(A) Classical geocentric system (B) "Egyptian" system of Herakleides
(C) System of Tycho de Brahe (and of Herakleides?) (D) Aristarchus' heliocentric system.
= Sun; = Moon; E = Earth; f = Mercury; g = Venus; h = Mars; F = Jupiter; G = Saturn
But model A could never be made to work properly. To our hind-sight, the reason is obvious: the planets were arranged in the wrong order; the sun should be in the centre, and the earth should take the sun's place between the "lower" and "upper" planets, taking the moon with her (Fig. D). This basic fault in the model caused incomprehensible irregularities in the apparent motions of the planets.
By the time of Herakleides, these irregularities had become the principal worry of the philosophers concerned with the universe. The sun and moon seemed to move in a more or less regular manner along the traffic lane; but the five planets travelled in a most erratic way. A planet would amble for a while along the lane, in the general direction of the traffic, West to East; but at intervals he would slow down, come to a stop as if he had reached a station in the sky, and retrace his steps; then change his mind again, turn round and resume his wandering in the original direction. Venus behaved even more capriciously. The pronounced periodical changes in her brightness and size seemed to indicate that she alternately approached and receded from us, and this suggested that she did not really move in a circle round the earth, but along some unthinkable, wavy line. Moreover, both she and Mercury, the second inner planet, now raced ahead of the steadily moving sun, now fell behind, but always stuck close to him, like dolphins playing around a ship. Accordingly, Venus at times appeared as Phosphoros the "morning star", rising with the sun in her wake, at other times as Hesperos the "evening star" at the sun's tail; Pythagoras seems to have been the first to recognize that they were one and the same planet.
Once more, in the rear-view mirror, Herakleides' solution of the puzzle seems simple enough. If Venus moved in an irregular manner relative to the earth, the supposed centre of her orbit, yet danced attendance to the sun, then she obviously was attached to the sun, and not to the earth: she was a satellite of the sun. And since Mercury behaved in the same manner, both inner planets must revolve round the sun – and with the sun round the earth, like a wheel turning on a wheel.
Figure B on page 46 explains at a single glance why Venus alternately approaches and recedes from the earth; why she is at times ahead of, at others behind, the sun; and also why she intermittently moves in reverse gear along the Zodiacal lane. 7
It all looks beautifully obvious – in the rear mirror. But there are situations where it needs great imaginative power, combined with disrespect for the traditional currents of thought, to discover the obvious. The scant information we have about the personality of Herakleides shows that he had both: originality, and contempt for academic tradition. He was nicknamed by his acquaintances the paradoxolog – a maker of paradoxes; Cicero relates that he was fond of telling "puerile fables" and "marvellous stories"; and Proclus tells us that he had the audacity to contradict Plato, who taught the immobility of the earth. 8
The idea that the two lower planets – and only these two – were satellites of the sun, while the sun itself and the remaining planets still revolved round the earth, became later known by the misnomer "Egyptian System" and gained great popularity ( Fig. B, p. 46). It was evidently a half-way house between the geocentric (earth-centred) and heliocentric (sun-centred) conceptions of the universe. We do not know whether Herakleides stopped there, or whether he took the further step of letting the three outer planets also go around the sun, and the sun, with all his five satellites, go round the earth ( Fig. C, p. 46). It would have been a logical step, and some modern scholars believe that Herakleides did reach this three-quarter-way house 9. Some even believe that he also took the ultimate step of making all the planets, including the earth, revolve around the sun.
But whether he went the whole way to the modern conception of the solar system or not, is merely a matter of historic curiosity, for his successor, Aristarchus, certainly did.
3. The Greek Copernicus
Aristarchus, last of the line of the Pythagorean astronomers, came, like the Master, from Samos; and he is supposed to have been born, symbolically, in the same year, 310 B.C., in which Herakleides died. * Only one short treatise of his survives: On the Sizes and Distances of the Sun and Moon. It shows that he had the basic gifts required of a modern scientist: originality of thought and meticulousness in observation. The elegant method he designed for calculating the distance of the sun was followed by astronomers throughout the Middle Ages; if his actual figures were wrong, it was due to the fact that he was born two thousand years before the telescope. But though an equal distance separated him from the invention of the pendulum clock, he improved the estimates of the length of the solar year by adding 1/1623 to the previous estimate of 365 1/4 days.
____________________
*
These dates are rather conjectural. But astronomers have a knack for timing their life-orbits: Galileo died in the year Newton was born; and Newton was born exactly a hundred years after Copernicus died.
The treatise in which Aristarchus proclaimed that the sun, not the earth, was the centre of our world around which all planets revolve – this crowning achievement of Pythagorean cosmology, which Copernicus was to rediscover seventeen centuries later – is lost. But fortunately, we have the testimony of no smaller authorities than Archimedes and Plutarch, among others; and the fact that Aristarchus taught the heliocentric system is unanimously accepted by the ancient sources and modern scholars.
