Stars, Proteins, and Nations

by PHILIPPE LE CORBEILLER

1

WHEN nowadays people find themselves discussing our economic, social, or international difficulties, someone is sure to say: What’s really wrong with us is that science has got ahead of morals. We know too much about atoms and too little about ourselves. We should call a halt, a moratorium on science, and give mankind a chance to learn the Golden Rule again.

At the same time, the Marxists tell us: Physical sciences have developed to excess because there was profit in them for the capitalist and the entrepreneur. A classless society would develop the biological sciences instead and would further the welfare of the people.

Both groups apparently take for granted that mankind has up till now developed physics, chemistry, and engineering by preference, and that it could today take up biology or psychology if it wanted to, much as a man decides to drop tennis and take up golf. Both groups are wrong. Physics and chemistry have developed ahead of the other sciences because they are simpler. There is a definite order in which sciences have developed in the past and are likely to develop in the future.

This century-old idea has not won much currency, but it throws a good deal of light upon the t roubled conditions of our times. Suppose we examine it.

The originator of the idea was the French philosopher, Auguste Comte, whose first great work, Positive Philosophy, was published in the eighteenthirties. In this work Comte first makes a list of the fundamental sciences, and suggests placing them in line in such a way that each science should be dependent upon those preceding, and independent of those which follow. Comte’s classification was later improved on by Herbert Spencer, and Spencer’s list runs thus: Mathematics, Physics, Chemistry, Biology, Psychology, and Sociology.

A glance at this list is enough to show that it actually fulfills the required condition. Mathematics can be and often is presented without any reference to the material world. Physics (including its mother science astronomy) makes use of mathematics, but we are careful to eliminate from a physical experiment any chemical transformation. Chemistry uses heat and electricity, but on principle precludes the intervention of living organisms. Biology makes use of physics and chemistry; psychology presupposes living individuals; and sociology deals with these individuals acting as members of a group. If we run down the list, the successive sciences become more complicated, but more interesting to the average man, and more essential to his daily life; if we go through the list backwards, the sciences become simpler in subject, but at the cost of becoming more and more abstract.

It is already an achievement to have placed the various sciences in such logical order. But this list is also valid from quite another point of view, that of historical development. As Comte expressly observes, although the different sciences are now developing simultaneously and side by side, any one is actually older and, at a given time, more advanced than the one which follows it on the list.

Mathematics was carried by the Greeks to a point of development far ahead of that of physics and chemistry. Algebra was reborn in the sixteenth century. Only a hundred years later, calculus was invented, but physics was still in its infancy. At the end of the eighteenth century, calculus had reached marvelous heights, the mighty edifice of Newtonian astronomy had been raised, elementary physics was well constituted (but electromagnetism was as yet unsuspected), and chemistry was just beginning. Modern biology got under way about the middle of the nineteenth century, roughly at the time electromagnetism culminated in 'the work of Maxwell; and psychology was born towards the end of the century. It is remarkable that the historical rule pointed out by Comte should still hold good today after more than one hundred years of intense and unpredictable development. It looks as if Comte had laid his finger upon some really fundamental law in the evolution of mankind.

It may seem arbitrary to say glibly that biology is today less advanced lhan physics. Are there not about as many courses in biology as in physics in a university, and does not a student of biology have to learn just as many facts as a student of physics? Is not the literature of biology comparable in extent to the literature of physics?

All this of course is true. To understand in what sense we mean that physics and chemistry are more advanced than biology, let us look more closely at these two groups of sciences.

2

CONSIDER the first chapter of physics, which is mechanics, and the fundamental law of dynamics that force is equal to mass times acceleration (Newton’s second law). None of these three terms represents anything visible or tangible — anything, in fact, which may be observed directly. “Force” and “mass” have here technical meanings far removed from those they have in everyday speech. “Acceleration” is the “rate of change of the rate of change of a displacement,” surely not something to be found in nature, but a devilishly complicated and artificial invention of man. Anyone who would suggest using three such arbitrary and abstract concepts in order to explain the flight of a ball would be thought completely crazy. But, lo and behold, it has worked. A law has been found to hold between the indications of the instruments which measure force, mass, and acceleration, and this law, suitably generalized, describes, as we now know, the course of planets in the heavens, of a shell on its trajectory, and of electrons in a radio tube. Its field of application is as broad as the whole universe.

