Thales: Fragments

The founder of the Milesian school, and therefore the first man of science, was Thales;4 but all we can really be said to know of him comes from Herodotos, and the Tale of the Seven Wise Men was already in existence when he wrote. He says that Thales was of Phoenician descent, a statement which other writers explained by saying he belonged to a noble house descended from Kadmos and Agenor.5 Herodotos probably mentions the supposed descent of Thales simply because he was believed to have introduced certain improvements in navigation from Phoenicia.6 At any rate, his father's name, Examyes, lends no support to the view that he was a Semite. It is Karian, 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, while the name Thales is otherwise known as Cretan. There is therefore no reason to doubt that Thales was of pure Milesian descent, though he probably had Karian blood in his veins.7

The most remarkable statement 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.8 Now, he was quite ignorant of the cause of eclipses. Anaximander and his successors certainly were so,9 and it is incredible that the explanation should have been given and forgotten so soon. Even supposing Thales had known the cause of eclipses, such scraps of elementary geometry as he picked up in Egypt would never have enabled him to calculate one. Yet the evidence for the prediction is too strong to be rejected off-hand. The testimony of Herodotos is said to have been confirmed by Xenophanes,10 and according to Theophrastos Xenophanes was a disciple of Anaximander. In any case, he must have known scores of people who were able to remember what happened. The prediction of the eclipse is therefore better attested than any other fact about Thales whatsoever.

Now it is possible to predict eclipses of the moon approximately without knowing their true cause, and there is no doubt that the Babylonians actually did so. It is generally stated, further, that they had made out a cycle of 223 lunar months, within which eclipses of the sun and moon recurred at equal intervals of time.11 This, however, would not have enabled 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 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, though an observer at a given place might be disappointed five times out of six. Now, if we may judge from reports by Chaldaean astronomers which have been preserved, this was just the position of the Babylonians in the eighth century B.C. They watched for eclipses at the proper dates; and, if they did not occur, they announced the fact as a good omen.12 To explain what we are told about Thales no more is required. He said there would be an eclipse by a certain date; and luckily it was visible in Asia Minor, and on a striking occasion.13

The prediction of the eclipse does not, then, throw any light on the scientific attainments of Thales; but, if we can fix its date, it will give us an indication of the time at which he lived. Astronomers have calculated that there was an eclipse of the sun, probably visible in Asia Minor, on May 28 (O.S.), 585 B.C., while Pliny gives the date of the eclipse foretold by Thales as Ol. XLVIII.4 (585/4 B.C.).14 This does not exactly tally; for May 585 belongs to the year 586/5 B.C. It is near enough, however, to justify us in identifying the eclipse as that of Thales,15 and this is confirmed by Apollodoros, who fixed his floruit in the same year.16 The further statement in Diogenes that, according to Demetrios Phalereus, Thales “received the name of wise” in the archonship of Damasias at Athens, really refers to the Tale of the Seven Wise Men, as is shown by the words which follow, 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.17

The introduction of Egyptian geometry into Hellas is ascribed to Thales,18 and it is probable that he did visit Egypt; for he had a theory of the inundations of the Nile. Herodotos19 gives three explanations of the fact that this alone of all rivers rises in summer and falls in winter; but, as his custom is, he does not name their authors. The first, however, which attributes the rise of the Nile to the Etesian winds, is ascribed to Thales in the Placita,20 and by many later writers. Now, this comes from a treatise on the Rise of the Nile attributed to Aristotle and known to the Greek commentators, but extant only in a Latin epitome of the thirteenth century.21 In this the first of the 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 of Hekataios; and this conjecture is strengthened when we find that Hekataios mentioned Euthymenes.22 We may conclude that Thales really was in Egypt; and, perhaps, that Hekataios, in describing the Nile, took account, as was natural, of his fellow-citizen's views.

As to the nature and extent of the mathematical knowledge brought back by Thales from Egypt, it must be pointed out that most writers have seriously misunderstood the character of the tradition.23 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,24 one of which is that two triangles are equal when they have one side and the two adjacent angles equal. This he must have known, as otherwise he could not have measured the distances of ships at sea in the way he was said to have done.25 Here we see how all these statements arose. Certain feats in the way of measurement were traditionally ascribed to Thales, and Eudemos assumed that he must have known all the propositions these imply. But this is quite illusory. Both the measurement of the distance of ships at sea, and that of the height of the pyramids, which is also ascribed to him,26 are easy applications of the rule given by Aahmes for finding the seqt.27 What the tradition really points to is that Thales applied this empirical rule to practical problems which the Egyptians had never faced, and that he was thus the originator of general methods. That is a sufficient title to fame.

