Mr. Koestler and the Astronomers

The Golden Blade, 1960, pp 94-103

Before a man can take off a pair of tinted spectacles, he must first discover that he is wearing them. He can then remove them and, in doing so, may learn for the first time that it was they and not his eyes which were making the world look all that one peculiar colour. After that he can put them on and off at will.

One of the significant changes now going on around us is that more and more people are beginning, very slowly and tentatively, to look not only with, but at the so-called scientific outlook – ‘so-called’ because what is ordinarily meant when ‘science’ is referred to is in fact a particular philosophical theory. This theory is beginning dimly and doubtfully to take objective shape in our minds as an historical phenomenon. I do not know if it was Sir Herbert Butterfield who coined the phrase “the Scientific Revolution” in his book The Origins of Modern Science, published in 1949, or if it was in use before that. It is at all events one which we meet with more and more often today; and it is one which is frequently employed by the author of a book, with an Introduction by Sir Herbert and the formidable sub-title “A History of Man’s Changing Vision of the Universe,” which appeared in the early part of 1959 and met with an immediate and enthusiastic response.

Arthur Koestler, the well-known author of Darkness at Noon and The Yogi and the Commissar, started his career as a student of science in Vienna, and was at one time science editor of a chain of newspapers in Germany. When he gave up political writing in 1954, he began work on this book, The Sleepwalkers,1 which is intended, he says, to contribute toward “the ending of the cold war between the humanities and science.”

“The dilemma of our time,” his publishers add on the dust-cover, “is rooted in the split between science and religion,” and the purpose of the book is,

by an inquiry into the obscure workings of the creative mind and an analysis of the changing relations between scientific and religious insight, to find out whether mankind may yet hope to find a new unified line of thought – a way of escape from our present impasse.

The purpose of this article is to examine, in some detail, the quality, scope and value of the book, and, in the course of doing so, to consider how far the publisher’s claim is justified.


The Sleepwalkers is a substantial work of 624 pages, of which about 80 are devoted to notes, bibliography and index. A surprising feature is the high proportion of space given to biographies of two or three leading astronomers: Copernicus gets a hundred pages, Kepler nearly two hundred, and we are even given a brief account of their ancestors and collaterals; so that we close the book with the feeling, on the whole, of having been engaged in a biographical rather than a philosophical or scientific voyage of discovery. Koestler has his reasons for this. He is interested, not only in the results, but in the psychological process of discovery. “The progress of Science,” he writes in the Preface,

is generally regarded as a kind of clean, rational advance along a straight ascending line: in fact it has followed a zig-zag course, at times almost more bewildering than the evolution of political thought. The history of cosmic theories, in particular, may without exaggeration be called a history of collective obsessions and controlled schizophrenias; and the manner in which some of the most important individual discoveries were arrived at reminds one more of a sleepwalker’s performance than an electronic brain’s.

If, even so, the quantity of biographical material makes the book somewhat lopsided, having regard to the sub-title and the declared predominant purpose, I should hesitate to stigmatise those parts as blemishes. In dealing with the history of thought, there is something healthy about an attempt to take into account the whole man instead of isolating the workings of his cerebellum. It tends for one thing to advance us beyond the prevailing contemporary notion that the history of thought is a purely dialectical drama, towards the concept of an evolution of the thinking-process itself; and few things are more necessary than that such an advance should now be made.

Moreover, the biographies are extremely well done. One hardly knows whether more to admire the accumulation of industrious research which underlies them or the skill and lightness of touch with which the hoard is exploited. Whether he is retailing the vagaries of “the timid Canon,” Canon Koppernigk (known to the learned world as Copernicus) and his uncle Lucas, the Bishop, or the melancholy boyhood of Johannes Kepler, or the latter’s peculiar method later on of choosing a wife, or again, the artificial gold-and-silver tip of Tycho Brahe’s nose, which he frequently rubbed “with some ointment or glutinous composition”, Koestler does it all with a verve and gusto which make it prodigiously readable. An outstanding merit of the book is the smooth way in which it passes from anecdote to history to astronomical and physical theory, and from these back again to anecdote. One thing or another – the easy-going, unpretentious English in which it is all written flows equably on. Occasionally, it is true, it falters. Narrative stride degenerates into pedestrian cliché when Kepler is patronisingly referred to as “our hero,” and gusto disappears in vulgarity each time his mother (who was once nearly burned as a witch) figures jocularly and pointlessly as ‘Ma Kepler.’

