At the Edge of Science

In universities where they are taught, there are two subjects which are usually combined into one department: the history of science and the philosophy of science; and they can make strange bedfellows. The history of science, reconstructing the problems with which great men of science of the past were confronted, and paying due attention to the state of knowledge then attained, studies the way in which they solved those problems, if necessary repeating the observations and the experiments which they made. Such studies can be as objective as the work that they retrace; in a sense they are verifications of old data, and can qualify as science.

With the philosophy of science, the situation can be different. One distinguished leader in this field has said that scientific observations and experiments do not really tell us anything about the universe, but only suggest to us how to draw a picture of the universe. The trouble with this is that it lets the door wide open to considerations which are not scientific but subjective. This is how there has come to be a Roman Catholic philosophy of science, of which Galileo once fell foul, which placed Montesquieu’s and Erasmus Darwin’s works on the Index of prohibited books, and which has still not reconciled itself to facts of human ecology. On the other side there has arisen a Marxist history of science in the name of which Nicolai Ivanovitch Vavilov was murdered and a whole science—genetics—for a time stifled. These are some of the reasons why scientists are suspicious of the philosophy of science, for since the conclusions to which it comes can rarely be subjected to experimental tests, it may be philosophy but may also not be science.

And yet the problem cannot be shrugged off easily. However hardheaded and objective the scientist may be in the laboratory, the time always comes when he must make sense of his results. In any scientific discipline, say chemistry, it is usually the case that the data can be arranged in the framework of more than one hypothesis. Eventually, if he is lucky, the scientist decides on one of these hypotheses in preference to the others. Was the reason why he preferred that hypothesis to the others a chemical reason? No; it was because, in his view, it accorded with more data than did the others, and encountered fewer obstacles. In other words, it seemed to him to approximate more closely to, to what? We must avoid saying “to the truth,” because that may involve a moral judgment, but we can say, to the accurate description of whatever phenomenon of nature was being studied. This preference for refinement of accuracy is not itself chemical; nor was the preference for the Copernican as opposed to the Ptolemaic system itself astronomical; nor is the preference for the theory of evolution by natural selection of heritable variation, over the mysticism of special creation, itself biological. What has come in here is a sense of values, not in themselves scientific, which is basic to all intellectual activity. This, I suppose, is philosophy; and it must have been the reason why Sir Winston Churchill once said at the Massachusetts Institute of Technology: “How right you are to have a Dean of Humanities.” Philosophy as the servant of objective science; not a flying horse for metaphysical speculation.

THESE PROLEGOMENA have been introduced so as to try to come to some conclusion about which shelf in the library the book under review belongs to. I may be accused of cowardice when I suggest that there should be two copies of it: one in general philosophy, and the other in the history of science, and I expect a ton of bricks from the protagonists of the philosophy of science who will claim that this book rightly belongs to them.

It is learned, well-constructed, finegrained, and closely argued, yet eminently readable. It sets out to place the genealogies of ideas, treated in the authors’ previous volumes, into their historical contexts, and to generalize about the interchange between scientific thought and “culture.” By “discovery of time” is meant the addition of this dimension to those of space in attempts to interpret the universe; and this implies the intrusion of what is called “history” into studies of the universe.

The authors claim to have made two discoveries. The first is that there has been a close parallel in the growth of historical consciousness across a whole range of subjects as widely separated as physical cosmology and theology or sociology, a conclusion which shows how they have found themselves led to step off limits from the natural sciences into other fields of intellectual inquiry that are usually separated from science, such as the humanities. The second relates to the recurrence of patterns of theory in a number of disciplines (they call them “historical sciences”) which have faced common forms of problems with similar methods of solving them, such as the establishment of well-founded temporal sequences of past epochs. With all this on the plate, I fear that a really adequate review of such a book is barely possible without going some way toward answering the Chinese examination paper which has only one question: comment on all you know.

