I. Thales

Origin.

2. There can be no doubt that the founder of the Milesian school, and therefore the first of the cosmologists, was Thales;[[55]] but all we can really be said to know of him comes from Herodotos, and the romance of the Seven Wise Men was already in existence when he wrote. He tells us, in the first place, that Thales was of Phoenician descent, a statement which other writers explained by saying he belonged to the Thelidai, a noble house descended from Kadmos and Agenor.[[56]] This is clearly connected with the view of Herodotos that there were “Kadmeians” from Boiotia among the original Ionian colonists, and it is certain that there really were people called Kadmeians in several Ionic cities.[[57]] Whether they were of Semitic origin is, of course, another matter. Herodotos probably mentions the supposed descent of Thales simply because he was believed to have introduced certain improvements in navigation from Phoenicia.[[58]] At any rate, the name Examyes, which his father bore, lends no support to the view that he was a Semite. It is a Karian name, and the Karians had been almost completely assimilated by the Ionians. On the monuments, we find Greek and Karian names alternating in the same families, and there is therefore no reason to suppose that Thales was anything else than an ordinary Milesian citizen, though perhaps with Karian blood in his veins.[[59]]

The eclipse foretold by Thales.

3. By far the most remarkable statement that Herodotos makes about Thales is that he foretold the eclipse of the sun which put an end to the war between the Lydians and the Medes.[[60]] Now, we may be sure that he was quite ignorant of the true cause of eclipses. Anaximander and his successors certainly were so,[[61]] and it is incredible that the right explanation should once have been given and then forgotten so soon. Even supposing, however, Thales had known the cause of eclipses, no one can believe that such scraps of elementary geometry as he picked up in Egypt would enable him to calculate one from the elements of the moon’s path. Yet the evidence for the prediction is too strong to be rejected off-hand. The testimony of Herodotos to an event which must have happened about a hundred years before his own birth may, perhaps, be deemed insufficient; but that of Xenophanes is a very different matter, and it is this we have really to deal with.[[62]] According to Theophrastos, Xenophanes was a disciple of Anaximander, and he may quite well have seen and spoken with Thales. In any case, he must have known scores of people who were able to remember what happened, and he had no conceivable interest in misrepresenting it. The prediction of the eclipse is really better attested than any other fact about Thales whatsoever, and the evidence for it is about as strong as for anything that happened in the early part of the sixth century B.C.

Now it is quite possible to predict eclipses without knowing their true cause, and there is no doubt that the Babylonians actually did so. On the basis of their astronomical observations, they had made out a cycle of 223 lunar months, within which eclipses of the sun and moon recurred at equal intervals of time.[[63]] This, it is true, would not enable them to predict eclipses of the sun for a given spot on the earth’s surface; for these phenomena are not visible at all places where the sun is above the horizon at the time. We do not occupy a position at the centre of the earth, and what astronomers call the geocentric parallax has to be taken into account. It would only, therefore, be possible to tell by means of the cycle that an eclipse of the sun would be visible somewhere, and that it might be worth while to look out for it. Now, if we may judge from a report by a Chaldaean astronomer which has been preserved, this was just the position of the Babylonians. They watched for eclipses at the proper dates; and, if they did not occur, they announced the fact as a good omen.[[64]] To explain what we are told about Thales no more than this is required. He simply said there would be an eclipse; and, as good luck would have it, it was visible in Asia Minor, and on a striking occasion.

Date of Thales.

4. The prediction of the eclipse does not, then, throw much light upon the scientific attainments of Thales; but, if we can fix its date, it will give us a point from which to start in trying to determine the time at which he lived. Modern astronomers have calculated that there was an eclipse of the sun, probably visible in Asia Minor, on May 28 (O.S.), 585 B.C.,[[65]] while Pliny gives the date of the eclipse foretold by Thales as Ol. XLVIII. 4 (585/4 B.C.).[[66]] This, it is true, does not exactly tally; for May 585 belongs to the year 586/5 B.C. It is sufficiently near, however, to justify us in identifying the eclipse as that of Thales, and this is confirmed by Apollodoros, who fixed his floruit in the same year.[[67]] The further statement that, according to Demetrios Phalereus, Thales “received the name of wise” in the archonship of Damasias at Athens, agrees very well with this, and is doubtless based on the story of the Delphic tripod; for the archonship of Damasias is the era of the restoration of the Pythian Games.[[68]]

Thales in Egypt.

