The Sleepwalkers by Arthur Koestler

[Boojatta]

The historical importance of the idea that disinterested science leads to the purification of the soul and its ultimate liberation, can hardly be exaggerated. The Egyptians embalmed their corpses so that the soul might return to them and need not be reincarnated again; the Buddhists practiced non-attachment to escape the wheel; both attitudes were negative and socially sterile. The Pythagorean concept of harnessing science to the contemplation of the eternal entered, via Plato and Aristotle, into the spirit of Christianity and became a decisive favor in the making of the Western world.
(from page 37)

(...)

There is something profoundly distasteful about Ptolemy’s universe; it is the work of a pedant with much patience and little originality, doggedly piling ‘orb in orb’. All the basic ideas of the epicyclic universe, and the geometrical tools for it, had been perfected by his predecessor, Hipparchus; but Hipparchus had only applied them to the construction of orbits for the sun and moon. Ptolemy completed the unfinished job, without contributing any idea of great theoretical value.

Hipparchus flourished about 125 BC, more than a century after Aristarchus; and Ptolemy flourished around AD 150, nearly three centuries after Hipparchus. In this span of time, nearly equal to the duration of the Heroic Age, practically no progress was made (...) Ptolemy was the last great astronomer of the Alexandrian School. (...) But nothing else turned up to replace it for nearly a millennium and a half. Ptolemy’s Almagest remained the Bible of astronomy until the beginning of the seventeenth century.

To get this extraordinary phenomenon into a proper perspective, one must not only be on guard against the wisdom of hindsight, but also against the opposite attitude, that kind of benevolent condescension which regards the past follies of Science as the unavoidable consequences of ignorance or superstition: our forebears just did not know better’. The point I shall try to make is that they did know better and that to explain the extraordinary cul de sac into which cosmology had maneuvered itself, we must look for more specific causes.

In the first place, the Alexandrian astronomers can hardly be accused of ignorance. They had more precise instruments for observing the stars than Copernicus had. Copernicus himself, as we shall see, hardly bothered with star-gazing; he relied on the observations of Hipparchus and Ptolemy. He knew no more about the actual motions in the sky than they did. (...)
(from pages 72 and 73)

(...)

Their main concern (they being the post-Aristotelian astronomers of ancient Greece) was ‘to save the appearances’. The original meaning of this ominous 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 mean 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, i.e. whether it was physically possible or not. Astronomy, after Aristotle, becomes an abstract sky-geometry, divorced from physical reality. Its principal task is to explain away the scandal of non-circular motions in the sky. It serves a practical purpose as a method for computing tables of the motions of the sun, moon, and planets; but as to the real nature of the universe, it has nothing to say.
(from page 77)

(...)

It looks as if the wheel had come full circle, back to the early Babylonians. They too had been highly competent observers and calendar-makers, who combined their exact science with a mythological dream-world. In the universe of Ptolemy, inter-locking canals of perfect circles have replaced the heavenly waterways, along which the star-gods sail their barges on their precisely charted journeys. The Platonic mythology of the sky was more abstract and less colorful, but as irrational and dream-born as the older one.

The three fundamental conceits of this new mythology were: the dualism of the celestial and sub-lunary worlds; the immobility of the earth in the centre; and the circularity of all heavenly motion.
(from page 79)


(...)

The medieval universe, as a modern scholar remarked, is thus not really geocentric, but ‘diabolocentric’. Its centre, once the Hearth of Zeus, is now occupied by Hell.
(from page 99)
(...)

The extraordinary power of this medieval vision of the universe is illustrated by the fact that it had the same, undiminished hold on the imagination of the Elizabethan poets at the turn of the sixteenth century as it had on Dante’s at the turn of the thirteenth; and it still echoed, in a famous passage by Pope, in the eighteenth.
(from page 100)

[bemildred]

1. Koestler has always been one of my favorites.

I may have to get a copy of this one. Allow me to recommend "Act of Creation" and "Ghost in the Machine" in return, if you have not run across them yet.

With regard to his thesis, I can't say much without reading it. However it is true that one can do perfectly good approximations of celestial motions using epicycles, the virtue of Newton is that his mathematics is simpler and it provides a better explanation for what happens, it doesn't beg the question of what reality "really is" quite as much. So, it is Occam's Rule that tells us Newton is better, and the relative ease of computation with the calculus.

The inefficacy of faith and obedience to authority as methods of discovery doesn't really need much discussion.

[Boojatta]

3. "The inefficacy of faith and obedience to authority ...

... as methods of discovery doesn't really need much discussion."

If an authority doesn't demand the use of some particular methods for creating new systems of ideas, but simply demands that some particular fixed system of ideas be accepted, then of course the authority doesn't support the creation of alternatives to that particular, fixed system of ideas. That seems to be self-evident and not something that requires historical evidence.