Thales appears once more in Herodotos some time before the fall of the Lydian monarchy. He is said to have urged the Ionian Greeks to unite in a federal state with its capital at Teos.28 We shall have occasion to notice more that once that the early schools of philosophy by no means held aloof from politics; and, there are many things, for instance the part played by Hekataos in the Ionian revolt, which suggest 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 to his inclusion among those worthies that the numerous anecdotes told of him in later days attached themselves to his name.29

So far as we know, Thales wrote nothing, and no writer earlier than Aristotle knows anything of him as a scientific man and a philosopher; in the older tradition he is simply an engineer and an inventor.30 It is obvious, however, that the requirements of Milesian enterprise and commerce would necessarily turn his attention to problems which we should call astronomical. He was said, we saw, to have introduced the practice of steering a ship's course by Ursa minor;31 and there is a remarkable persistence in the tradition that he tried to do something for the calendar, though the details are not sufficiently well attested to find a place here.32 No doubt he constructed a παράπηγμα like those of much later date which have been discovered at Miletos.33 The παράπηγμα was the oldest form of almanac, and gave, for a series of years, the equinoxes and solstices, the phases of the moon, the heliacal risings and settings of certain stars, and also weather predictions. Even Aristotle does not pretend to know how Thales arrived at the views he ascribes to him or by what arguments they were supported. This very reserve, however, makes it hard to doubt that he was correctly informed with regard to the few points about them he mentions, so we may venture on a conjectural restoration of his cosmology. This, of course, must be taken for just what it is worth.

The statements of Aristotle may be reduced to three:

(1) The earth floats on the water.34

(2) Water is the material cause35 of all things.

(3) All things are full of gods. The magnet is alive; for it has the power of moving iron.36

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 stuff of which all other things were transient forms. We have seen that this was the great question of the day.

Aristotle and Theophrastos, followed by Simplicius and the doxographers, suggest several explanations of this doctrine. Aristotle gives them as conjectures; it is only later writers that repeat them as if they were quite certain.37 The most probable view seems to be that Aristotle ascribed to Thales the arguments used at a later date by Hippon of Samos in support of a similar thesis.38 That would account for their physiological character. The rise of scientific medicine had made biological arguments popular in the fifth century; but, in the days of Thales, the prevailing interest was not physiological, but meteorological, and it is from this point of view we must try to understand the theory.

Now it is not hard to see how meteorological considerations 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 he saw the world-process from water and back to water again going on before his eyes. The phenomenon of evaporation naturally suggests that the fire of the heavenly bodies is kept up by the moisture they draw from the sea. Even at the present day people speak of “the sun drawing water.” Water comes down again in rain; and lastly, so the early cosmologists thought, it turns to earth. This may have seemed natural enough to men familiar with the river of Egypt which had formed the Delta, and the torrents of Asia Minor which bring down large alluvial deposits. At the present day the Gulf of Latmos, on which Miletos used to stand, is 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 to do with the rain. The “waters under the earth” were regarded as an independent source of moisture.39

The third of the statements mentioned above is supposed by Aristotle to imply that Thales believed in a “soul of the world,” though he is careful to mark this as no more than an inference.40 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.41 Cicero found a similar statement 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.42 All this is derived from Aristotle's cautious statement, and can have no greater authority than its source. We need not enter, then, on the old controversy whether Thales was an atheist or not. If we may judge from his successors, he may very possibly have called water a “god”; but that would not imply any definite religious belief.43

Nor must we make too much of the saying that “all things are full of gods.” It is not safe to regard an apophthegm as evidence, and 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.44 On the other hand, it is probable that Thales did say the magnet and amber had souls. That is no apophthegm, but more on the level of the statement that the earth floats on the water. It is just the sort of thing we should expect Hekataios to record about Thales. It would be wrong, however, to draw any inference from it as to his view of the world; for to say the magnet and amber are alive is to imply, if anything, that other things are not.