What is true of this fundamental example is true throughout the realm of the physical and chemical sciences. We do not perceive a piece of temperature or a bit of heat; we only feel hot or cold. Physicists invented the scientific concepts of temperature and of quantity of heat, which were afterwards found to be connected by laws. They also invented the concepts of electric tension and current, and the volt and the ampere— but here they did much more than invent the concepts: they actually created the phenomena. There is surprisingly little electricity in nature. Imagine how many million times a day a man-made voltage or current is being measured and compare it with how many times a year a man is hit by lightning or shocked by an electric eel. One might almost say that before the eighteeneighties, the globe was not electrified.

Similarly, mere observation could never have “discovered” silicon or aluminum, although sand and clay are common enough. Like most chemical elements, they exist in nature only in combination. Pure elements were extracted from their natural combinations by the chemists in the laboratories, following the lead of earlier experiments and theories. And it has often been remarked that without man’s industry the greater part of the millions of compounds synthetized in organic chemistry would never have seen the light of day.

As we have seen in the case of Newton’s law, the justification for inventing all these physical and chemical concepts is that they could be connected by numerical laws. We know of no law connecting a magnetic lodestone and a piece of amber; but a numerical law does connect a magnetic field, an electric current, a velocity, and a force, all of them abstract man-made concepts. This specific law has been verified innumerable times in the past; and a physicist will bet you anything that it will again be verified, to a specified approximation, if you and he together put it to the test.

For such is the astounding character of most physical or chemical laws — in fact, of all quantitative laws: a quantitative law is a numerical prediction. If I tell you, for instance, that mixing 36.5 grams of hydrochloric acid with 40 grams of soda produces 58.5 grams of common salt and 18 grams of water, the meaning of this statement is that whenever you perform this experiment, the next hour, the next day, the next month, in any case in the future, you will get exactly those amounts of salt and water—to an approximation depending mainly upon the purity of your materials.

If the logical meaning of a quantitative law consists in its being a prediction, the role of science in the creation of modern industry rests on precisely the same basis. The ancient craftsman made pottery, swords, and dyes according to traditional rules which he could not understand. He had no way of measuring the temperature of his kiln or the purity of his materials; hence the ever present element of luck in the quality and appearance of his products, as well as his appeal to magic. In presentday industry the quality of the product, whether electrical power or a certain type of steel, a specific synthetic dye or a pharmaceutical product, is quantitatively predicted within specified and narrow limits.

Now one of the solidly established traditional beliefs is that man cannot read the future. That is why, in all civilizations, if a “prophet” can persuade a few people that he predicts the future, then for them he is a man of God or else has magical powers: as an ordinary man, he could not read the future. Science, however, predicts the future accurately — in a domain, to be sure, rather restricted, but constantly enlarging. This ability is truly revolutionary and has never happened before our times. This aspect of science is rarely stressed, because those who live in a technical environment, whether a chemical laboratory or a steel mill, take it for granted, and other people are barely aware of it.

Consider now the biological sciences. The more traditional ones, such as anatomy or zoology, consist of collecting and correlating all that naturalists have been able to learn from the observation of living beings as they fall directly under observation. This is in striking contrast with physics and chemistry, which deal with intellectual, abstract, manmade concepts.

A good part of the biological sciences is still at the observational stage. Of course this is the right way to start: physics and chemistry also started at the observational stage. Even now, every time a new physical phenomenon is noticed — X-rays, radioactivity, cosmic rays — physicists also begin by observing it as if it were a strange animal, noting how uranium salts spoil photographic plates, or wondering how deep cosmic rays penetrate under the sea, and so forth.

After the observational stage of science comes the experimental stage. A great part of our biological knowledge, most physiology in particular, results from experiments on living organisms. In the last century such experiments consisted in abstracting some organ, or submitting the plant or animal to some unusual environment or diet, and noting the result.

