The Sleepwalkers

  As so often with Plato, it is impossible to say whether all this is to be taken literally, or allegorically, or as an esoteric leg-pull. But there can be no doubt concerning the basic trend of the whole system.

  We shall have to hark back time and again to Plato, to pick up the scent of some particular later development. For the time being, let us retain this essential clue to Plato's cosmology: his fear of change, his contempt and loathing for the concepts of evolution and mutability. It will reverberate all through the Middle Ages, together with its concomitant yearning for a world of eternal, changeless perfection:

  Then agin I think on that which Nature said

  Of that same time when no more change shall be,

  But steadfast rest of all things, firmly stay'd

  Upon the pillars of eternity,

  That is contrary to mutability. 9

  This "mutation phobia" seems to be mainly responsible for the repellent aspects of Platonism. The Pythagorean synthesis of religion and science, of the mystical and empirical approach is now in shambles. The mysticism of the Pythagoreans is carried to sterile extremes, while empirical science is ridiculed and discouraged. Physics is separated from mathematics and made into a department of theology. The Pythagorean Brotherhood is transformed into the Guides of a totalitarian Utopia; the transmigration of souls on their way to God is debased by old-wife's tales, or edifying lies, about cowards being punished by feminine reincarnations; orphic asceticism curdles into hatred of the body and contempt for the senses. True knowledge cannot be obtained by the study of nature; for "if we would have true knowledge of anything, we must be quit of the body... While in company with the body, the soul cannot have true knowledge." 10

  All this is not an expression of humility – neither of the humility of the mystic seeker for God, nor the humility of reason acknowledging its limits; it is the half-frightened, half-arrogant philosophy of the genius of a doomed aristocracy and a bankrupt civilization. When reality becomes unbearable, the mind must withdraw from it and create a world of artificial perfection. Plato's world of pure Ideas and Forms, which alone is to be considered as real, whereas the world of nature which we perceive is merely its cheap Woolworth copy, is a flight into delusion. The intuitive truth expressed in the allegory of the Cave is here carried to absurdity by over-concretization – as if the author of the line "this world is a vale of tears" were to proceed with a factual survey of the distribution of tear-drops in the vale.

  Once again one must remember, that in the surrealistic cosmogony of the Timaeus it is impossible to draw the line between philosophy and poetry, metaphorical and factual statement; and that long passages in the Parmenides virtually destroy the doctrine that the world is a copy of models in heaven. But if some of my previous paragraphs sound like a harsh and one-sided view of what Plato meant, this is essentially what he came to mean to a long row of future generations – the one-sided shadow that he threw. We shall also see that the second Platonic revival, in the fifteenth century, highlighted a quite different side of Plato, and threw his shadow into the opposite direction. But that turn is still a long way ahead.

  2. Rise of the Circular Dogma

  I must now turn to Plato's contribution to astronomy – which insofar as concrete advances are concerned, is nil; for he understood little of astronomy, and was evidently bored by it. The few passages where he feels moved to broach the subject are so muddled, ambiguous or self-contradictory, that all scholarly efforts have failed to explain their meaning. 11

  However, by a process of metaphysical and a priori reasoning, Plato came to certain general conclusions regarding the shape and motions of the universe. These conclusions, of paramount importance for everything which follows, were that the shape of the world must be a perfect sphere, and that all motion must be in perfect circles at uniform speed.

  "And he gave the universe the figure which is proper and natural... Wherefore he turned it, as in a lathe, round and spherical, with its extremities equidistant in all directions from the centre, the figure of all figures most perfect and most like to itself, for he deemed the like more beautiful than the unlike. To the whole he gave, on the outside round about, a surface perfectly finished and smooth, for many reasons. It had no need of eyes, for nothing visible was left outside it; nor of hearing, for there was nothing audible outside it; and there was no breath outside it requiring to be inhaled... He allotted to it the motion which was proper to its bodily form, that motion of the seven motions which is most bound up with understanding and intelligence. Wherefore, turning it round in one and the same place upon itself, he made it move with circular rotation; all the other six motions [i.e., straight motion up and down, forward and back, right and left] he took away from it and made it exempt from their wanderings. And since for this revolution it had no need of feet, he created it without legs and without feet... Smooth and even and everywhere equidistant from the centre, a body whole and perfect, made up of perfect bodies..." 12

  Accordingly, the task of the mathematicians was now to design a system which would reduce the apparent irregularities in the motions of the planets to regular motions in perfectly regular circles. This task kept them busy for the next two thousand years. With his poetic and innocent demand, Plato laid a curse on astronomy, whose effects were to last till the beginning of the seventeenth century, when Kepler proved that planets move in oval, and not circular orbits. There is perhaps no other example in the history of thought of such dogged, obsessional persistence in error, as the circular fallacy which bedevilled astronomy for two millennia.

  But here again, Plato had merely thrown out, in semi-allegorical language, a suggestion which was quite in keeping with the Pythagorean tradition; it was Aristotle who promoted the idea of circular motion to a dogma of astronomy.