These lapses into literary nudging and thumb-jerkings are of no particular significance, though they are unworthy, so long as they are confined to the anecdotal parts of the book. It is a different matter when we find them spilling over into the scientific and philosophical passages; as when after briefly referring to the Aristotelian and medieval conception of the moon’s orbit as the boundary between the earthly and the celestial realms, the author finds it necessary to add:

The space enclosed by the sphere of the moon and containing the earth – the “sub-lunary region” – is now definitely considered non-U.

The sporadic occurrence of such consciously contemporary facetiae indicates a fundamental lack of sympathy with the past which stands in the way of that very historical imagination which “our author” nevertheless makes outstanding efforts to exert. It is one of the minor marks of just that ‘hindsight’ (the projection back on to the past of a sophistication subsequently acquired) against which he more than once goes out of his way to warn the reader; and we find in fact that Koestler over-estimates the degree to which he has succeeded in entering into the mental processes of mankind before the Scientific Revolution.

Curiously enough, he over-estimates it even quantitatively, seeming to think that he has devoted much more attention than he has to the relation between the scientific and other approaches to the nature of reality. Thus he tells us on page 426 that “one of the points I have laboured in this book is the unitary source of the mystical and scientific modes of experience; and the disastrous results of their separation”; but in actual fact it is very difficult to find a single passage in which this unitary source is explicitly referred to, let alone ‘laboured.’


The book begins with a brief account of pre-Socratic – and particularly Pythagorean – Greek philosophy. Pythagoras is warmly praised, and an interesting and not unsympathetic account is given of the Pythagorean attitude to the mystery of number. But for Koestler this “Pythagorean dream of musical harmony governing the motion of the stars” was important mainly because it fore-shadowed modern mathematics and the Scientific Revolution. Religion and science are also said to have “met” in the relation between Orphic and Dionysian cults, and one would have thought that here, if anywhere, was an opportunity to say something about the source of mystical experience, if Koestler wished to do so. But no:

The cult of Dionysus-Bacchus, the “raging” goat-god of fertility and wine, spread from barbaric Thracis into Greece. The initial success of Bacchism was probably due to the general sense of frustration which Xenophanes so eloquently expressed. The Olympian Pantheon had come to resemble an assembly of wax-works, whose formalised worship could no more satisfy truly religious needs than the pantheism – the “polite atheism” as it has been called – of the Ionian sages. A spiritual void tends to create emotional outbreaks; the Bacchae of Euripedes, frenzied worshippers of the horned god, appear as the forerunners of the medieval tarantula dancers, the bright young things of the roaring twenties, the maenads of the Hitler Youth…

If Dionysus and the labouring of unitary sources are the order of the day, compare this bit of twentieth-century animistic anthropology, laced with conventional twentieth-century psychology, with, let us, say, Nietzsche’s Birth of Tragedy!

We find the same sort of ‘hindsight,’ when Koestler touches on Plato. All that Plato meditated and taught on the relation between Being and Becoming, the Permanent and the Changing, the whole great symphony of the later Dialogues, is cheerfully assigned to “an unconscious yearning for stability and permanence in a crumbling world where ‘change’ can only be a change for the worse and ‘progress’ can only mean progress toward disaster.” It was, moreover, “Plato’s loathing for change – for ‘generation and decay’ – which made the sub-lunary sphere such a disreputable slum-district of the universe.” This may be Russell on Plato, or even (for we are assured that Plato hated the artisan class) Marx on Plato. It is of course not Plato – nor even a touch of him.

After this we do not expect, and we do not get, a particularly sympathetic sketch of St. Augustine and the City of God. (“The Rectangular Universe”) or of the “Dark Interlude” of the eleven or twelve centuries which followed. It is with the sixteenth century and the entry of Copernicus on the stage, as the book begins at last to deal with thinkers whom the authors knows at first-hand and not by hearsay – and knows, I should surmise, about as well as any man now living – that The Sleepwalkers really gets into its stride.

Skilfully interwoven with the racy biographical yarns to which I have already referred, we find ourselves absorbing almost without effort a clear, cool and corrective account both of the genesis of the famous Copernican theory and of the theory itself. Copernicus did not teach that the sun is at the centre of the solar system. He supposed that it is near the centre both of the solar system and of the universe, but that the earth and the planets revolve in perfectly circular orbits round an empty point in space. Nor was his system an improvement on the Ptolemaic system from the point of view of geometrical simplicity. If Ptolemy required forty epicycles in order to “save the appearances,” Copernicus needed forty-eight! Nor did he come into collision with the Church. Copernicus had an unbounded respect for the ancients and is described by Koestler as “the last of the Aristotelians.”