This type of experiment is now becoming more and more refined. Physical stimuli can be specified with the sharpness and numerical precision common in physics. The “response,” which in classical examples was death, or at least some gross disturbance, now consists of a change in some specific biological function, measured on a numerical scale. In the most successful cases a hypothesis can be proposed, leading to a mathematical formula compatible with the observed data. Later, by modification of the original experiment, one will attempt to check the correctness of the hypothetical guess. The science of biophysics, although as yet in its infancy, is obviously here transforming a chapter of biology into a quantitative and conceptual science of the physicochemical type.

Other experiments consist in trying out the effects of some chemical substance. The chemical agents which are of interest to biology are of a highly complicated nature; all the resources of organic chemistry are used to aid in ascertaining the specified chemical compound which will produce a sharply defined and minute functional effect. This auxiliary role of chemistry has naturally developed into the systematic investigation of the chemical processes which go on in living matter. Biochemistry is a growing science which has gone far towards explaining the functional role of individual parts in a correlated organism. The advance of pharmacology, bringing synthetized drugs to the remotest country doctor, is one of its practical counterparts.

Another branch of biology uncommonly fascinating, even for the layman, is genetics. Genetics is a new science which was developed very much on the pattern of physics. Time after time, in order to understand some observed phenomenon, a theory was invented, dealing with imagined and at that time unobservable concepts, and the mathematical or logical consequences of this assumed theory were checked against experience. It is no wonder that this procedure aroused the most bitter and heated criticism from the older authorities.

Yet the progress of our knowledge of cells has proved more than once that what was meant by geneticists to be nothing but a helpful hypothesis was in fact a shrewd guess about very minute particles of a germ cell which were actually there. Here we have a parallel with the history of the atomic hypothesis in physics; and similarly the chemists have been amazed to learn that the hexagonal carbon ring which they used symbolically in their formulas was actually visible in an X-ray pattern. Thus does biology, in biophysics, in biochemistry, in genetics, gradually adopt the ways of the older physical sciences.

3

THESE specialties, however, are but the vanguard of the advancing forces of biology. The major part of that science, as a glance at any standard textbook will show, is as yet frankly descriptive. The contrast with the deductive sciences of physics and chemistry is apparent in the old and moot question of the synthesis of life. For scientific knowledge automatically brings forth man-made construction, or synthesis. When man succeeded in finding the laws of vapors, he made steam engines; when he understood electricity, he made induction motors and radios; when he understood chemistry, he made aluminum pans and synthetized aspirin.

Why can’t we synthetize living beings? For one thing, are we sure we have not already synthetized one of some sort? Give a little child a watch to hold. He recognizes at once, if you do not, that he is holding something alive in his hands. When a man makes a motor pump, he is in fact building a mechanical heart. A locomotive or a car goes one better: the pumping of its heart makes its wheels turn, and it advances on a road under its own power. In Victorian discussions of “What Is Life?” locomotion was always listed among the mysterious achievements attained by animals only. In recent years this contention has been quietly dropped: the retort has become too obvious.

Nowadays regulation is sometimes presented as another of these unaccountable marvels exhibited by living organisms. We find in more and more cases that the minute amount of a specific substance normally contained in some organic liquid or tissue is maintained within narrow limits by two antagonistic systems, one of which boosts up the required percentage when it is too low, and the other reduces it when it is too high. Death may follow the breakdown of either system. But velocity regulators or “governors,” the first form of which was invented by Watt at. the end of the eighteenth century, began to be well understood a hundred years later, and in a modem plant every important physical or chemical quantity (temperature, voltage, concentration) is automatically regulated.

What is more, regulation is now but the first step in the technique of servomechanisms, which was raised during this last war to such uncanny heights and which connects, for instance, a hundred-ton gun turret to a searching radar in the way the arm of a tennis player is connected to the motion of his eyeballs.