The pageant advances majestically from the speculations of the Greeks, through myths, the Scriptures and their heavy hand, the Renaissance, the emergence of natural science, the philosophes, and the geologists, to Darwin who forced a pedigree on life with consequences to human thought which have still not been squarely faced, let alone fully fathomed. Throughout, the treatment is objective, and neither politicians nor theologians will find much grist for their mills in it. I have found only one point in it which I know to be incorrect, and I shall describe it, if only in order to show how high the standard of the authors’ accuracy is. Jean-Etienne Guettard was the first, in 1751, to recognize the volcanic nature of rocks in the center of France, and the discovery was important because it clipped the wings of the “Neptunists” who attributed everything in the Earth’s crust to the effects of Noah’s Flood. Guettard was accompanied on this memorable journey from Paris, through Vichy, to Volvic, by Chrétien-Guillaume de Lamoignon de Malesherbes that great statesman who was afterwards guillotined for having served as defense counsel to Louis XVI. But Guettard was a man who made enemies; his work was denigrated, his priority denied, and a curious story gained credence (also with the present authors) that it was on his return from Vesuvius (where he never went), going up the Rhône at Montélimar, that his attention was drawn to the volcanic nature of rocks by the paving blocks in the roadway. In itself, this false story has not the slightest importance, except to provide an example of how error can be grafted in the place of truth and incorporated in “history” (see Annals of Science, vol. 18, 1962, p. 49, for details of this little story). Such mistakes can be serious, however, as when Friedrich Wöhler is credited (but not by these authors) with having synthetized urea in 1828, and broken down the barrier between inorganic and organic chemistry. It was no synthesis but a decomposition, for Wöhler started from blood, horns, and hooves, and made no claim to have broken a barrier, only to have obtained urea without a kidney, musing on the fact that it was necessary to start from materials taken from a living organism (see D. MacKie, Nature, London, vol. 153, 1944, p. 608).

PERHAPS THE MOST INTERESTING but intractable problems raised in the mind of the reader of this book relate to the meaning of the words “history” and “historical sciences.” The authors quote R. G. Collingwood’s definition that only human beings, not nature, have history, because the historian is concerned with the motives of the people who have played a part in the events which are called history. On this view, cosmology, geology, and biology cannot qualify as “historical” sciences. To this, the authors point out that human and non-human history share certain methods of inquiry, and that their common features are more significant than their differences. They claim for example that archaeology plays a large part in history, and that archaeological methods cannot be sharply distinguished from those of geology. I wonder, particularly when I see Sir Isaiah Berlin writing (Historical Inevitability, Oxford, 1954, p. 52):

History is not identical with imaginative literature, but it is certainly no more free from what, in a natural science, would rightly be condemned as unwarrantably subjective or personal. Except on the assumption that history must deal with human beings purely as material objects in space—must, in short, be behaviorist—its method can scarcely be assimilated to the standards of an exact natural science. The invocation to historians to suppress even that minimal degree of psychological evaluation which is necessarily involved in viewing human beings as creatures with purposes and motives (and not merely as causal factors in the procession of events), seems to me to rest upon a confusion of the aims and methods of the humane studies with those of natural science. It is one of the greatest and most destructive fallacies of the last hundred years.

Arising out of this problem is another, which has recently been treated by George Gaylord Simpson as “the historical factor in science” (This View of Life, New York, 1964). Starting from the definition of history as “change through time,” Simpson has no difficulty in showing that it is inadequate. A chemical reaction in a test-tube results in change through time, but is not a historical event such as was Newton’s observation of the fall of an apple. The chemical reaction has always occurred and will always occur; Newton’s observation was non-recurrent, it was the result of previous events in Newton’s life and the cause of other events in the lives of Newton’s successors. The chemical reaction is non-historical, Newton’s observation was historical. Non-historical events are immanent in the material universe; historical events are configurational. The fascinating thing is that a science such as biology can contain both non-historical and historical components. Molecular biology is immanent and non-historical; palaeontology is configurational and historical. This distinction has bearings of the highest importance on the great principles of uniformitarianism, predictability, emergence of new properties, and extrapolation of trends.

SO THERE ARE NON-HISTORICAL sciences and historical sciences, and both types occur, though to different extents, in the various branches of science as traditionally defined. In the spectrum starting from physics and passing through chemistry, astronomy, geology, biology, anthropology, psychology, and sociology, the historical element is least in physics and greatest in sociology (which is why it is not universally accepted as a science). Nevertheless it would be incorrect to conclade that non-historical sciences are concerned solely with immanent properties, and historical sciences only with configurations, because “explanation” in the historical sciences includes all the relevant facts of the non-historical sciences involved. Biological evolution includes the immanent items of atomic and molecular properties.

