The Cosmological Ideas of the Greeks*

46 SCIENTIFIC AMERICAN SUPPLEMENT No. 2115 Ju�y 15,1916

Philosophy Which Aimed to Comprehend the World In a Natural Way

Hector MacPherson, M.A., F.R.A.S.

(I) THE SPECULATIVE PERIOD. beings is moist and that heat itself is generated from earth was considered to be flat, and the sun and moon were To THE ancient Greoks belongs the honor of separating, moisture, and persists in it (for that from which all supposed to be composed of similar matter-a consider for the first time, cosmology from t.heology. ,fust as the things spring is the first principle of them) and getting able advance in thonght. Anaxagoras also held the some genius of th� Hebrew people was religious, that of the this idea also from the faet that the germs of all beings are what absmd view that the 'Milk} Way represented the Hellenes was in the direction of philosophy and art. of a moist nature." Thales, at all events, has the dis shadow of the earth. And just as the Hebrews developed the religious view of tinction of being the first scientific philosopher. Empedocles-working from his idea of four primary the world, it fell to the Greeks to develop the philo Anaximander, the second philosopher of the Ionian elements, fire, air, water and earth, swayed to and fro sophic view. As ]Pythagoras was not only devoted to science cent to the Cimmerian land is F:rebus or the land of the nails to a solid vault. and philosophy; it was also a religious society :tnd a shades; in other pas�ages, however, Homer places Hades The Ionian school did not advance very far in the ex political organization. Hence it occupies a somewhat beneath the surface of the earth. planation of the world. At the other end of the Greek unique place in the history of Greek thought. Above the earth is the region of the ether; and still world, however, another school of thinkers-the Eleatics The underlying idea of Pythagoras was that the ex higher is the vault of the heaven. Beneath this vault -had arisen and they developed more advanced views. planation of everything is to 'be Rought in number. In the sun, moon and stars perform their motions, rising Xenophanes, the founder of the school, it is true, did the clear words of Dr. Dreyer, Pythagoras believed that out of Okeanos in the morn.ing and returning thither at not advance beyond the Ionion standpoint. The earth "number not merely represent.s the relations of the phe night. The Hesiodic conception is somewhat similar. he believed to be flat and "rooted in the infinite," while nomena to each ot·her but is. the substance of things, the Hesiod places Tartarus, "the depth," as far below the the sun, comets and stars were supposed to be fiery cause of every phenomenon of nature. Pythagoras and earth as the height of heaven is above. Thus, the whole clouds. The sun and stars were formed daily from fiery his followers were led to t.his assumption by perceiving universe is represented as a sphere. And this sphere is particles while the moon was a compressed cloud which how everything in nature is governed by numerical rela divided into two halves by the earth's surface. This shone by inherent light and was extinguished monthly. tions, how the celestial motions are performed with regu (Jonception is somewhat akin to that of the Hebrews, as Parmenides, the virtual founder of the Eleatic school, larity and how the harmony of musical Rounds depends brought out by Schiaparelli. In his "Theogony" Hesiod was a much more profound thinker. To him belongs the on regular intervals the numerical valuation .of which puts forth his cosmogonic views. How far this work is distinction of perceiving the spherical form of the earth they were the first to determine." Amid a great deal of the product of purely Hellenic thought is uneertain. a great advance in thought; he considered the entire uni fantastic speculation, Pythagoras seemA to have got hold Pfleiderer considers that the work "in many instances verse to consist of a number of concentric layers en of various aspects of truth. To him, the universe was a sphere; disarranged popular legends with foreign Asiatic specula circling the stationary earth. This is the first time, as and at its center was the earth, also of a spherical tion." Tn the beginning was Chaos, from which sprang Dr. Dyers observes, that we meet with the conception of figure. This view, held by Parmenides alone outside of the earth-goddess Gaia, the mother of all. Then follow concentric spheres. Parmenides also noticed that the the Pythagorean School, was now accepted by the dis Erebus and Aether, and these are followed by the pro moon appears "always gazing earnestly toward the rays ciples of the founder. duction of "Uranos, the god of the heaven, and from the of the sun" and he drew the correct deduction that it The Pythagoreans latterly advanced beyond their mas union of the god of heaven and Gaia, the goddess of shines by reflected light. He considered the sun and ter's cosmological standpoint. Philolaus taught that the earth. there springs the race of gods· and titans-personi