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3. Herod. i. 75. It is important for a right estimate of Ionian science to remember the high development of engineering in these days. Mandrokles of Samos built the bridge over the Bosporos for King Dareios (Herod. iv. 88), and Harpalos of Tenedos bridged the Hellespont for Xerxes when the Egyptians and Phoenicians had failed in the attempt (Diels, Abh. der Berl. Akad., 1904, p. 8). The tunnel through the hill above Samos described by Herodotos (iii. 60) has been discovered by German excavators. It is about a kilometre long, but the levels are almost accurate. On the whole subject see Diels, “Wissenschaft und Technik bei den Hellenen” (Neue Jahrb. xxxiii. pp. 3, 4). Here, as in other things, the Ionians carried on “Minoan” traditions.

4. Simplicius quotes Theophrastos as saying that Thales had many predecessors Dox. p. 475, 11). This need not trouble us; for the scholiast on Apollonios Rhodios (ii. 1248) tells us that he made Prometheus the first philosopher, which is merely an application of Peripatetic literalism to a phrase of Plato's (Phileb. 16 c 6). Cf. Note on Sources, § 2.

5. Herod. i. 170 (R. P. 9 d); Diog. i. 22 (R. P. 9). This is no doubt connected with the fact mentioned by Herodotos (i. 146) that there were Kadmeians from Boiotia among the original Ionian colonists. Cf. also Strabo, xiv. pp. 633, 636; Pausan. vii. 2, 7. These, however, were not Semites.

6. Diog. i. 23, Καλλίμαχος δ' αὐτὸν οἶδεν εὑρετὴν τῆς ἄρκτου τῆς μικρᾶς λέγων ἐν τοῖς Ἰάμβοις οὕτως—

καὶ τῆς ἁμάξης ἐλέγετο σταθμήσασθαι τοὺς ἀστερίσκους, ᾗ πλέουσι Φοίνικες.

7. See Diels, “Thales ein Semite?” (Arch. ii. 165 sqq.), and Immisch, “Zu Thales Abkunft” (ib. p. 515). The name Examyes occurs also in Kolophon (Hermesianax, Leontion, fr. 2, 38 Bgk.), and may be compared with other Karian names such as Cheramyes and Panamyes.

8. Herod. i. 74.

9. For the theories held by Anaximander and Herakleitos, see infra, §§ 19, 71.

10. Diog. i. 23, δοκεῖ δὲ κατά τινας πρῶτος ἀστρολογῆσαι καὶ ἡλιακὰς ἐκλείψεις καὶ τροπὰς προειπεῖν, ὥς φησιν Εὔδημος ἐν τῇ Περὶ τῶν ἀστρολογουμένων ἱστορίᾳ, ὅθεν αὐτὸν καὶ Ξενοφάνης καὶ Ἡρόδοτος θαυμάζει. The statement that Thales “predicted” solstices as well as eclipses is not so absurd as has been thought. Eudemos may very well have meant that he fixed the dates of the solstices and equinoxes more accurately than had been done before. That he would do by observing the length of the shadow cast by an upright (γνώμων), and we shall see (p. 47) that popular tradition ascribed observations of the kind to him. This interpretation is favoured by another remark of Eudemos, preserved by Derkyllides (ap. Theon. p. 198, 17 Hiller), that Thales discovered τὴν κατὰ τὰς τροπὰς αὐτοῦ (τοῦ ἡλίου) περίοδον, ὡς οὐκ ἴση ἀεὶ συμβαίνει. In other words, he discovered the inequality of the four seasons which is due to the solar anomaly.

11. It is wrong to call this the Saros with Souidas; for sar on the monuments always means 602=3600, the number of the Great Year. The period of 223 lunations is, of course, that of the retrograde movement of the nodes.

12. See George Smith, Assyrian Discoveries (1875), p. 409. The inscription which follows was found at Kouyunjik:—

“To the king my lord, thy servant Abil-Istar.

. . .

“Concerning the eclipse of the moon of which the king my lord sent to me; in the cities of Akkad Borsippa, and Nipur, observations they made, and then in the city of Akkad, we saw part . . . . The observation was made, and the eclipse took place.

. . .

“And when for the eclipse of the sun we made an observation, the observation was made and it did not take place. That which I saw with my eyes to the king my lord I send.” See further R. C. Thomson, Reports of the Magicians and Astrologers of Nineveh and Babylon (1900).

13. Cf. Schiaparelli, “I primordi dell' Astronomia presso i Babilonesi” (Scientia, 1908, p. 247). His conclusion is that “the law which regulates the circumstances of the visibility of solar eclipses is too complex to be discovered by simple observation,” and that the Babylonians were not in a position to formulate it. “Such a triumph was reserved to the geometrical genius of the Greeks.”

