into this onward-rushing tide of material truths is often startled to find there an undertow sucking away the spiritual foundation. Skeptics, in scorn of latter-day religion, refer to the middle ages as the ages of faith. Christians, half dismayed, ask themselves. Is mankind to be swallowed up in the abyss of materialism?
It is the purpose of this paper to discuss life from a strictly material standpoint, and afterward to show that belief in the material interpretation does not cut one off from belief in the spiritual.
My own ideas have been largely influenced by German thought. Those who have had the privilege of listening to the lectures of Prof. Carl Yoit in Munich will recognize in this paper many traces of his teaching. Through him I received instruction in the material view of life.
The idea of the world held by Aristotle was that all things were made up of certain elementary matter, qualified by four properties—hot, cold, wet, and dry. Matter, with the properties cold and dry, was earth; with cold and wet, water; with hot and wet, air; and with hot and dry, fire. Different bodies varied from each other as they contained different proportions of the properties. These properties could be driven off from matter—that is to say, were separable from matter. Thus, the alchemists of the middle ages thought if they could drive a certain property out of mercury, or put a new one into it, clearly they would produce gold.
In like manner these same principles came into use for the explanation of life. During life there was a property present which departed at death—a living principle, a "vital force."
Galen, who was born at Troy, and who died at Rome a. d. 200, applied the learning of Aristotle to his practice of medicine. Man, he said, is but matter containing certain properties. If these properties be in correct proportion, well and good; but if the balance be upset, sickness results. The therapeutics of Galen consisted, therefore, in restoring the lost property. If the patient had a chill, he put him in a warm bath; if he had a fever, he put him in a cold bath.
Van Helmont, whose work belongs chiefly to the first half of the seventeenth century, tells us of the existence of an Archæus, and in this theory he was supported by Paracelsus. The Archæus was a spirit which had its abode in the stomach of man. If the Archæus were well nourished, he was pleased and happy; but if anything disagreeable reached him, he made his displeasure painfully evident, and if something were not done to appease his anger, he betook himself off, and the man was dead.
Our present views are entirely different. Properties are not separable from matter. Properties are inherent in matter. Ujjon this knowledge our modern opinions are based. We have spoken of a belief that life depended on a property—a "vital force." A "force" may be defined as something that can not be explained. The laws of gravitation stand as Newton left them, but what the force of gravitation is no man can say. Hence, the expression "vital force" was but a confession of ignorance. No, there is no such thing as a "vital force." There are in living Nature and in the inanimate world the same materials, ruled in both cases by the same natural chemical and physical laws, only the conditions in living Nature are different from the conditions in the inanimate, and consequently the phenomena observed are likewise different.
Let us now look at some of the discoveries which have caused us to accept this material view of life.
Harvey, in 1616, first taught the true doctrine regarding the circulation of the blood, and compared the heart to a pump.
Scheiner, a Jesuit priest, declared the action of the eye to be like that of a camera obscura, the lens of the eye acting to form a picture on a background.
Keppler developed the theory of spectacles.
Borelli explained how the mechanism of breathing was due to the elasticity of the lungs and to the muscles acting as power upon levers—the ribs.
Lavoisier showed that animal heat was due to the decomposition of higher chemical compounds of the food eaten, just as the heat of the candle is produced by the combustion of its constituents.
All these facts are easily seen to be but followings after Nature's laws. Chemistry brings many proofs confirming the doctrine that there is no fundamental difference whether of properties or of governing laws between the animate and the inaminate. The chemist turns starch into sugar in the laboratory; the intestines do the same.
We find at the beginning of this century a theory supported by Lavoisier which declared that, to form an organic compound, life was necessary. The organic compounds had properties essentially different from the inorganic or mineral, and were formed under different influences—under the influence of a "vital force."
