Scope and Limit of Scientific Materialism

by John Tyndall

(Posted November 13, 1998 · Issue 42)

Editor's note: This excerpt from an essay by the influential nineteenth-century physicist John Tyndall serves to remind us how little some fundamental questions change. Tyndall elucidates the materialist view of the formation of matter by "molecular force" into all its configurations, both inorganic and organic, and asserts that "in the eyes of science the animal body is just as much a product of molecular force" as an ear of corn or a crystal of salt - and as knowable: "The difficulty is not with the quality of the problem, but with its complexity; and this difficulty might be met by the simple expansion of the faculties which we now possess." But, then as now, our understanding is brought up short when we try to comprehend the connection between the physical brain and our thoughts, emotions, and consciousness. As Tyndall notes, this issue is of a different "quality," and while research continues to expand our faculties regarding the structure and workings of the brain, that essential enigma - how several pounds of gray matter and some electricity are linked to our joys and sorrows, and to our very sense of self - remains a mystery.

You see, I am not mincing matters, but avowing nakedly what many scientific thinkers more or less distinctively believe. The formation of a crystal, a plant, or an animal is, in their eyes, a purely mechanical problem, which differs from the problems of ordinary mechanics in the smallness of the masses and the complexity of the processes involved. Here you have one half of our dual truth; let us now glance at the other half. Associated with this wonderful mechanism of the animal body, we have phenomena no less certain than those of physics, but between which and the mechanism we discern no necessary connection. A man, for example, can say I feel, I think, I love; but how does consciousness infuse itself into the problem? The human brain is said to be the organ of thought and feeling; when we are hurt, the brain feels it; when we ponder, it is the brain that thinks; when our passions or affections are excited, it is through the instrumentality of the brain. Let us endeavor to be a little more precise here. I hardly imagine that there exists a profound scientific thinker, who has reflected upon the subject, unwilling to admit the extreme probability of the hypothesis that, for every fact of Consciousness, whether in the domain of sense, of thought, or of emotion, a certain definite molecular condition is set up in the brain; who does not hold this relation of physics to consciousness to be invariable, so that, given the state of the brain, the corresponding thought or feeling might be inferred; or, given the thought or feeling, the corresponding state of the brain might be inferred.

But how inferred? It is at bottom not a case of logical inference at all, but of empirical association. You may reply that many of the inferences of science are of this character; the inference, for example, that an electric current of a given direction will deflect a magnetic needle in a definite way; but the cases differ in this, that the passage from the current to the needle, if not demonstrable, is thinkable, and that we entertain no doubt as to the final mechanical solution of the problem. But the passage from the physics of the brain to the corresponding facts of consciousness is unthinkable. Granted that a definite thought and a definite molecular action in the brain occur simultaneously; we do not possess the intellectual organ, nor apparently any rudiment of the organ, which would enable us to pass, by a process of reasoning, from the one to the other. They appear together, but we do not know why. Were our minds and senses so expanded, strengthened, and illuminated as to enable us to see and feel the very molecules of the brain; were we capable of following all their motions, all their groupings, all their electric discharges, if such there be; and were we intimately acquainted with the corresponding states of thought and feeling, we should be as far as ever from the solution of the problem, "How are these physical processes connected with the facts of consciousness?" The chasm between the two classes of phenomena would still remain intellectually impassable. Let the consciousness of love, for example, be associated with a right-handed spiral motion of the molecules of the brain, and the consciousness of hate with a left-handed spiral motion. We should then know, when we love, that the motion is in one direction, and when we hate, that the motion is in the other; but the Why? would remain as unanswerable as before.

In affirming that the growth of the body is mechanical, and that thought, as exercised by us, has its correlative in the physics of the brain, I think the position of the "Materialist" is stated, as far as that position is a tenable one. I think the materialist will be able finally to maintain this position against all attacks; but I do not think, in the present condition of the human mind, that he can pass beyond this position. I do not think he is entitled to say that his molecular groupings and his molecular motions explain everything. In reality, they explain nothing. The utmost he can affirm is the association of two classes of phenomena, of whose real bond of union he is in absolute ignorance.

John Tyndall (1820-1893) was born in County Carlow, Ireland. He was professor of natural philosophy at the Royal Institution, London, where he was a colleague and friend of Michael Faraday. His pioneering research included studies of light refraction and air particulates; he was the first scientist to explain why the sky is blue, and in experiments with purified air, he helped to disprove the concept of spontaneous generation.

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Endlinks

See these related HMS Beagle articles (and their links) for much more on neuroscience and the brain:

• Neurosciences on the Internet - review of the Web site.
• Splitting the Brain - an essay exploring current work with split-brain patients.
• How Brains Think: Evolving Intelligence, Then and Now - an essay on the evolution of intelligence.
• Brains and Hurricanes: Highlights of the 1997 Society for Neuroscience Meeting - a brief review of the 1997 Society for Neuroscience Meeting.
• A Unified Theory of the Brain - a short excerpt from Peter Pan.