What I Believe and Why
As I have found it hard to believe that the activities of life can be fully explained by the laws of physics, altho life constantly uses the laws of physics, so I am not easily persuaded that mentality, with its crowning power of will, is explained under the laws of life. Such is the teaching of those who hold that thinking is nothing more than brain action. Beyond all question the brain is active in all mental processes; and one can make the hypothesis that the brain is all there is to it, that its province is to produce, secrete thought, feeling, will, consciousness, just as the liver secretes bile; or one can take another hypothesis that the brain is an instrument which is used in the production of mental activities by some separate, outside, immaterial power somewhat as a harp, inactive and silent itself, is the instrument of music, responsive to the fingering of the musician. In the latter view one could think of the brain either as responsive to the influence of some universal force, as the wind plays on an Aeolian harp, or as affected by the action of an individual mind attached to itself alone. That would be the man's soul, and this view has held the field the world over, and in all ages. This is mainly because the phenomenon of will is evidently the action of individual and not general consciousness. We know, if we know anything, that we feel, we think and we will, each for himself. We may then dismiss the supposition of some universal force blowing upon the brain, or, to use the figure of the ocean, bubbling up into it as producing all its activities, whether we call that force God or anything else. Under the hypothesis of some external power using the brain as instrument our consciousness puts it under the control of each individual's own mind, but may leave the question open whether other minds can also use it. We have then two alternatives left to consider, one that thought is entirely a function of the brain; the other that each brain has its own ruling mind, separate from matter, which uses the brain as its implement.
Brain and Soul
The physiologist cannot decide which of these two hypotheses is true. His business is to study the activities of the brain, and he may see nothing but the brain acting, while the psychologist may see something else.
The knife and the microscope can investigate only the material brain and discern how it works. If there is mind it is as invisible as the wind which we know blows on a harp. It might seem a hopeful method of further research to inquire whether the law of conservation of energy applies to mental action. Here we find that every thought or feeling or volition is accompanied by a certain action of the brain cells, and flow of blood, so that the brain is affected by every mental activity. Yet this is not conclusive; there may be something else. Even so the harp is affected in the movement of its strings and the vibration of its frame by the finger of the player, so that the amount of force in the finger is exactly matched by the energy of these vibrations. But it is the player that plays the tune, not the harp. In the case of the brain, however, it is impossible to prove that any Joule's law is applicable to the transformation of brain matter or brain force into an equivalent amount of thought-force. In his Presidential Address before the British Association in its physiology section, 1911, Prof. J. S. Macdonald says:
There is no one at the present time who is in a position to discuss the energy transformation of the central nervous system. Further, there is certainly no one capable of dealing with such peculiarities as might arise in the energy transformation of that part of the brain which is associated with the mind.
He further says:
There is no scientific evidence to support or to rebut the statement that the brain is possibly affected by influences other than those that reach it by the definite paths proceeding from the sense organs and from the different receptive surfaces of the body. It is still possible that the brain is an instrument traversed freely, as the ear by sound, by an unknown influence which finds resonance within it. Possibly, indeed, that the mind is a complex of such resonances, music for which the brain is no more than the instrument, individual because the music of a single harp, rational because of the orderly structure of the harp. Consider such a possibility ... inasmuch as an instrument shaped in the embryo of a certain set of conditions may in due course of time become the play of some new influence which has taken no immediate part in fashioning it. I will not dwell upon the point beyond this statement that I find it difficult to refrain from using the word soul.
Professor Macdonald's illustration appears to me to have argument in it. The ear is a delicate organ inactive and useless until mysteriously excited by a vibration from without. Just so the eye more delicately constructed must wait for the access of light before it can see; and even so it may be that the yet more delicate organism of the brain which is torpid in sleep or under anesthesia is an instrument which is traversed as freely as is the ear or the eye, by an exterior influence which finds resonance within it. That influence would be the soul.
Thinking Is Not Material
We see; but we do not see what it is that makes us see. We have sight and the organ of sight; but because we cannot see the cause of sight which affects the eye we assume and believe in an invisible ether and its invisible waves. We cannot see the cause which affects the brain and gives us thought, but we are quite within our rights when we assume that something works on and thru the brain, and we call it, invisible as it is, mind or soul. We have the right to believe that it is something more and other than brain because the brain is purely material, matter that has life in it, and its products must be material, as all products of living matter are, seeds, fruits, muscles, organs. Thinking is not material. It is very hard to conceive of thought as a function of matter, even of the brain, for we see in it nothing akin to material forces. Thought belongs to a different plane. It is immaterial, spiritual, not physical. What is a thought? Can you put it in balances and weigh it? Can you measure its bulk? Has it dimensions? By what yard-stick can we measure love and hate? By what micrometer can we compare the relative values of ideas? Conscience has no relation to weight or bulk. No physiologist can tell us that Shakespeare exhausted more brain-tissue in writing "The Tempest" than Walt Whitman in composing "Leaves of Grass," or that Virgil's brain was more worn away than that of Msevius.
Yet it is for another reason chiefly that the boor or the philosopher believes he has a soul, a proof that depends on consciousness. He feels that there is something in him that is lord of his body. He originates purpose, will, and his body serves and obeys him. He cannot think of the body as himself. He is its master; it is his slave. The master must be something other than the slave. He does not see it, and he thinks of it as something spiritual. It is then easy for the savage to imagine that in dreams his soul leaves the body and wanders off to visit other souls. The philosopher regards the dreams as mere fancies of imagination, but he knows that something in him, or, rather, the real self has initiative, originates thought, exercizes will, and using the reservoir of the brain sends messages by way of the nerves, which are but the extensions of the brain to all the body. To him the whole nervous system, brain as well as the spinal cord and the nerves, seems all to be but his instruments, the brain like the boiler of a locomotive from which power goes thru steam pipes and cylinders to move the pistons and wheels, while the engineer's will controls it. So I look at the operation of the mind and the body. The brain is the steam-chest, the blood is the furnace which supplies its force, the steam pipes are the nerves which carry the force where needed, and the remaining machinery corresponds to the parts of the body which obey the message of the nerves. But back of all is that which gives orders, which we call the soul, the engineer of the great human machine, which knows, thinks, wills, while brain and cord and nerves are its obedient servants. Man wills; he cannot think that matter wills. There is something of the same intangible order as is the will itself that he feels is ruler, originator, initiator, something more than the material body. If there is nothing beyond the working of the cerebrospinal nervous system, then, as it appears to me, there can be no freewill; all must go on mechanistically. But it does not go on mechanistically. "No physics, no mathematics," says Sir Oliver Lodge, "can calculate the orbit of a house-fly."
Such seems to me to be the reason why all except some philosophers have come to believe in the existence of a soul within, or related to, the body. It carries conviction to my mind, and I do not think it is because I and all other people wish to believe. I do not yet put any serious weight in the so-called psychic revelations. The evidence for them have not convinced me of their genuineness, and my incredulity is supported by their worthlessness.
What relation does belief in the immateriality of the human soul have with belief in God? Just this, that the existence of many millions of human souls, all immaterial, all invisible, does away with any presumption against the existence of a superior, or supreme, immaterial, invisible Being related to the universe which he may control, even as the human soul controls its body. The argument is not absolute and final; one can yet disbelieve. The step is easy, however, from the human soul to the existence of a Soul of the Universe, which yet is not the universe, but which rules over it as the human soul rules the body.