The greatest blow to this theory was the discovery by Wöhler, in 1828, that he could make urea in the laboratory. Here, then, was a characteristic animal substance, which was actually formed in the laboratory without the intervention of any "vital force" whatever. Since Wöhler's discovery an overwhelming number of similar bodies have been formed in like manner. Sugar may be made from its elements—carbon, hydrogen, and oxygen. There is little doubt that at some future time the method of making all the materials of any organization will be known to the chemist.
It has been said that organic materials are more easily decomposable than inorganic; but albumen, if dried, will keep for years, whereas silver iodide on the sensitive photographic plate is changed by light in the hundred-thousandth part of a second.
Hence, it is not difference in materials that can distinguish the organized from the unorganized. Indeed, every organization consists in major part of water, which is inorganic, and every organization must contain salts. In both organic and inorganic we find crystals; white of egg, has already been crystallized. In fact, there is no boundary to be drawn. Over the organic and inorganic rule the same natural laws. The distinction is merely conventional.
The difference between the organized and the unorganized does not lie in the materials represented, only in the arrangement of the materials. The element of life is the minute cell. All life in the organization is dependent upon the activity of the cells. I have said that the conditions in the organized were different from those in the unorganized. The cell furnishes the conditions for life. Now, the arrangement of the materials in the cell is different from that in unorganized matter. In the piece of copper or crystal of sugar the smallest particles are everywhere the same. In the living organized cell the smallest particles are everywhere different. Such arrangement of materials that the conditions for life are present is the so-called protoplasm.
The yeast cell is a microscopic sausage-shaped organization which, under proper conditions, changes sugar into alcohol and carbonic acid. This is a characteristic function. In the same manner the cells in the body have their characteristic functions in decomposing the materials furnished by the blood. The living cell is made up of organic and inorganic constituents. It contains carbon, hydrogen, oxygen, nitrogen, sulphur, phosphorus, chlorine, sodium, potassium, calcium, magnesium, fluorine, silicon, and iron. All these are necessary to life. Abstraction of one of these elements means death to the organization.
We have traced life down to the cell. The lowest forms of life, both animal and vegetable, are single cells, and from these single cells, according to the theory of evolution, all life has been produced. But how about the origin of the first cell? We do not believe in spontaneous generation—that is to say, no case of the spontaneous generation of life from its elements has ever been recorded by man. But we may reason thus: All substances, even the simplest, require certain conditions for their production. The conditions required to produce a living cell must of necessity be extremely complicated. We do not know of such conditions, but for the sake of argument we may imagine that at some former period of the world's history conditions may have existed favorable to the production of the first life.
When we seek to define life we uncover a difficult problem. But who can define the steam engine? There is no satisfactory definition for either. We can merely say that life is the result of the activity of the cells.
It follows from this that it is useless to seek for a seat of life. The seat of life has been placed in the blood, but this is the nourishing fluid; in the heart, which is merely the pump for the blood; in the medulla oblongata, but this contains the nervous center for breathing. There is no such thing as a seat of life. Life is the result of the activity of all the organs of the body.
To every living thing there at last must come an end, and in this fact of death the advocates of a "vital force" saw the necessity for their theory. But this is explicable in a material manner. In life, as in death, decompositions are continually going on. These decompositions are in kind not different, only during life the products of decomposition are removed, and at death these products remain in the body and poison the individual cells—that is, so alter them that their conditions no longer fulfill the requirements of life.
The uneducated Indian when first shown a watch thought that it was alive; we, on the contrary, have come to regard the living organization as a machine. Upon this basis alone can physiology endure as a science, and physiology is, as the reader knows, nothing Init the study of the phenomena of life.
I have endeavored, up to this point, to give an exposition of the material view of life as complete as the most exacting materialist could desire. Many men reach this point and refuse to see further; they make materialism their creed, and cast religion to the winds. Now, is this rational? Is it impossible for the scientific mind to conceive of the existence of the soul? Certainly not.