  3. The Fear of Change

  In Plato's world the boundaries between the metaphorical and the factual are fluid; all such ambiguity disappears as Aristotle takes over. With pedantic thoroughness the vision is dissected, its poetic tissue is preserved in vitro, its volatile spirit condensed and frozen. The result is the Aristotelian model of the universe.

  The Ionians had prised the world-oyster open, the Pythagoreans had set the earth-ball adrift in it, the Atomists dissolved its boundaries in the infinite. Aristotle closed the lid again with a bang, shoved the earth back into the world's centre, and deprived it of motion.

  I shall describe the model first in its broad outline, and fill in the details later.

  The immobile earth is surrounded, as in the earlier cosmologies, by nine concentric, transparent spheres, enclosing each other like the skins of an onion (see Fig. A, p. 46). The innermost skin is the sphere of the moon; the two outermost are the sphere of the fixed stars, and beyond that, the sphere of the Prime Mover, who keeps the whole machinery turning: God.

  The God of Aristotle no longer rules the world from the inside, but from the outside. It is the end of the Pythagorean central fire, the hearth of Zeus, as a divine source of cosmic energy; the end of Plato's mystic conception of the anima mundi, of the world as a living animal possessed with a divine soul. Aristotle's God, the Unmoved Mover, who spins the world round from outside it, is the God of abstract theology. Goethe's "Was wär' ein Gott der nur von aussen stiesse" – seems to be aimed directly at him. The removal of God's home from the centre to the periphery automatically transformed the central region, occupied by earth and moon, into that farthest away from Him: the humblest and lowliest of the whole universe. The space enclosed by the sphere of the moon and containing the earth – the "sub-lunary region" – is now considered definitely inferior. To this region, and to this region alone, are the horrors of Change, of mutability confined. Beyond the sphere of the moon, the heavens are eternal and unalterable.

  This splitting-up of the universe into two regions, the one lowly, the other exalted, the one subject to change, the other not, was to become another basic doctrine of mediaeval philosophy and cosmology. It brought a serene, cosmic reassurance to a frig
htened world by asserting its essential stability and permanence, but without going so far as to pretend that all change was mere illusion, without denying the reality of growth and decline, generation and destruction. It was not a reconciliation of the temporal and the eternal, merely a confrontation of the two; but to be able to take in both in one glance, as it were, was something of a comfort.

  The division was made intellectually more satisfactory and easier to grasp, by assigning to the two parts of the universe different raw materials and different motions. In the sub-lunary region, all matter consisted of various combinations of the four elements, earth, water, air and fire, which themselves were combinations of two pairs of opposites, hot and cold, dry and wet. The nature of these elements requires that they move in straight lines: earth downward, fire upward, air and water horizontally. The atmosphere fills the whole sub-lunary sphere, though its upper reaches consist not of proper air, but of a substance which, if set in motion, will burn and produce comets and meteors. The four elements are constantly being transformed one into the other, and therein lies the essence of all change.

  But we go beyond the moon's sphere, nothing changes, and none of the four terrestrial elements is present. The heavenly bodies consist of a different, pure and immutable "fifth element", which becomes the purer the farther away from the earth. The natural motion of the fifth element, as opposed to the four earthly elements, is circular, because the sphere is the only perfect form, and circular motion is the only perfect motion. Circular motion has no beginning and no end; it returns into itself and goes on forever: it is motion without change.

  The system had yet another advantage. It was a compromise between two opposite trends in philosophy. On the one side there was the "materialistic" trend, which had started with the Ionians, and was continued by men like Anaxagoras, who believed that homo sapiens owed his superiority to the dexterity of his hand; by Heraklitus, who regarded the universe as a product of dynamic forces in eternal flux; and culminated in Leucippus and Democritus, the first atomists. The opposite tendency, which originated with the Eleatics, found its extreme expression in Parmenides, who taught that all apparent change, evolution and decline, were illusions of the senses, because whatever exists cannot arise from anything that does not, or is different from it; and that the Reality behind the illusion is indivisible, unchangeable, and in a state of static perfection. Thus, for Heraklitus Reality is a continuous process of Change and Becoming, a world of dynamic stresses, of creative tensions between opposites; whereas for Parmenides Reality is a solid, uncreated, eternal, motionless, changeless, uniform sphere. 13

  The preceding paragraph is, of course, a woeful oversimplification of developments in one of the liveliest periods of philosophic debate; but my purpose is merely to show how neatly the Aristotelian model of the universe solved the basic dilemma by handing over the sub-lunary region to the Materialists, and letting it be governed by Heraklitus' motto "all is change"; whereas the rest of the universe, eternal and immutable, stood in the sign of the Parmenidian "nothing ever changes".

  Once again, it was not a reconciliation, merely a juxtaposition, of two world-views, or "world-feelings", both of which have a profound appeal to the minds of men. This appeal was increased in power when, at a later stage, mere juxtaposition yielded to gradation between the opposites; when the original Aristotelian two-storey universe – all basement and loft – was superseded by an elaborately graded, multi-storeyed structure; a cosmic hierarchy where every object and creature had its exact "place" assigned to it, because its position in the many-layered space between lowly earth and high heaven defined its rank on the Scale of Values, in the Chain of Being. We shall see that this .concept of a closed-in cosmos graded like the Civil Service (except that there was no advancement, only demotion) survived for nearly a millennium and a half. It was really a Mandarin Universe. During these long centuries, European thought had more in common with Chinese or Indian philosophy than with its own past and future.