5. The introduction of Egyptian geometry into Hellas is universally ascribed to Thales, and it is extremely probable that he did visit Egypt; for he had a theory of the inundations of the Nile. In a well-known passage,[[69]] Herodotos gives three explanations of the fact that this alone of all rivers rises in summer and falls in winter; but, as his custom is in such cases, he does not name their authors. The first of them, however, that which attributes the floods to the Etesian winds, is ascribed to Thales in the Placita,[[70]] and also by many later writers. Now, those statements are derived from a treatise on the Rise of the Nile attributed to Aristotle and known to the Greek commentators, but now extant only in a Latin epitome of the thirteenth century.[[71]] In this work the first of the three theories mentioned by Herodotos is ascribed to Thales, the second to Euthymenes of Massalia, and the third to Anaxagoras. Where did Aristotle, or whoever wrote the book, get these names? We think naturally once more of Hekataios, whom Herodotos so often reproduces without mentioning his name; and this conjecture is much strengthened when we find that Hekataios actually mentioned Euthymenes.[[72]] We may conclude, then, that Thales really was in Egypt; and, perhaps, that Hekataios, in describing the Nile, took account, as was only natural, of his distinguished fellow-citizen’s views.

Thales and geometry.

6. As to the nature and extent of the mathematical knowledge brought back by Thales from Egypt, it seems desirable to point out that many writers have seriously misunderstood the character of the tradition.[[73]] In his commentary on the First Book of Euclid, Proclus enumerates, on the authority of Eudemos, certain propositions which he says were known to Thales.[[74]] One of the theorems with which he credits him is that two triangles are equal when they have one side and the two adjacent angles equal. This he must have known, said Eudemos, as otherwise he could not have measured the distances of ships at sea from a watch-tower in the way he was said to have done.[[75]] Here we see how all these statements arose. Certain remarkable feats in the way of measurement were traditionally ascribed to Thales, and it was assumed that he must have known all the propositions which these imply. But this is quite an illusory method of inference. Both the measurement of the distance of ships at sea, and that of the height of the pyramids, which is also ascribed to him,[[76]] are easy applications of what Aahmes calls the seqt. These rules of mensuration may well have been brought from Egypt by Thales, but we have no ground for supposing that he knew any more about their rationale than did the author of the Rhind papyrus. Perhaps, indeed, he gave them a wider application than the Egyptians had done. Still, mathematics, properly so called, did not come into existence till some time after Thales.

Thales as a politician.

7. Thales appears once more in the pages of Herodotos some time before the fall of the Lydian empire. He is said to have urged the Ionian Greeks to unite in a federal state with its capital at Teos.[[77]] We shall have occasion to notice more than once in the sequel that the early schools of philosophy were in the habit of trying to influence the course of political events; and there are many things, for instance the part played by Hekataios in the Ionian revolt, which point to the conclusion that the scientific men of Miletos took up a very decided position in the stirring times that followed the death of Thales. It is this political action which has gained the founder of the Milesian school his undisputed place among the Seven Wise Men; and it is owing mainly to his inclusion among those worthies that the numerous anecdotes which were told of him in later days attached themselves to his name.[[78]]

Uncertain character of the tradition.

8. If Thales ever wrote anything, it soon was lost, and the works which were written in his name did not, as a rule, deceive even the ancients.[[79]] Aristotle professes to know something about the views of Thales; but he does not pretend to know how they were arrived at, nor the arguments by which they were supported. He does, indeed, make certain suggestions, which are repeated by later writers as statements of fact; but he himself simply gives them for what they are worth.[[80]] There is another difficulty in connexion with the tradition. Many a precise-looking statement in the Placita has no other foundation than the habit of ascribing any doctrine which was, roughly speaking, characteristic of the whole Ionic “Succession” to “Thales and his followers,” and so producing the appearance of a definite statement about Thales. But, in spite of all this, we need not doubt that Aristotle was correctly informed with regard to the leading points. We have seen traces of reference to Thales in Hekataios, and nothing can be more likely than that later writers of the school should have quoted the views of its founder. We may venture, therefore, upon a conjectural restoration of his cosmology, in which we shall be guided by what we know for certain of the subsequent development of the Milesian school; for we should naturally expect to find its characteristic doctrines at least foreshadowed in the teaching of its earliest representative. But all this must be taken for just what it is worth; speaking strictly, we do not know anything about the teaching of Thales at all.