It is not the actual construction of a watch, governor, or servo which is of value to biology, but the fact that we now understand thoroughly the dynamical relationships which are essential to the maintenance of oscillations, the regulation of a physical variable, or the control of a motor by a sensory organ. From this angle as well as from several others, such as the mechanics of cellular structure, the understanding of the physical side of life has made ‘considerable strides. It has resulted in the construction of man-made models, exhibiting one after another of the physical functions which were once considered to be characteristic of living organisms.

On the chemical side, the way ahead is also mapped out. The simplest and least differentiated living organisms are made of protein. Now protein is the generic name for a group of chemical substances of a most complex nature. A protein is a linkage of a very great number of simpler chemical groups, such as amino acids, which we know well, but we know very little as yet about how this linkage is made. We still do not know what a protein is; that is to say, we do not understand its properties, which is the same thing, and we cannot synthetize it, which is saying the same thing over again.

The situation was exactly the same with regard to rubber twenty years ago. Latex was a substance made by a certain tree, and its chemical nature was not understood. Chemists succeeded in synthetizing (understanding the constitution of) rubber ten years or so ago, and because of war pressure the question has been so well cleared up that half a dozen different kinds of artificial rubber with different properties are now manufactured on an industrial scale. Chemists tell us that the synthesis of protein, barring surprises, is not exactly around the corner; they appreciate the difficulties better than non-chemists can. But we may be sure they will once more succeed, in a not too distant future.

By underlining the role of physics and chemistry in the advance of biology, I may have given the impression that I am advocating the view, quite popular in the last century, that biology is at bottom nothing but physics and chemistry. There can be no doubt, on the contrary, that since we do not at all understand several of the most important functions of living organisms, our understanding them will depend upon concepts which lie beyond those which we arc using at present. What I have been saying is that it is no wonder we do not understand life, since physics and chemistry have not yet advanced to the point where they can provide biology with the proper physical and chemical basis.

What scientific concepts biology will later invent to supplement those of physics and chemistry we of course do not know; we begin to have a bare inkling that they may have to do with organization. The elasticity of rubber has recently been linked mathematically with its fully developed chemical formula. There is no telling what the complexities of the protein formula will really mean in terms of the properties of living protoplasm. This is a very crude hint at concepts as yet unborn.

Electromagnetism may give us an idea of how biology will some day blossom out above physics and chemistry. Electricity and magnetism were also very mysterious at first. Familiarity with the industrial effects of electric power has robbed us of the sense of awe which we ought to feel when we see, for instance, an electromagnet attracting a dozen steel rails and carrying them through the air without any mechanical hold. It took a century to develop the proper concepts for coping with these eerie facts and linking them together in what is known as Maxwell’s equations. Now that the task is done, we see that electromagnetism cannot be deduced from mechanics alone; its laws are broader and contain the Newtonian laws of mechanics as a specific case.

In this way, those who declared electricity to be nothing but mechanics have been proved wrong, while those who insisted that the same scientific method which had mastered dynamics, optics, heat, and so forth, would also master electricity have been proved right. The history of science does not repeat itself any more than does the history of nations, but, like the history of nations, it can provide patterns which may help us to recognize similarities and to orient our thought.

4

IN OUR classification of sciences, after Mathematics, Physics, Chemistry, and Biology comes Psychology. It comes after them because a large amount of physiology is independent of so-called mental processes, whereas thought, or at any rate consciousness, seems an attribute of living beings provided with a nervous system and is dependent upon physiological conditions. Therefore psychology cannot be expected to reach the scientific stage (the stage at which physics and chemistry are at present) until some time after biology itself has reached it.

Indeed, if we look at present-day psychology, we find that its major branches have existed only since quite recent times. Physiological psychology was founded in Germany in the second half of the last century, but its beginnings look extremely crude when compared with the extensive, deep, and delicate type of research which is carried on nowadays, particularly in America. This type of work is so interesting and hopeful that obviously psychologists are here making only the preliminary exploration of an immense and unknown territory. The particular study of behavior inaugurated by Pavlov was the discovery of another, totally different continent of thought. Psychoanalysis, originated by Freud in 1900, has completely revolutionized our outlook on the everyday conduct of man, as is apparent not only in professional work but even more strikingly in the popular books and magazine articles aimed at the general public.