The real astronomical issue in the Scientific Revolution, the really vital change in men’s thinking about the heavenly bodies, was not the change from a geocentric to a heliocentric system, or the assumed rotation of the earth about its own axis. Both these ideas had been put forward in pre-Christian times. What was entirely new, and fraught with such momentous consequences, was the dawning notion that, in forming hypotheses about the nature and motions of the heavenly bodies, it is proper to bring in the physical laws which are found by bodily experience to apply to objects on earth.2 For this way of looking at things carried in its womb the modern assumption that the ‘laws’ by which we calculate the motions of the heavenly bodies are not merely geometrical devices, to help us with those calculations, but are an actual description of the reality. From then on the starry heavens gradually ceased to be a visible representation of a purely spiritual source, in which the origin of physical earth and physical man must be sought; for they were themselves physical. New heavens, in fact, were very like old earth writ large. It was this metamorphosis, combined with the heliocentric hypothesis, which led to the modern ‘speck of dust’ fixation and Pascals’s “Le silence éternel de ces espaces infinis m’effraie.”

In the age of Copernicus, ‘gravity’ was still a synonym for ‘weight,’ and the notion that the heavenly bodies possessed a quality which could properly be called ‘weight’ was conceived and born in the mind of man only with enormous difficulty. Kepler was the first to explain ‘weight’ as the mutual attraction between two bodies, and it was Kepler who, with the utmost reluctance, first abandoned the assumption of circular orbits for the planets and introduced the ellipse. One of the best things in the book is its account of the haphazard way in which Kepler hit on these two notions, while he was searching for something totally different – namely an explanation of the relative distances of the planets from the sun. He had formed the theory that these could be found constructing concentric spheres proportioned to each other in such a way that one of the five Platonic solids could be exactly inserted between each pair. It was in pursuit of the same quest – which in the end he had to abandon – that he arrived quite empirically at his third law: that the squares of the periods of revolution of any two planets are as the cubes of their respective distances from the sun. Yet the three laws, which Kepler discovered in this surprising way, are “the pillars on which Newton built the modern universe.”

In the first edition of the Mysterium Cosmographicum, Kepler had spoken of the “souls” of the sun and of the planets and raised the question whether “the souls which move the planets are the less active the farther the planet is removed from the sun, or there exists only one moving soul in the centre of the sun…” In the second edition he suggested, in a note on this passage, that the word “force” should be substituted for the word “soul” and added:

Once I firmly believed that the motive force of a planet was a soul. … Yet as I reflected that this cause of motion diminishes in proportion to distance from the sun, I came to the conclusion that this force must be something substantial – “substantial” not in the literal sense but … in the same manner as we say that light is something substantial, meaning by this an unsubstantial entity emanating from a substantial body.

It is worth quoting at length Koestler’s comment on all this. “We are witnessing,” he says,

the hesitant emergence of the modern concepts of “forces” and “radiating energies” which are both material and non-material, and, generally speaking, as ambiguous and bewildering as the mystical concepts which they have come to replace. As we watch the working of the mind of Kepler (or Paracelsus, Gilbert, Descartes) we are made to realise the fallacy of the belief that, at some point between the Renaissance and the Enlightenment, man shook off the “superstitions of medieval religion” like a puppy getting our of the water, and started on the bright new road of Science. Inside those minds we find no abrupt break with the past, but a gradual transformation of the symbols of their cosmic experience – from anima motrix into vis motrix, moving spirits into moving force, mythological imagery intro mathematical hieroglyphics – a transformation which never was and, one hopes, never will be entirely completed.

The above is one of a number of isolated passages scattered throughout the book – most of them shorter, and many of them no longer than a sentence – which make it difficult not to believe that the author has true historical imagination and with it a real sense of the evolution of human thinking as distinct from a supposed purely dialectical “progress” of ideas. It is odd that the effect of the book as a whole should be to make it equally difficult to believe that he has. In the passage quoted he describes as a fallacy the belief that the advancement of science is simply the shaking off of illusion and superstition. But elsewhere that is just how he appears to think of it. It would be difficult, he says, to over-estimate “the revolutionary significance” of this new notion of “forces” instead of “souls” and the assignment of physical causes to celestial phenomena. Yet he never seems really to have opened his imagination to the universe as it stood before that revolution. Why does he write of Pythagoras and his followers with such deep respect – and then by way of contrast present Aristotle to us as a kind of scientific zombie, with a capacity for “terrifying verbal acrobacy” and “a highbrow system of animism”? In my opinion because, in spite of the Preface and the Epilogue, and the scattered passages to which I have alluded, and after carefully tracing the origin of the startlingly new concept of a celestial physics, Koestler still assumes at the bottom of his thinking that this very concept was there in men’s minds from the beginning.