Archimedes, the greatest mathematician, physicist and inventor of antiquity, was a younger contemporary of Aristarchus. One of his most curious works is a little treatise called The Sand Reckoner, dedicated to King Gelon of Syracuse. It contains the crucial phrase: "For he ( Aristarchus of Samos) supposed that the fixed stars and the sun are immovable, but that the earth is carried round the sun in a circle..." 10
Plutarch's reference to Aristarchus is equally important. In his treatise On the Face in the Moon Disc, one of the characters refers to Aristarchus of Samos who thought "that the heaven is at rest, but that the earth revolves in an oblique orbit, while it also rotates about its own axis." 11
Thus Aristarchus of Samos had carried the development which started with Pythagoras and was continued by Philolaus and Herakleides, to its logical conclusion: the sun-centred universe. But here the development comes to an abrupt end. Aristarchus had no disciples and found no followers. 12 For nearly two millennia the heliocentric system was forgotten – or, shall one say, repressed from consciousness? – until an obscure Canon in Varmia, a remote outpost in Christendom, picked up the thread where the Samian had left off.
This paradox would be easier to understand if Aristarchus had been a crank, or a dilettante whose ideas were not taken seriously. But his treatise On the Sizes and Distances of the Sun and Moon became a classic of antiquity, and shows him as one of the foremost astronomers of his time; his fame was so great that nearly three centuries later Vitruvius, the Roman architect, starts his list of universal geniuses of the past with: "Men of this type are rare, men such as were in times past Aristarchus of Samos..." 13
In spite of all this, his correct hypothesis was rejected in favour of a monstrous system of astronomy, which strikes us today as an affront to human intelligence, and which reigned supreme for fifteen hundred years. The reasons for this benightedness will emerge only gradually, for we are faced here with one of the most astonishing examples of the devious, nay crooked ways of the "Progress of Science" – which is one of the main topics of this book.
IV THE FAILURE OF NERVE
1. Plato and Aristotle
BY the end of the third century B.C., the heroic period of Greek science was over. From Plato and Aristotle onward, natural science begins to fall into disrepute and decay
, and the achievements of the Greeks are only rediscovered a millennium and a half later. The Promethean venture which had started around 600 B.C., had within three centuries spent its elan; it was followed by a period of hibernation, which lasted five times as long.
From Aristarchus there is, logically, only one step to Copernicus; from Hippocrates, only a step to Paracelsus; from Archimedes, only a step to Galileo. And yet the continuity was broken for a time-span nearly as long as that from the beginning of the Christian era to our day. Looking back at the road along which human science travelled, one has the image of a destroyed bridge with rafters jutting out from both sides; and in between, nothing.
We know how this happened; if we knew exactly why it happened, we would probably have the remedy to the ills of our own time. For the breakdown of civilization during the Dark Ages is in some respects the reverse of the breakdown that started, though less dramatically, in the Age of Enlightenment. The former can be broadly described as a withdrawal from the material world, contempt for knowledge, science and technology; rejec- tion of the body and its pleasures in favour of the life of the spirit. It reads like a mirror-writing to the tenets of the age of scientific materialism which begins with Galileo and ends with the totalitarian state and the hydrogen bomb. They have only one factor in common: the divorce of reason from belief.
On the watershed that separates the heroic age of science from the age of its decline, stand the twin peaks, Plato and Aristotle. Two quotations may illustrate the contrast in philosophical climate on the two sides of the watershed. The first is a passage from a writer belonging to the Hippocratic school, and dates presumably from the fourth century B.C."It seems to me," he says, dealing with that mysterious affliction, epilepsy, "that the disease is no more 'divine' than any other. It has a natural cause, just as other diseases have. Men think it divine merely because they do not understand it. But if they called everything divine which they do not understand, why, there would be no end of divine things!" 1 The second quotation is from Plato's Republic and sums up his attitude to astronomy. The stars, he explains, however beautiful, are merely part of the visible world which is but a dim and distorted shadow or copy of the real world of ideas; the endeavour to determine exactly the motions of these imperfect bodies is therefore absurd. Instead: "let us concentrate on (abstract) problems, said I, in astronomy as in geometry, and dismiss the heavenly bodies, if we intend truly to apprehend astronomy." 2
Plato is equally hostile to the Pythagoreans' first and favourite branch of science. "The teachers of harmony," he lets Socrates complain, "compare the sounds and consonances which are heard only, and their labour, like that of the astronomers, is vain.' 3
None of this was probably meant to be taken quite literally, but it was – by that extremist school of Neoplatonism which dominated Western philosophy for several centuries, and stifled all progress in science – until, in fact, Aristotle was rediscovered and interest in nature revived. I have called them twin peaks separating two epochs of thought; but insofar as their influence on the future is concerned, Plato and Aristotle should rather be called twin-stars with a single centre of gravity, which circle round each other and alternate in casting their light on the generations that succeeded them. Until the end of the twelfth century, as we shall see, Plato reigned supreme; then Aristotle was resurrected and remained for two hundred years the philosopher, as he was commonly called; then Plato made a come-back, in an entirely different guise. Professor Whitehead's famous remark: "the safest general characterization of the European philosophical tradition is that it consists in a series of footnotes to Plato" could be amended by: "Science, up to the Renaissance, consisted in a series of footnotes to Aristotle."