More excerpts:

(...) no branch of Science, ancient or modern, can boast freedom from metaphysical bias of one kind or another. The progress of Science is generally regarded as a kind of clean, rational advance along a straight ascending line; in fact it has followed a zigzag 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 (...) of a sleepwalker's performance (...)

from page 11 (in the Preface)

The Book of the Revolutions of the Heavenly Spheres was and is an all-time worst seller.

Its first edition, Nuremberg 1543, numbered a thousand copies, which were never sold out. It had altogether four reprints in four hundred years: Basle 1566, Amsterdam 1617, Warsaw 1854, and Torun 1873.

It is a remarkably negative record, and quite unique among books which made history. To appreciate its significance, it must be compared with the circulation of other contemporary works on astronomy. (...)

It is amusing to note that even the most conscientious modern scholars, when writing about Copernicus, unwittingly betray that they have not read him. The give-away is the number of epicycles in the Copernican system. At the end of his Commentariolus, Copernicus had announced (see p. 149 f.): 'altogether, therefore, thirty-four circles suffice to explain the entire structure of the universe and the entire ballet of the planets.' But the Commentariolus had merely been an optimistic preliminary announcement; when Copernicus got down to detail in the Revolutions, he was forced to add more and more wheels to his machinery, and the number grew to nearly fifty. (...)

Moreover, Copernicus had exaggerated the number of epicycles in the Ptolemaic system. Brought up to date by Peurbach in the fifteenth century, the number of circles required in the Ptolemaic system was not eighty, as Copernicus said, but forty.

In other words, contrary to popular, and even academic belief, Copernicus did not reduce the number of circles, but increased them (from forty to forty-eight). How could this mistaken idea survive for so long, and be repeated by so many eminent authorities? The answer is that very few people, even among professional historians of science, have read Copernicus' book, because the Copernican system (as opposed to the heliocentric idea) is hardly worth bothering about. Not even Galileo seems to have read it, as we shall see.

from pages 194-195

He (Copernicus) took back with him one idea only which the Pythagorean revival had brought into fashion: the motion of the earth; and he spent the rest of his life trying to fit it into a medieval framework, based on Aristotelian physics and Ptolemaic wheels. (...)

Copernicus was the last of the Aristotelians among the great men of science. In their attitude to nature, men life Roger Bacon, Nicolas of Cusa, William of Ockham, and Jean Buridan, who predated him by a century or two, were 'moderns' compared to Copernicus (...)

(...) at Merton College and at the Sorbonne, a century and a half before him, a succession of men of lesser fame than Copernicus had shaken off the authority of Aristotelian physics to which he remained a life-long slave.

(...)

His absolute reliance not only on the physical dogmata, but on the astronomic observations of the ancients was the main reason for the errors and absurdities of the Copernican system. When the Nuremberg mathematician Johannes Werner published a treatise On the Motion of the Eighth Sphere, in which he permitted himself to question the reliability of certain observations of Ptolemy and Timocharis, Copernicus attacked him with venom: (...)

from pages 202 and 203

The Lutherans, not the Catholics, had been the first to attack the Copernican system -- which prevented neither Rheticus nor Kepler from defending it in public. The Catholics, on the other hand, were uncommitted. In Copernicus' own day, they were favourably inclined towards him -- it will be remembered how Cardinal Schoenberg and Bishop Giese had urged him to publish his book. Twenty years after its publication, the Council of Trent re-defined Church doctrine and policy in all its aspects, but it had nothing to say against the heliocentric system of the universe. Galileo himself, as we shall see, enjoyed the active support of a galaxy of Cardinals, including the future Urban VIII, and of the leading astronomers among the Jesuits. Up to the fateful year 1616, discussion of the Copernican system was not only permitted, but encouraged by them -- under the one proviso, that it should be confined to the language of science, and should not impinge on the theological matters. (...)

Thus legend and hindsight combined to distort the picture, and gave rise to the erroneous belief that to defend the Copernican system as a working hypothesis entailed the risk of ecclesiastical disfavour or persecution. During the first fifty years of Galileo's lifetime, no such risk existed and the thought did not even occur to Galileo. What he feared is clearly stated in his letter: to share the fate of Copernicus, to be mocked and derided: ridendus et explodendum -- 'laughted at and hissed off the stage' are his exact words. Like Copernicus, he was afraid of the ridicule both of the unlearned and learned asses, but particularly of the latter: his fellow professors at Pisa and Padua, the stuffed shirts of the peripatetic school, who still considered Aristotle and Ptolemy as absolute authority. And this fear, as will be seen, was fully justified.

from pages 362 and 363

[sarge43]

2. That book should be read by anyone interested in the history of

science. Truly seminal.

Another quote: Alphonso X of Castile, called the Wise, who was a pious man and a great patron of astronomy, put the matter more succinctly. When he was initiated into the Ptolemaic system, he sighed: "If the Lord Almighty had consulted me before embarking upon the Creation, I should have recommended something simpler."