Thus the “revolution” turns out to have been after all something more like a revival of learning. It was really only a return from Aristotle to Pythagoras. The Pythagoreans, we are told, had not only described heavenly motions in geometrical terms, but had assigned them a physical cause. Is this true? Where, then does the mystery of number come in? Koestler has never asked himself, it seems, whether the word ‘physical’ may not have so altered its meaning since (and because of) the Scientific Revolution  as to render its use quite inadmissible in connection with the philosopher who founded all on the harmony of numbers and the music of the spheres.

This element of what we might perhaps term “subconscious hindsight” is equally apparent in his scattered allusions to that principle of “saving the appearances,” which played such an important part in the speculations of astronomers from the time of Simplicius in the sixth century A.D. down to and including Copernicus:

The original meaning of this curious phrase was that a theory must do justice to the observed phenomena, or ‘appearances’; in plain words, that it must agree with the facts. But gradually the phrase came to means something different. The astronomer ‘saved’ the phenomena if he succeeded in inventing a hypothesis which resolved the irregular  motions of the planets along irregularly shaped orbits into regular motions along circular orbits – regardless whether the hypothesis was true or not. Astronomy, after Aristotle, becomes an abstract sky-geometry, divorced from physical reality. Its principle task is to explain away the scandal of non-circular motions in the sky.

The italics are mine. But suppose that Aristotle did not experience phænomena – appearances – in the same way that we do. Suppose that before the Scientific Revolution there was a fundamental difference between the meaning of ‘phænomenon’ (appearing) and the meaning of what we call ‘fact’! It then becomes unnecessary to invent a change of meaning for the phrase, for which , as far as I know, there is no evidence.

Now Koestler himself speaks in his Epilogue of “a new innocence of perceptions liberated from the cataract of accepted beliefs.” He appears therefore to be aware that what is taken for granted in the act of perceiving becomes part of the perception. Does it not follow from this that, just as we perceive the absence, so the man of the Middle Ages and his predecessors perceived the presence in the universe of a noumenal or spiritual reality, of which the phenomena of heaven or earth were essentially images? Unless this is conceded, it is impossible to enter with any sort of sympathy or understanding into the astounding tenacity with which practically all astronomers from Pythagoras to Copernicus insisted on presuming that the only real motion of any celestial body must be that motion in a perfect circle which Plato in the Timæus described as “having the most to do with the mind and thinking”. We are reduced, instead, to the lame device or the defence-mechanism, of making fun of it. But there is no space to go further into this aspect of the matter, which I have endeavoured to consider in my book, Saving the Appearances.


Koestler calls his book The Sleepwalkers; yet he never seems to have considered the significance of actual sleep, and the dreams that go with it, for man’s relation to the Universe, nor the veridical element in imagery as such and in the apprehension of nature as image. If he were to take into acount – to give a random example – the ‘universal symbols’ of which Dr. Erich Fromm has written in his book The Forgotten Language and to consider what bearing they have or had on the possible meaning to others than ourselves of the word ‘appearances,’ he would be able to remove a good many irregularities from his own cosmos, without the help of awkward philosophical or speculative ‘epicycles’. He would, for instance, no longer find it necessary to explain, or fail to explain, Aristarchus of Samos and his heliocentric hypothesis as a “paradox,” to write of the philosopher whose thinking dominated the civilised world for 2,000 years as a clever, self-deceiving word-spinner, and to diagnose the entire intellectual life of the Middle Ages as the product of “double-think” and schizophrenia.

To admit that nature may be validly apprehended as imagery will be found to involve admitting a supersensible link between the mind of man and the wisdom immanent in the universe; whereas Koestler’s “creative mind” is no more than the personal intelligence in each man’s head, “creating” an empty reflection of a universe from which it is quite shut out. Any idea that the mind of man, whether sleeping or waking, is part of the structure of the universe, and that therefore the universe itself has changed with man’s idea of it – this is as remote from his approach as it has always been from the “positive” philosophy which has distorted the Scientific Revolution and arrogated to itself the name of “science”.