The secret of their extraordinary influence, intermittently stimulating and choking European thought, during such a near-astronomical period, has been the subject of passionate and neverending controversy. It is, of course, not due to any single reason, but to the confluence of a multitude of causes at a particularly critical point of history. To mention only a few, starting with the most obvious: they are the first philosophers of antiquity whose writings survived not in odd fragments, in second- or third-hand quotations, but in massive bulk ( Plato's authenticated dialogues alone make a volume of the length of the Bible), embracing all domains of knowledge and the essence of the teachings of those who came before them; as if after an atomic war, among the torn and charred fragments, a complete Encyclopaedia Britannica had been preserved. Apart from bringing together all the relevant items of available knowledge in an individual synthesis, they were of course, in their own right, original thinkers of great creative power in such varied fields as metaphysics, biology, logics, epistemology and physics. They both founded "schools" of a new kind: the first Academy and the first Lyceum, which survived for centuries as organized institutions, and transformed the founders' once fluid ideas into rigid ideologies, Aristotle's hypotheses into dogmas, Plato's visions into theology. Then again, they were truly twin-stars, born to complement each other; Plato the mystic, Aristotle the logician; Plato the belittler of natural science, Aristotle the observer of dolphins and whales; Plato, the spinner of allegorical yarns, Aristotle the dialectician and casuist; Plato, vague and ambiguous, Aristotle precise and pedantic. Lastly – for this catalogue could be continued forever – they evolved systems of philosophy which, though different and even opposed in detail, taken jointly seemed to provide a complete answer to the predicament of their time.
The predicament was the political, economic and moral bankruptcy of classical Greece prior to the Macedonian conquest. A century of constant war and civil strife had bled the country of men and money; venality and corruption were poisoning public life; hordes of political exiles, reduced to the existence of homeless adventurers, were roaming the countryside; legalized abortion and infanticide were further thinning out the rank of citizens. The history of the fourth century, wrote a modern authority, "is in some of its aspects that of the greatest failure in history... Plato and Aristotle ... each in his different way tries (by suggesting forms of constitution other than those under which the race had fallen into political decadence) to rescue that Greek world which was so much to him, from the political and social disaster to which it is rushing. But the Greek world was past saving." 4
The political reforms suggested by them concern us only insofar as they indicate the unconscious bias which permeates their cosmology; but in this context, they are relevant. Plato's Utopia is more terrifying than Orwell's 1984 because Plato desires to happen what Orwell fears might happen. "That Plato's Republic should have been admired, on its political side, by decent people, is perhaps the most astonishing example of literary snobbery in all history," remarked Bertrand Russell. 5 In Plato's Republic, the aristocracy rules by means of the "noble lie", that is, by pretending that God has created three kinds of men, made respectively of gold: the rulers, silver: the soldiers, and base metals: the common man. Another pious lie will help to improve the race: when marriage is abolished, people will be made to draw mating-lots, but the lots will be secretly manipulated by the rulers according to the principles of eugenics. There will be rigid censorship; no young person must be allowed to read Homer because he spreads disrespect of the gods, unseemly merriment, and the fear of death, thus discouraging people from dying in battle.
Aristotle's politics move along less extreme, but essentially similar lines. He criticizes some of Plato's most provocative formulations, but not only does he regard slavery as the natural basis of the social order – "the slave is totally devoid of any faculty of reasoning" 6 ; he also deplores the existence of a "middle" class of free artisans and professional men, because their superficial resemblance to the rulers brings discredit on the latter. Accordingly, all professionals are to be deprived of the rights of citizenship in the Model State. It is important to understand the source of this contempt of Aristotle for artisans, craftsmen architects, engineers and the like – by contrast, say, to the high esteem in which an Eupalinos, th
e tunnel-builder, had been held in Samos. The point is that Aristotle believed them no longer to be necessary, because applied science and technology had already completed their task. Nothing further need, or could, be invented to make life more comfortable and enjoyable, because "nearly all requisites of comfort and social refinement have been secured" and "everything of these kinds has already been provided." 7 Pure science and philosophy "which deal neither with the necessities nor with the enjoyment of life" only arose, in Aristotle's view, after the practical sciences had done all that they can ever do, and material progress had come to a halt.
Even these cursory remarks may indicate the general mood underlying these philosophies: the 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. "Change" for Plato is virtually synonymous with degeneration; his history of creation is a story of the successive emergence of ever lower and less worthy forms of life – from God who is pure self-contained Goodness, to the World of Reality which consists only of perfect Forms or Ideas, to the World of Appearances, which is a shadow and copy of the former; and so down to man: "Those of the men first created who led a life of cowardice and injustice were suitably reborn as women in the second generation, and this is why it was at this particular juncture that the gods contrived the lust for copulation." After the women we come to the animals: "Beasts who go on all fours came from men who were wholly unconversant with philosophy and had never gazed on the heavens." 8 It is a tale of the Fall in permanence: a theory of descent and devolution – as opposed to evolution by ascent.