Conjectural account of the cosmology of Thales.

9. The statements of Aristotle may be reduced to three:

The first of these statements must be understood in the light of the second, which is expressed in Aristotelian terminology, but would undoubtedly mean that Thales had said water was the fundamental or primary thing, of which all other things were mere transient forms. It was, we shall see, just such a primary substance that the Milesian school as a whole was seeking, and it is unlikely that the earliest answer to the great question of the day should have been the comparatively subtle one given by Anaximander. We are, perhaps, justified in holding that the greatness of Thales consisted in this, that he was the first to ask, not what was the original thing, but what is the primary thing now; or, more simply still, “What is the world made of?” The answer he gave to this question was: Water.

Water.

10. Aristotle and Theophratos, followed by Simplicius and the doxographers, suggest several explanations of this answer. By Aristotle these explanations are given as conjectural; it is only later writers that repeat them as if they were quite certain.[[84]] The most probable view of them seems to be that Aristotle simply ascribed to Thales the arguments used at a later date by Hippon of Samos in support of a similar thesis.[[85]] This would account for their physiological character. The rise of scientific medicine had made biological arguments very popular in the fifth century; but, in the days of Thales, the prevailing interest was not physiological, but rather what we should call meteorological, and it is therefore from this point of view we must try to understand the theory.

Now it is not very hard to see how considerations of a meteorological kind may have led Thales to adopt the view he did. Of all the things we know, water seems to take the most various shapes. It is familiar to us in a solid, a liquid, and a vaporous form, and so Thales may well have thought that he saw the world-process from water and back to water again going on before his very eyes. The phenomenon of evaporation naturally suggests everywhere that the fire of the heavenly bodies is kept up by the moisture which they draw from the sea. Even at the present day, the country people speak of the appearance of sunbeams as “the sun drawing water.” Water comes down again in the rain; and lastly, so the early cosmologists thought, it turns to earth. This seems strange to us, but it may have seemed natural enough to men who were familiar with the river of Egypt which had formed the Delta, and with the torrents of Asia Minor, which bring down unusually large alluvial deposits. At the present day the Gulf of Latmos, on which Miletos used to stand, is completely filled up. Lastly, they thought, earth turns once more to water—an idea derived from the observation of dew, night-mists, and subterranean springs. For these last were not in early times supposed to have anything at all to do with the rain. The “waters under the earth” were regarded as an entirely independent source of moisture.[[86]]

Theology.

11. The third of the statements mentioned above is supposed by Aristotle himself to imply that Thales believed in a “soul of the world,” though he is careful to mark this as no more than an inference.[[87]] The doctrine of the world-soul is then attributed quite positively to Thales by Aetios, who gives it in the Stoic phraseology which he found in his immediate source, and identifies the world-intellect with God.[[88]] Cicero found a similar account of the matter in the Epicurean manual which he followed, but he goes a step further. Eliminating the Stoic pantheism, he turns the world-intellect into a Platonic demiourgos, and says that Thales held there was a divine mind which formed all things out of water.[[89]] All this is derived from the cautious statement of Aristotle, and can have no greater authority than its source. We need not enter, then, upon the old controversy whether Thales was an atheist or not. It is really irrelevant. If we may judge from his successors, he may very possibly have called water divine; but, if he had any religious beliefs at all, we may be sure they were quite unconnected with his cosmological theory.

Nor must we make too much of the saying itself that “all things are full of gods.” It is often supposed to mean that Thales attributed a “plastic life” to matter, or that he was a “hylozoist.” We have seen already how misleading this way of speaking is apt to be,[[90]] and we shall do well to avoid it. It is not safe to regard such an apophthegm as evidence for anything; the chances are that it belongs to Thales as one of the Seven Wise Men, rather than as founder of the Milesian school. Further, such sayings are, as a rule, anonymous to begin with, and are attributed now to one sage and now to another.[[91]] On the other hand, it is extremely probable that Thales did say that the magnet and amber had souls. That is no apophthegm, but something more on the level of the statement that the earth floats on the water. It is, in fact, just the sort of thing we should expect Hekataios to record about Thales. It would be wrong, however, to draw any inferences from it as to his view of the world; for to say that the magnet and amber are alive is to imply, if anything, that other things are not.[[92]]