Some members of the Anthroposophical Movement are inclined to think that the progress of scientific enquiry along its present course will of itself lead to a crossing of this difficult “threshold” out of positivism and into a participating knowledge. Others feel that there must first be an abrupt break, and a right-about-turn away from spectrum and cloud-chamber, from genes and particles, and into the Goethean method, which is based on the development of man’s powers of perception and their application in the exact and imaginative observation of phenomena on the macroscopic, that is the human, scale. They doubt whether such a volte face can ever come about except as the result of a new beginning, based on the spiritual science to which Rudolf Steiner has sown the way.

Whichever view is taken, the appearance of The Sleepwalkers, and its reception by the reviewers, would appear to be a portent of some significance. Its very inconsistencies and the unstable equilibrium of its standpoint make it so.

I have already referred briefly to some of these inconsistencies, and many more examples could be picked out. Thus, on the one hand it is said to be a fallacy (see the comments on Kepler quoted above) to believe that after the Renaissance men shook off the superstitions of medieval religion; there was no abrupt break with the past. On the other hand, Ptolemaic astronomy was “a monstrous system … which strikes us today as an affront to human intelligence”. But on the other hand again, our own present-day notion of “a ball of fire hurtling across the sky through eternity, without burning out”, is itself “a preposterous idea at which the mind boggles”. The teaching of Pythagoras is in one context serious and important; in another it is obliquely alluded to as “hocus pocus”. And the doctrine of “saving the appearances”, when it appears in Osiander’s famous Preface to Copernicus’s De Revolutionibus Orbium Cœlestium, is ascribed to the “timid Canon’s” timidity and guyed mercilessly:

The Copernican revolution entered through the back door of history, preceded by the apologetic remark: ‘Please don’t take it seriously – it is all meant for fun, for mathematicians only, and highly improbable indeed.’

Yet when it reappears in the Epilogue (described now, for some reason, as “Urban VIII’s famous argument”), it is treated by the author himself with the deepest respect, and we are admonished that:

If there is a lesson in our story, it is that the manipulation, according to strictly self-consistent rules, of a set of symbols representing one single aspect of the phenomena may produce correct, verifiable predictions, and yet completely ignore all other aspects whose ensemble constitutes reality.

Well – and is not the whole self-consistent apparatus of physical laws and explanations “one single aspect”?

Readers of Ovid’s Metamorphoses will recall that he is apt to describe the actual process of metamorphosis in unexpected detail, so that we get disconcerting and even ludicrous moments in which someone is half a human being and half a bird or a tree – with arms perhaps of flesh and blood terminating in twigs and leaves instead of fingers. In something the same way the author of The Sleepwalkers seems partly to have emerged from the contemporary scientific world-view and to be looking at it from outside with a cool, appraising glance, and partly to be still nestling within as snugly as any Encyclopædist or philosophe of the Enlightenment, or as the late H. G. Wells, forever rapping cloth-headed antiquity on the knuckles with the tartness of an exasperated pedagogue. Now one thing, now the contradictory other, the ensemble does really suggest an ungainly, hobbledehoy sort of moment in the emergence of a later stage in some life-process out of an earlier one that has not yet been discarded.

Or so it may appear to a future generation, if the former of the two views about the future of science turns out to be correct and science is reaching a point at which it will undergo a fairly smooth metamorphosis. But if the other view is correct, and there has to be something like a breakdown before the threshold can be crossed out of the impasse towards which its ingrained positivism is steadily forcing it, the book will still, I think, be seen as a significant landmark. For this is not a case of yet one more detached and philosophic mind coming to realise that the ice of scientific assumptions is getting too thin to bear. What makes it significant is just that the author is not a retired philosopher, but a busy journalist and political novelist, plunged up to his neck in “the cataract of accepted beliefs”. What is so striking is that certain loud and ominous cracks should be coming audible even to someone who has not seen the Warning Notice and is still energetically skating.

All this is not to say that the book is valuable only as a symptom. Far from it. How much easier it is to criticise than to write one! How much this one gives to us in its own special way of historical understanding and appreciation, of intimate personal acquaintance with the protagonists, of unfamiliar facts skilfully marshalled and entertainingly presented! We have had to conclude that it does not by any means do what is claimed for it; but how very much it does do which no one else has ever done, which no one else could have done, which no one else will ever do again with just that peculiar emphasis and in that genial style!

Owen Barfield

1 Hutchinson. Return.

2 We are brought up to take this for granted and therefore think nothing of it. It is however a pure hypothesis and must remains so unless and until a human being is actually lobbed on to one of the planets to prove it on his muscles. Meanwhile an innocent glance at the night-sky should be enough to convince anyone that, until we did get used to it, it was a very startling hypothesis indeed. Return.

Copyright © 1997 — Owen Barfield Literary Estate.       Return to Top.