When we seek for explanation of intellectual activity we find two views advanced—one, the purely material view that all thought comes uncontrolled from the decomposition of matter, from motion in the molecules; the other, the spiritual view that mental activity is under the domination of a soul. Under no circumstances can the soul be in a position to produce something out of nothing; it must rather, in the production of thought, utilize the materials furnished to the brain by the blood. The existence of the soul has never been scientifically proved; on the other hand, no material thinker can pretend that the purely material view explains the phenomena of intellectual activity. Let us see, therefore, if we can not employ some reasoning in support of the spiritual view, which declares the existence of the soul.
Matter is divided into ponderable and imponderable—ponderable, that which can be weighed; imponderable, that which can not be weighed. We place a body under the bell jar of an air pump and exhaust the air; all the ponderable air is thus removed. There still remains the imponderable ether. On this ether ligh-twaves travel, and the object in the vacuum therefore continues visible. Here, then, is a something in the vacuum which is invisible, imponderable, and yet whose existence is scientifically acknowledged as pervading all space. This ether is set in motion by the vibrating object we have under consideration; this motion is communicated to the nerve endings on the background of the eye, travels thence along the nerve, and produces in the visual sensorium of the brain the sensation of what we call light. The existence of this ether has never been scientifically proved, but it gives an explanation to something otherwise inexplicable.
A man dies; the spirit passes from him; the flesh is left. The man has not lost in weight; the spirit is imponderable. Now, as there is a connection between the luminiferous ether and the nerve endings for sight, why can not there be a connection between the spirit and the countless mass of cells and fibers where is what we call the intellect? And, likewise, may there not be a spiritual ether surrounding us, a medium through which impulses may come to the spirit from on high, and from the spirit be transmitted to the intellect? Such influences come to us strongly at times, as at the communion-table. The existence of the soul, I have said, has not been scientifically proved, but it is the explanation of something otherwise inexplicable.
We gain our experience of the world through our senses. Man is born with intellect, and through the senses that intellect is trained. The newborn baby possesses already some knowledge of touch acquired before birth, and this knowledge he afterward rapidly expands by constantly feeling his body over and over, as if in exploration of unknown territory. Later he acquires the faculties of hearing and seeing, and likewise of tasting and smelling. Now, these senses, five in number, are they which train the intellect. They are all very imperfect. Sight: but the greater part of the solar spectrum is invisible—that is to say, more rays which come to us from the sun are invisible than those which our eye can see. Hearing: but there are sounds so low and sounds so high that they are inaudible. Taste and smell: very imperfect. Touch: but there are millions of particles of dust to the square inch of the hand which we can not feel. Yet, even with these imperfect means of education, many men have reached the conclusion satisfactory to themselves that they are clever; but the wisest man knows nothing in comparison with perfect wisdom.
The whole of the known universe consists of matter in motion. All sensation, everything we know of the outside world, comes to us through motion. The motion sets up a movement in the nerve ending, on the skin, on the retina of the eye, or wherever the proper ending capable of receiving the particular motion may be situated. This motion is carried from the nerve ending along the nerve to the special central organ of the brain where it is interpreted. Light, sound, touch, taste, and smell are the only forms of motion we are capable of appreciating, because for each of these forms of motion we have a special apparatus which can receive, transmit, and interpret. There are other forms of motion which we can not appreciate—magnetism, for example—and this simply because we have no nervous mechanism which responds to that kind of motion. In like manner there can exist around us forces in infinite variety of which we have absolutely no knowledge whatsoever.
Now, is it not conceivable that, in the spirit after its severance from the flesh, our present imperfect senses may become perfect, and the influence of other now unthought-of sensations become possible? What the new sensations and the new life will be are unknown, unknowable. A man is born blind. He attains through touch, hearing, and the minor senses a certain amount of knowledge of the outside world, but his ideas of what really is must of necessity be absolutely and entirely different from our own. The operation for cataract is performed; the man can see, and is shown a familiar object—a book for example; but he can not say what it is; he must touch it first. His ideas of things undergo an immediate and radical change. So it will be at death with our ideas of heaven. The blind spirit, released from the influence of the flesh, passes into perfect understanding of infinite knowledge.
To my mind, the material view of life should have no terrors to believers in religion.