IV THE PRACTICE OF REASON IN PHYSICAL SCIENCE
Although we know that reason is attached to perceptible matter, to physical objects, so that science can never be anything else but the science of the physical, still we may, according to the prevailing ideas and usage of language, separate physics from logic and ethics, and thus distinguish them as different forms of science. The problem is then to demonstrate that in physics as well as in logic, as also in ethics, the general or intellectual perceptions can be practically obtained only on the basis of concrete perceptible facts.
This practice of reason, to generate thought from matter, to arrive at understanding by sense perceptions, to produce the general out of the concrete, has been universally accepted in physical investigation, but only in practice. The inductive method is employed, and one is aware of this fact, but it is not understood that the nature of inductive science is the nature of science in general, of reason. The process of thought is misunderstood. Physical science lacks the theory of understanding and for this reason often falls out of its practical step. The faculty of thought is still an unknown, mysterious, mystical being for natural science. Either it confounds the function with the organ, the mind with the brain, as do the materialists, or it thinks with the idealists that the faculty of thought is an imperceptible object outside of its field. We see modern investigators marching toward their goal with firm and uniform steps, so far as physical matters are concerned. But they aimlessly grope around in the abstract relations of these things. The inductive method has been practically adopted by natural science and its successes have secured a great reputation for it. On the other hand, the speculative method has become discredited by its failures. There is, however, no conscious understanding of these various methods of thought. We see the men of physical research, when they are outside of their special field, offer lawyer-like speculations in lieu of scientific facts. While they arrive at the special truths of their chosen fields by sense perceptions, they still pretend to derive speculative truths out of the depths of their own minds.
Listen to the following statements of Alexander von Humboldt, which he makes in the initial argument of his "Cosmos" in regard to speculation: "The most important result of physical research by sense perception is this: that it finds the element of unity in a multitude of forms; that it grasps all the individual manifestations offered by the discoveries of recent times, carefully scrutinizes and distinguishes them; yet does not succumb under their mass; that it fulfills the sublime mission of the human being, of understanding the nature of things which is hidden under the cover of phenomena. In this way our aim reaches beyond the narrow limits of the senses, and we may succeed in grasping the nature by controlling the raw material of empirical observation through ideas. In my observations of the scientific treatment of general cosmic phenomena, I am not deriving unity out of a few fundamental principles found by speculative reason. My work is the expression of a thoughtful observation of empirical phenomena seen as one and the same nature. I am not going to venture into a field which is foreign to me. What I call physical cosmology does not, therefore, aspire to the rank of a rational science of nature.... True to the character of my former occupation and writings, which were devoted to experiments, measurements, and investigations of facts, I confine myself in this work to empirical observations. It is the only ground on which I can move with a measure of security." In the same breath Humboldt says that "without the earnest desire for the knowledge of concrete facts any great and universal world philosophy would be merely a castle in the air" and in another place that "an understanding of the universe by speculative and introspective reason would represent a still more sublime aim" than understanding by empirical thought. And on page 68 of volume I. he says: "I am far from finding fault with endeavors of others the success of which still remains in doubt, when I have had no practical experience with them."
Now natural science shares with Humboldt the consciousness that the practice of reason in physical research consists exclusively in "perceiving the element of unity in a multitude of forms." But on the other hand, though it does not always admit its belief in speculative introspection as frankly as Humboldt does, it nevertheless proves that it does not fully understand the practice of science and that it believes in a metaphysical as well as a physical science by using the speculative method in the treatment of so-called philosophical topics, in which the element of unity is supposed to be discovered by introspective reason instead of an analysis of multiform sense perceptions, and it demonstrates its lack of unity by being unaware of the unscientific character of disagreements, by believing in a metaphysical science outside of the physical domain. The relations between phenomenon and its nature, cause and effect, matter and force, substance and spirit, are certainly physical ones. But what is there of unity that science teaches about them? Plainly then, the work of science, like that of the farmer, has so far been done only practically, but not scientifically, not with a predetermination of success. Understanding, that is to say the practice of understanding, is well applied in science, I readily admit. But the instrument of this understanding, the faculty of thought, is misunderstood. We find that natural science, instead of applying this faculty scientifically, simply experiments with it. What is the reason for this? Natural science has neglected the critique of reason, the theory of science, logic.
Just as the handle and the blade of a knife constitute its general content, so we found that the general content of reason was the universal, the general "itself." We know that it does not produce this content out of itself, but out of given objects, and these objects are the sum of all natural or physical things. The object of reason is, therefore, an infinite, unlimited, absolute quantity. This infinite quantity manifests itself in finite quantities. In the treatment of relatively small quantities of nature the true essence of reason, the true method of understanding, is well recognized. It remains to be demonstrated that the great relations of the world, the treatment of which is still doubtful, are likewise intelligible by the same method. Cause and effect, mind and matter, matter and force, are such great world problems, and they are of a physical character. We shall demonstrate that the most general distinction between reason and its object furnishes the key to the solution of the great world problems.
(a) Cause and Effect.
"The nature of natural history," says F. W. Bessell, "lies in the fact that it does not consider phenomena as facts in themselves, but looks for their causes. The knowledge of nature is thus reduced to the minimum number of facts." But the causes of the phenomena of nature had been investigated even before the age of natural history. The characteristic mark of natural history is not so much that it investigates causes, but that the causes which it investigates have a peculiar nature and a particular quality.
Inductive science has materially changed the conception of causes. It has retained the term, but uses it in a different sense from that employed by speculation. The naturalist conceives of causes differently within his special field and outside of it; here, outside of his specialty, he frequently indulges in introspective speculation, because he understands science and its cause in a concrete, but not in a general way. The unscientific forces are of a supernatural make-up, they are transcendental spirits, gods, forces, little and big goblins. The original conception of causes is an anthropomorphic one. In a state of inexperience, man measures the objective by a subjective standard, judges the world by himself. Just as he creates things with conscious intent, so he attributes to nature his human manner, imagines the existence of an external and creative cause of the phenomena of sense perception, similar to himself who is the special cause of his own creations. This subjective mood is to blame for the fact that the struggle for objective understanding has so long been in vain. The unscientifically conceived cause is a speculation of the a priori kind.
If the term understanding is retained for subjective understanding, then objective science differs from it in that such a science penetrates to the causes of its objects not by faith or introspective speculation, but by experience and induction, not a priori, but a posteriori. Natural science looks for causes not outside or back of nature's phenomena, but within or by means of them. Modern research seeks no external creator of causes, but rather the immanent system, the method or general mode of the various phenomena as they are given by succession in time. The unscientifically conceived cause is a "thing in itself," a little god who generates his effects independently and hides behind them. The scientific conception of causes, on the other hand, looks only for the theory of effects, the general element of phenomena. To investigate a cause means then to generalize a variety of phenomena, to arrange the multiplicity of experienced facts under one scientific rule. "The knowledge of nature is thus reduced to the minimum number of facts."