14. Pliny, N.H. ii. 53. It should be noted that this date is inconsistent with the chronology of Herodotos, but that is vitiated by the assumption that the fall of the Median kingdom synchronised with the accession of Cyrus to the throne of Persia. If we make the necessary correction, Cyaxares was still reigning in 585 B.C.

15. The words of Herodotos (i. 74), οὖρον προθέμενος ἐνιαυτὸν τοῦτον ἐν τῷ δὴ καὶ ἐγένετο, mean at first sight that he only said the eclipse would occur before the end of a certain year, but Diels suggests (Neue Jahrb. xxxiii. p. 2) that ἐνιαυτός has here its original sense of “summer solstice” (cf. Brugmann, Idg. Forsch. xv. p. 87). In that case Thales would have fixed the date within a month. He may have observed the eclipse of May 18, 603 B.C. in Egypt, and predicted another in eighteen years and some days, not later than the solstice.

16. For Apollodoros, see Note on Sources, §21. The dates in our text of Diogenes (i. 37; R. P. 8) cannot be reconciled with one another. That given for the death of Thales is probably right; for it is the year before the fall of Sardeis in 546/5 B.C., which is one of the regular eras of Apollodoros. It no doubt seemed natural to make Thales die the year before the “ruin of Ionia” which he foresaw. Seventy-eight years before this brings us to 624/3 B.C. for the birth of Thales, and this gives us 585/4 B.C. for his fortieth year. That is Pliny's date for the eclipse, and Pliny's dates come from Apollodoros through Nepos.

17. Diog. i. 22 (R. P. 9), especially the words καθ' ὃν καὶ οἱ ἑπτὰ σοφοὶ ἐκλήθησαν. The story of the tripod was told in many versions (cf. Diog. i. 28-33 ; Vors. i. p. 226 sqq.). It clearly belongs to the Delphian Tale of the Seven Wise Men, which is already alluded to by Plato (Prot. 343 a, b). Now Demetrios of Phaleron dated this in the archonship of Damasias at Athens (582/1 B.C.), and the Marmor Parium dates the restoration of the ἀγὼν στεφανίτης at Delphoi in the same year, and also identifies it with that of Damasias (cf. Jacoby, p. 170, n. 12).

18. Proclus, in Eucl. I. p. 65, Friedlein (from Eudemos).

19. Herod. ii. 20.

20. Aet. iv. 1.1 (Dox. p. 384).

21. Dox. pp. 226-229. The Latin epitome will be found in Rose's edition of the Aristotelian fragments.

22. Hekataios, fr. 278 (F.H.G. i. p. 19).

23. See Cantor, Vorlesungen über Geschichte der Mathematik, vol. i. pp. 12 sqq.; Allman, “Greek Geometry from Thales to Euclid” (Hermathena, iii. pp. 164-174).

24. Proclus, in Eucl. pp. 65, 7; 157, 10; 250, 20; 299, 1; 352, 14 (Friedlein). Eudemos wrote the first histories of astronomy and mathematics, just as Theophrastos wrote the first history of philosophy.

25. Proclus, p. 352, 14, Εὔδημος δὲ ἐν ταῖς γεωμετρικαῖς ἱστορίαις εἰς Θαλῆν τοῦτο ἀνάγει τὸ θεώρημα (Eucl. 1.26) τὴν γὰρ τῶν ἐν θαλάττῃ πλοίων ἀπόστασιν δι' οὗ τρόπου φασὶν αὐτὸν δεικνύναι τούτῳ προσχρῆσθαί φησιν ἀναγκαῖον.

26. The oldest version of this story is given in Diog. i. 27, ὁ δὲ Ἱερώνυμος καὶ ἐκμετρῆσαί φησιν αὐτὸν τὰς πυραμίδας, ἐκ τῆς σκιᾶς παρατηρήσαντα ὅτε ἡμῖν ἰσομεγέθης ἐστίν.. Cf. Pliny, H. Nat. xxxvi. 82, mensuram altitudinis earum deprehendere invenit Thales Milesius umbram metiendo qua hora par esse corpori solet. (Hieronymos of Rhodes was contemporary with Eudemos.) This need imply no more than the reflexion that the shadows of all objects will be equal to the objects at the same hour. Plutarch (Conv. sept. sap. 147 a) gives a more elaborate method, τὴν βακτηρίαν στήσας ἐπὶ τῷ πέρατι τῆς σκιᾶς ἣν ἡ πυραμὶς ἐποίει γενομένων τῇ ἐπαφῇ τῆς ἀκτῖνος δυοῖν τριγώνων, ἔδειξας ὃν ἡ σκιὰ πρὸς τὴν σκιὰν λόγον εἶχε, τὴν πυραμίδα πρὸς τὴν βακτηρίαν ἔχουσαν.