  However, even if European philosophy were only a series of footnotes to Plato, and even though Aristotle had a millennial stranglehold on physics and astronomy, their influence, when all is said, depended not so much on the originality of their teaching, as on a process of natural selection in the evolution of ideas. Out of a number of ideological mutations, a given society will select that philosophy which it unconsciously feels to be best suited for its need. Each time, in subsequent centuries, when the cultural climate changed in Europe, the twin stars also changed their aspect and colour: Augustine and Aquinas, Erasmus and Kepler, Descartes and Newton each read a different message in them. Not only did the ambiguities and contradictions in Plato, the dialectical twists in Aristotle, admit a wide range of interpretations and shifts of emphasis; but, by taking the two jointly or in alternation, by combining selected facets of each, the total effect could virtually be reversed; we shall see that the "New Platonism" of the sixteenth century was in most respects the opposite of the Neoplatonism of the early Middle Ages.

  In this context I must briefly return to Plato's loathing for change – for "generation and decay" – which made the sublunary sphere such a disreputable slum-district of the universe.

  Aristotle himself did not share this loathing. As a keen biologist, he regarded all change, all movement in nature as purposeful and goal-directed – even the motions of inanimate bodies: a stone will fall to the earth, as a horse will canter to its stable, because that is its "natural place" in the universal hierarchy. We shall have occasion, later on, to marvel at the disastrous effects of this Aristotelian brainwave on the course of European science; at the moment, I merely wish to point out that Aristotle's attitude to Change, though he rejects evolution and progress, is not quite as defeatist as Plato's. 14 Yet Neoplatonism, in its dominant trend, ignores Aristotle's dissent on this essential point, and manages to make the worst of both worlds. It adopts the Aristotelian scheme of the universe, but makes the sub-lunary sphere a Platonic vale of shadows; it follows the Platonic doctrine of the natural world as a dim copy of ideal Forms – which Aristotle rejected – yet follows Aristotle in placing the Prime Mover outside the confines of the world. It follows both in their anxious effort to build a walled-in universe, protected against the Barbarian incursions of Change; a nest of spheres-within-spheres, eternally revolving in themselves, yet remaining in the same place; thus hiding its one shameful secret, that centre of infection, safely isolated in the sub-lunary quarantine.

  In the immortal parable of the Cave, where men stand in their chains backs to the light, perceiving only the play of shadows on the wall, unaware that these are but shadows, unaware of the luminous reality outside the Cave – in this allegory of the human condition, Plato hit an archetypal chord as pregnant with echoes as Pythagoras' Harmony of the Spheres. But when we think of Neoplatonism and Scholasticism as concrete philosophies and precepts of life, we may be tempted to reverse the game, and to paint a picture of the founders of the Academy and the Lyceum as two frightened men standing in the self-same Cave, facing the wall, chained to their places in a catastrophic age, turning their backs on the flame of Greece's heroic era, and throwing grotesque shadows which are to haunt mankind for a thousand years and more.

  V THE DIVORCE FROM REALITY

  1. Spheres Within Spheres (Eudoxus)

  IN a closed universe, where the fixed stars offered as yet no specific problems, the challenge to understanding came from the planets; the chief task of cosmology was to devise a system which explained how sun, moon and the remaining five planets moved.

  This task was further narrowed down when Plato's dictum that all heavenly bodies move in perfect circles, became the first Academic dogma in the first institution that bore that solemn name. The task of Academic astronomy was now to prove that the apparently irregular meanderings of the planets were the result of some combination of several simple, circular, uniform motions.

  The first serious attempt was made by Plato's pupil Eudoxus, and improved by the latter's pu
pil, Calippus. It is an ingenious attempt – Eudoxus was a brilliant mathematician, to whom most of Euclid's fifth book is due. In the earlier geocentric models of the universe, each planet, we remember, was attached to a transparent sphere of its own, and all spheres were turning round the earth. But, since this did not account for the irregularities of their motions, such as standing occasionally still and going backward for a while: their "stations" and "retrogressions", Eudoxus assigned to each planet not one, but several spheres. The planet was attached to a point on the equator of a sphere, which rotates round its axis, A. The two ends of this axis are let into the inner surface of a concentric larger sphere S 2, which rotates round a different axis, A 2 and carries A around with it. The axis of S 2 is attached to the next larger sphere S 3, which rotates again round a different axis A 3 : and so on. The planet will thus participate in all the independent rotations of the various spheres which form its "nest"; and by letting each sphere rotate at the appropriate tilt and speed, it was possible to reproduce roughly – though only very roughly – the actual motion of each planet. 1 The sun and moon needed a nest of three spheres each, the other planets four spheres each, which (with the modest single sphere assigned to the multitude of fixed stars) made altogether twenty-seven spheres. Calippus improved the system at the price of adding seven more spheres, making a total of thirty-four. It is at this point that Aristotle came in.