moon to consist of materials detached from the "Milky apparent rotation of the starry sphere and the motion fications for the most part of natural forces. The only Way," and the stars to be nearer to the earth than the of the sun around the earth are caused by the movement important point about the theogony is the fact that the sun, an error similar to that of Anaximander. of the earth in twenty-four hours round the circumference 'earth sprang from Chaos. and from the union of Earth Curiously enough Heracleitus of Ephesus, who was a of a circle. This idea, incorrect though it was, marks a and Heaven the other personified natural forces were thinker at least. as profound as Parmenides, was much less real advance in scientific t;hought. Philolaus went a step further. produced. happy in his cosmological speculatlOns. Heracleitus found He considered that the earth could not be the What Hesiod actually meant by Chaos is uncertain. the explana.tion of the world in univsersal flux-"Be center of the universe, but that the earth and the other Plutarch believed it to be water; and in one or two (loming," ,"All things flow" ('It:CZvtlZ pet). Accordingly he celestial bodies moved round the "Central Fire" or the places, Homer speaks of Okeanos as the origin of every was led to consider fire to .be the "first principle" of the "Hearth of the universe." This body Philolaus and his thing. Here we have the connection of Greek and Baby world. There is, he taught, an unending circulation in followers held to be invisible from Greece and only to be seen in lonian mythology, as Dr. Dreyer notes, "the connecting nature "upward, downward, the way is one and the the regions beyond India. This doctrine called link between the primiti ve popular notions and the first "arne." Accordingly it was in keeping with the doc�rine forth the ridicule of Aristotle. "They forcibly make," attempt at philosophical enquiry." of fiux to revert to the idea of a flat earth. The sun he he said, "the phenomena fit their opinions and precon ceived notions This first attempt was due to Thales of Miletus, the believed to be formed of moist exhalations caught in a and attempt to construct the universe." first Greek philosopher. It is true that his idea of the hollow basin with its cavity facing the earth. The orb of In many ways the Pythagoreans deserved the ridicule constitution of the world was as primitive and, in the day was ignited every morning and extinguished every of the great philosopher. For instance, as ten was sup posed to be a perfect 'light of later knowledge, as absurd as those of Homer and night. On the whol;> Heracleitus' cosmological specula number, it was necessary to assume existence Hesiod. The earth, he believed, was a circular disk tions marked not an advance but a retrogression in the of ten celestial bodies. Only nine were known-the earth, floating like a piece of wood on the ocean; and in water thought. Indeed the marvelous intuition of Parmenides the sun, the moon, the five planets, and the Thales fomid the ultimate principles or substance of the seems to have been completely overlooked. Such illus sphere of the fixed stars. Therefore the Pytha goreans mag world. At first sight Thales may appear to have ad trious thinkers as Anaxagoras, Empedocles, Leucippus i ined the existence of another bOdy-the vanced but little beyond the standpoint of the poets; and Democritus erred fundamentally in regard to the "antichthon" or "counter-earth" perpetually invisible but there is one essential difference between his explana shape of the earth. from the inhabited side of our planet's surface. tion of the world and theirs. 'l'hales separated cosmo Anaxagoras believed that mind (vovs) had produced Yet with all their errors the Pythagorean School under Philolaus took logical from religious speculation. In his explanation of the world out of the original chao�-the most profound a remarkable step. They boldly declarei that the the universe there was no mythological element. No idea of the ultimate cause of the universe put forward chief place in the universe was not occupied by our d. gods or goddesses were invoked-as in the cosmology of before Plato and Aristotle. Mind formed the world by worl Hicetas of Syracuse seems to have gone still further and anticipated Hesiod and in the creation epic of the Babylonians. starting a rotatory movement, by which the present state partially the Copernican System. Cicero writi�g long Aristotle discussing Thales' belief in water. as the "first of things was produced. Matter was thus separated into afterward said that "Hicetas of Syra cuse, accordmg principle" s uggests that the Milesian philosopher got two halves, ether .and air. The air-cold, dark, and heavy to Theophrastus, believes that the heav -was ens, the sun, moon, the idea "because he saw that the nourishment of all agglomerated in the center, and from this was stars and all heavenly bodies, are standing still and that nothing * From Popu!at .4strunomy. produced water from whicrl again earth appeared. The in the universe is moving