This is some measure of the depths of the waters through which the authors of the present book navigate with skill and grace. They stimulate, too.

As ethology improves our understanding of animal behavior, we may acquire something of the same insight into the outraged feelings of territorial possession that set the Roman geese cackling on the Capitoline Hill. Human motives, after all, are not entirely unique. Thus, in the last resort, what marks human history off from natural history is the fact that it is—quite deliberately—man-centered. The motives of the Capitoline geese are interesting to the Roman historian only for their effect on the human city: we can leave the geese themselves to write their own goose-history.

But was it their innate sense of territory that set the geese cackling, and not sheer funk at unusual noises? It would be interesting to devise an experiment to test not only how intense is a goose’s sense of territorial possession, but also what the stimuli are to which it responds by cackling. But this is science, and it suggests one last problem which crosses the mind of at least one reader of this book: We have had a definition of history, and we have seen that there are non-historical sciences and historical sciences. What, then, is science itself?

SCIENCE, IN ENGLISH, for the last hundred years has meant the natural sciences, and this limitation must be due to the fact that the material benefits conferred by applications of physics, chemistry, biology, and medicine, to men’s lives on the material plane have been greater than the uncertain advantages that have accrued from theology, history, or philosophy. John Ruskin struggled hard to resist this limitation of the word science, and in 1875 he argued that “there is a science of Morals, a science of History, a science of Grammar, a science of Music, and a science of Painting; and all these are quite beyond comparison higher fields for human intellect, and require accuracies of intenser observation, than either chemistry, electricity, or geology” (Works, vol. 22, p. 396, London, 1906). Poor Ruskin, the worst advocate possible for achieving his object.

Just as mistaken as Ruskin are those who think that science can be defined in terms of what they call “the scientific method” of observation and experiment, which scientists use, and which have given such outstandingly successful results. So they have, but they can be and are also used in epigraphy, palaeography, numismatics, bibliography, genealogy, and linguistics. Even philately can benefit; after the philatelist has brought observation to bear on the stamp which is the object of his study, he performs an experiment, by applying alcohol to the back of his stamp to reveal its otherwise invisible watermark. The so-called “scientific method” is not restricted to “science,” which has no monopoly of it.

What, then, is science? Karl Popper has called it the field of intellectual endeavor in which propositions can be disproved but never proved, a conclusion to which he has said that he came when contemplating the fact that Newton’s system was overtaken and displaced by Einstein’s. Such an asymmetrical concept of the confidence to be attached to hypotheses is no doubt useful, but it makes one wonder whether the tragedy of a beautiful theory killed by an ugly fact is really so general in the progress of science. Science progresses by refinement, rather than by revolution, but this has still not yet told us what science is. Simpson has defined it as an exploration of the universe that seeks natural and orderly relationships among observed phenomena, and that is self-testing. May we add that it is the result of application of the so-called “scientific method” to the products of nature, the only material out of which this method can extract general principles of universal validity? The watermark on a stamp may establish a fact, but no general principle.

It has become fashionable, but I believe misguided, to refer to intellectual activity in western civilization as split between two so-called cultures. In fact, the culture that has blossomed in western civilization is so rich that it has spread into a much larger number of streams than two, among which, unfortunately, the exigencies of education have not provided the opportunities for interchange and cross-fertilization which are desirable. But in the liberal arts as in the sciences, the mental processes are the same, and so is the use of imagination. Already William Whewell saw, over a hundred years ago, that the elemental or generative act in scientific discovery is an idea, the consequences of which can then be tested. Newton’s extension of the force pulling the apple to the earth to the force preventing the moon from flying off at a tangent was an idea. Darwin’s principle of natural selection was an idea. Mendel’s system of segregation and recombination of particulate hereditary factors was an idea. And this leads straight back to the book under review which is, above all, a notable contribution to the History of Ideas.

I am well aware that I have not answered the Chinese examination paper; I don’t know all the answers, and that is why I have preferred to write about the problems and the questions which this book raises.