27. See Gow, Short History of Greek Mathematics, § 84.

28. Herod. i. 170 (R. P. 9 d).

29. The story of Thales falling into a well (Plato, Theaet. 174 a) is nothing but a fable teaching the uselessness of σοφία; the anecdote about the “corner” in oil (Ar. Pol. A, 11. 1259 a 6) is intended to inculcate the opposite lesson.

30. Cf. Aristophanes, Clouds 180 (after a burlesque description of how Sokrates provided himself with a cloak) τί δῆτ' ἐκεῖνον τὸν Θαλῆν θαυμάζομεν; Birds 1009 (of Meton's town-planning, ἅνθρωπος Θαλῆς). Plato's way of speaking is remarkable. Cf. Rep. 600a ἀλλ' οἷα δὴ εἰς τὰ ἔργα σοφοῦ ἀνδρὸς πολλαὶ ἐπίνοιαι καὶ εὐμήχανοι εἰς τέχνας ἤ τινας ἄλλας πράξεις λέγονται, ὥσπερ αὖ Θάλεώ τε πέρι τοῦ Μιλησίου καὶ Ἀναχάρσιος τοῦ Σκύθου.

31. See p. 41, n. 2.

32. If he tried to introduce the year of 360 days and the month of 30 days, he may have learnt that in Egypt.

33. For the Milesian παραπήγματα see Rehm, Berl. Sitzungsber., 1893, p. 101 sqq., 752 sqq.

34. Ar. Met. A, 3. 983 b 21 (R. P. 10); De caelo, B, 13. 294 a 28 (R. P. 11).

35. Met. A, 3. 983 b 21 (R. P. 10). We must translate ἀρχή here by “material cause,” for τῆς τοιαύτης ἀρχῆς means τῆς ἐν ὕλης εἴδει ἀρχῆς (b 7). The word, then, is used here in a strictly Aristotelian sense. Cf. Introd. p. ii, n. 3.

36. Arist. De an. A, 5. 411 a 7 (R. P. 13); ib. 2. 405 a 19 (R. P. 13 a). Diog. i. 24 (R. P. ib.) adds amber.

37. Met. A, 3. 983 b 22 ; Aet. i. 3, 1 ; Simpl. Phys. p. 36, 10 (R. P. 10, 12, 12 a). The last of Aristotle's explanations, that Thales was influenced by cosmogonical theories about Okeanos and Tethys, has strangely been supposed to be more historical than the rest, whereas it is merely a fancy of Plato's taken literally. Plato says (Theaet. 180 d 2; Crat. 402 b 4) that Herakleitos and his predecessors (οἱ ῥέοντες) derived their philosophy from Homer (Il. xiv. 201), and even earlier sources (Orph. frag. 2, Diels, Vors. 66 B 2). In quoting this suggestion, Aristotle refers it to “some”—a word which often means Plato—and he calls the originators of the theory παμπαλαίους, as Plato had done (Met. A, 3. 983 b 28; cf. Theaet. 181 b 3). This is how Aristotle gets history out of Plato. See Note on Sources, § 2.

38. Compare Arist. De an. A, 2. 405 b 2 (R. P. 220) with the passages referred to in the last note. We now know that, though Aristotle declines to consider Hippon as a philosopher (Met. A, 3. 984 a 3; R. P. 219 a), he was discussed in the Peripatetic history of medicine known as Menon's Iatrika. See §185.

39. The view here taken most resembles that of the “Homeric allegorist” Herakleitos (R. P. 12 a). That, however, is also a conjecture, probably of Stoic, as the others are of Peripatetic, origin.

40. Arist. De an. A, 5. 411 a 7 (R. P. 13).

41. Aet. i. 7, 11=Stob. i. 56 (R. P. 14). On the sources here referred to, see Note on Sources, §§ 11, 12.

42. Cicero, De nat. d. 1. 25 (R. P. 13 b). On Cicero's source, see Dox. pp. 125, 128. The Herculanean papyrus of Philodemos is defective at this point, but it is not likely that he anticipated Cicero's mistake.

43. See Introd. § IX.