In the case of the three divisions of psychology which we have just named, as well as in a few others, one gets the following double impression. First, one is amazed at the childishness of psychological writing prior to these new discoveries; second, one gets a definite feeling that since such essential and unrelated points of view were completely unsuspected so short a time ago, it is certain that many other equally essential aspects of psychology will have to be discovered before mankind gets even a rough idea of the ext ent of this science, let alone begins its scientific exploration. The growing understanding of the intimate relationship of mind and body — how a certain chronic illness, for instance, is accompanied by a certain mental attitude and vice versa — and the realization of how little advanced biology actually is, make it obvious that psychology as a science is barely born.

On this basis one might expect the social sciences to be entirely in the faraway future. And as a matter of fact, by far the greater part of sociology is at the purely descriptive stage: it studies types of society, existing or historic, as the naturalists of the seventeenth century described existing plants or animals. Some writers even remind one of the medieval naturalists, wishfully imagining societies about as plausible as hippogriffs and unicorns. It is remarkable, however, that a few of the social sciences (those which make systematic use of some science coming earlier in the classification) have risen above the descriptive stage and have begun working with abstract concepts. In economics, a group of mathematically trained researchers has been doing extremely promising work during the last decades, using the method of analytical dynamics in the study of economic systems.

In a totally different field, the application of psychoanalytic findings to anthropology and history has done much to explain such social facts as totemism and taboos, or the birth of the scientific spirit in the Ionian colonies of ancient Greece.

Such use of abstract concepts is of course disparaged by the conservative mind. It will be a long, long time before sociology receives from biology and psychology its necessary foundations.

5

THE idea that the logical dependence of the successive sciences implies a necessary order in their historical development is thus found to be entirely correct when we compare their various present states. In every science the scientists do their best towards advancing their particular field; but it is entirely outside their power to raise their subject suddenly to the level of those which precede it in logical order. They are like workmen building and furnishing a house: the plumbers and electricians cannot begin to work until the walls are in place; the plasterers come next, then the painters, and last the furniture movers.

The fact that biology, for instance, does not, in general, use the same approach as physics and chemistry, and has not yet succeeded in synthetizing a living organism, is usually explained or excused on the ground that living organisms are essentially different in nature from dead matter. Similarly the science of mind is said by some to be of an altogether different kind from the science of nature. I believe that this is taking a much too modest view of these sciences. The further along they are placed in our classification, the more complex and inclusive their subject; and therefore it is necessary that the simpler and earlier sciences should have progressed effectively before biological, then psychological and social, problems may be tackled in a truly scientific fashion. But these sciences will be eventually as rigorous and therefore as powerful as physics and chemistry are today.

In the meantime there are urgent everyday problems to be solved, which cannot, wait until all the factors involved are scientifically known. An example we are all too familiar with is illness. A child is dangerously ill; the physician is acutely conscious of the fact that biology and psychology do not provide him, as chemistry does the chemist, with an infallible rule of action. He calls to his aid, in addition to all the scientific knowledge he can muster, the best conclusions he can draw from insecure analogies, and the even less reliable support of intuition. He will make use of anything to save that child. This is why medicine is still called by many an art, not a science, and physicians find in the moral responsibilities they incur one of the highest marks and the true glory of their profession.

The case of engineering is somewhat similar. Techniques in general are a mixture of the scientifically known and the scientifically unknown. In metallurgy, for example, we know the physics of heat and the chemistry of iron and of carbon, but there is a great deal we do not know about what is called the physics of solids. Still, the engineer cannot wait another hundred years before building a steel bridge. He uses empirical figures and multiplies some of them, such as the velocity of the strongest winds in the region, by a “factor of safety" of 2, 3, or more, to be, as he thinks, on the safe side. Yet it happens sometimes that such unscientifically obtained figures turn out to be too small, and the bridge breaks down. Techniques, medicine, government, are all solving urgent problems the best they can, without waiting for the unfolding of scientific progress in its Comtian order of battle.

If all sciences are not today at the “scientific” level, which they will, one after another, reach some day, there is a broader sense in which the workers in the different fields can rightly be called scientific. Among the rules followed in physical research, some are purely technical, and refer, for instance, to the proper handling of a precision balance or spectroscope; some refer to the relative functions of hypothesis, calculation, and experiment; and the rest are of an ethical character. They demand of the research worker an extreme scrupulousness in noting down the conditions and results of his experiments; a complete absence of prejudice and a high degree of self-criticism in comparing the theory that is being checked with the recorded observations; and complete sincerity in his reports.

The successes of physics and chemistry have been so spectacular that, in every field, workers have wanted to avail themselves of the same method; and if it is not yet possible in every science to apply mathematical tools to quantitative laws, it is always possible at any rate to follow the same ethical rules. Thus a historian rightly considers himself scientific when he reports on firsthand historical data with the same scrupulousness, sincerity, self-criticism, and absence of prejudice as the physicist uses in reporting on his columns of figures. It is in this sense that the different sciences may be worthy of the name, irrespective of the state of advancement which they have reached at the present time.

6

IN the preceding pages, I have tried to present to the reader my sense of the obviousness of Comte’s logical and historical classification. Perhaps a few words should be added here, lest this hierarchy of sciences be taken too strictly and too rigidly.

In theory every science but sociology is an abstraction. Physics is what remains when everything chemical, biological, psychological, and sociological has been eliminated or ignored — and so on down the line. In practice no such rigid separation is usually possible, and most techniques borrow from several of the theoretical sciences.

For that very reason, all sciences will in a distant future eventually merge into one, a sort of sociology which will have absorbed all the natural sciences. From whatever point of view we look at the world, the oneness of nature impresses itself upon us. It is remarkable that already in our day physics and chemistry should have merged to a very large extent.

The road to this eventual unification is, however, the development of the sciences in the hierarchic order given by Comte, which I have tried to justify in the preceding pages. Let us draw some consequences from this position.

It would be far better to improve the organization of society than to build faster planes or better radios. But it would be of no avail to close physical laboratories and to substitute social laboratories, even if such a thing were at all possible. Only by continuing on the road along which successively appeared mathematics, astronomy, physics, and chemistry will mankind eventually solve its problems.

Some sciences, we have seen, are already at the quantitative and predictive level; others have reached it partially or not at all. We may call “science in the stricter sense” any coordinated group of quantitative laws; and “science in the broader sense ” any body of knowledge obtained according to ethical rules such as those I have mentioned. The latter meaning would apply to such sciences as history, philology, and semantics, as well as to sociology proper or economics. With this distinction in mind, we may say that physics, chemistry, and a small part of biology are today sciences in the stricter sense; while most of biology, an even greater portion of psychology, and the sciences of society as a whole are sciences in the broader sense only. We confidently expect biology to pass from the second group to the first in a not too distant future. Biophysics and biochemistry are in a way the pivotal sciences of our age. From their progress the most spectacular changes can be expected.

This does not mean that the next advances in psychology and sociology should be considered less important. These sciences are so much more closely tied up with our everyday life that, were it not absurd here to talk in numbers, one might say that one unit of advance in psychology or sociology is likely to affect us as much as ten units of advance in physics, or fifty in mathematics. But for psychology we cannot soon expect the kind of revolution which we foresee for the science of biology in the near future.

To say all that precedes in still another way; Greece, the later medieval period, and the classical period, had an unbounded faith in human reason. They thought man could solve any problem immediately by applying his reason to it.

We see now that this confidence was exaggerated. Contrary to what people think, we cannot solve sociological problems today by even the keenest reasoning. Reason can work only from secure premises, and the necessary premises to sociology, which are psychological, have not yet been obtained. If Comte’s classification really expresses logical and historical truth, then we must say that in our age, only problems in physics and chemistry are certain of solution, because only such problems are amenable to science in the strict sense. Most biological problems are not yet within the reach of the quantitative instrument forged by reason, but they will become so before too long. To solve psychological and sociological problems, mankind will have to progress another few centuries.