Thales

The title of this article is ambiguous. Further meanings are listed under Thales (disambiguation) .

Depiction of Thales from a Swedish lexicon, 1875

Thales of Miletus ( ancient Greek Θαλῆς ὁ Μιλήσιος Thalḗs ho Milḗsios ; * probably around 624/23 BC in Miletus ; † between 548 and 544 BC there) was a pre-Socratic natural philosopher, geometer and astronomer of archaic Greece .

Thales probably left no writings. The transmission took place through other authors of the ancient world . Since legends were formed around him early on, you can usually not rely on details known about him. However, a rough picture can be drawn.

Accordingly, he was politically active in his hometown of Miletus and was one who was admired for his great wisdom . He was seen as one of the Seven Wise Men and as the founder of Greek natural philosophy , astronomy and geometry .

Life

Thales, whose parents were Examyes and Kleobuline, lived in the city of Miletus on the west coast of Asia Minor. Whether or not he was of Phoenician origin is controversial. According to Diogenes Laertios, he (or at least his mother) came from the noble family of the Thelids. However, it is also believed that Thales' mother was of Greek and his father was of Carian descent.

Thales, as reported in the Chronicle of Apollodorus of Athens (approx. 180–110 BC), probably appeared in the 39th Olympiad, around the year 624/623 BC. And died at the age of 78 in the 58th Olympiad, i.e. between 548 and 544.

There is conflicting information about Thales' family situation. Possibly he had a wife and a child, according to other statements he was unmarried and adopted his sister's son.

Diogenes Laertios reports that Thales was not instructed by anyone apart from the Egyptians and the priests. He quotes Pamphile as saying that Thales learned geometry from the Egyptians . Presumably he spent some time doing research in Egypt (and also Crete ), where he learned from priests and astronomers in the fields of mathematics and astronomy.

Political activity

There are various indications that Thales had some political influence in Miletus. At least since Plato , Thales was usually mentioned as the first of the seven wise men, who usually included statesmen like the famous Athenian lawgiver Solon .

There are also reports that Thales emerged as a political advisor: Herodotus reported, for example, that Thales had given the Ionians the good advice to “build a common meeting house in Teos, because Teos is the center of Ionia, but the other cities should are still regarded as independent municipalities ". This seems implausible , since this centralistic idea belongs more to Pericles than to Thales.

In addition, says Diogenes Laertius, he had advised the Milesians, an alliance with Croesus , the Lydian to take -König what the Milesians in view of the victory of Cyrus , the Persian 've -königs, later rescued. This contradicts the anecdote in Herodotus that Thales diverted the Halys River so that Kroisos' army could cross it.

The individual reports may have been fabricated. On the whole, however, it seems plausible that Thales played a role in Milesian politics.

Philosophy and science

Natural philosophy

Water as archḗ

Long before Thales, water, along with other terms, was a term that was used in the cosmogonies of the ancient Orient to explain the origin of the world. The idea of ​​a cosmic primeval ocean, within which heaven and earth are said to have arisen, can already be found under the name Apsu in Sumerian mythology and from there probably reached both Babylonia and ancient Egypt . Also in the Iliad , which was written in the 8th century BC. Was composed by Homer , the river god Okeanos is said to be the "origin of the gods" and the "origin of everything." The poet Alkman wrote a history of the creation of the world, starting with the waters. It can be assumed that some of these ancient ideas influenced Thales. In any case, this has gone down in the history of philosophy because it is said to have designated water as the beginning or source of all things:

A Thales memorial in Deggendorf

"Thales [...] refers to the [...] origin [ archḗ ] the water [hýdōr]. The land, too, he therefore taught, rest on the water. The reason for this view was probably the observation that the food of all beings is moist, that the warmth itself arises from it and lives from it; but from what everything becomes, that is the origin of everything. If this was one reason for his opinion, another was probably the fact that the seeds of all beings are of a moist nature, but that water constitutes the principle for the nature of moisture. Now some are of the opinion that the ancients, who lived long before the present age and were the first to think in mythical form, would have harbored the same assumption about substance. These named Okeanos and Tethys as the originators of the world and water as that where the gods swear. […] Whether such an original view of the substance can really be found in it may not perhaps be discernible. In any case, Thales is reported to have put forward this view of the highest cause. "

- Aristotle : Metaphysica 983b20f.

After Aristotle, Thales was the first philosopher to pose the question of the origin of all things. Aristotle differentiates the views of the pre-Socratics according to the number and nature of the assumed origin of all things ( archḗ ). Thales did not assume several origins - like Empedocles , who proceeded from the four origins of fire, water, air and earth - but only one that was also "material" in nature, i.e. not "immaterial" such as "the unlimited" of his Student's Anaximander . Hippolytus of Rome and Diogenes Laertios also report something similar to Aristotle's , with Hippolytus of Rome also mentioning the theology and astronomy of the valley as well as an anecdote in the following quote:

“Thales from Miletus, one of the seven wise men, is said to have dealt first with natural science. He maintained that the origin and end of the universe was water; for the universe consists of water, be it in a solid or in a liquid state, and it floats on the water; from this come the earthquakes, the alternation of winds and the movements of the stars; everything is in suspension and in flux, as is the nature of the first cause of becoming; that which has neither beginning nor end is God. Thales also devoted himself to teaching and research about the stars and is thus the first founder of the relevant science for the Greeks. As he was looking up at the sky one day to be able to observe things closely above, as he said, he fell into a well. A maid named Thratta laughed at him and said: "Since he wants to see things in heaven, he overlooks what is at his feet." Thales lived in the time of Croesus. "

- Hippolytus of Rome : Refutatio omnium haeresium I, 1

"Thales taught that the origin of all things is water."

- Diogenes Laertios : I, 27

See also : Four-Element-Doctrine

miscellaneous

Aristotle reports that Thales explained the rest of the earth by saying that the earth floats on water.

Thales is said to have named the Etesien as the reason for the annual flooding of the Nile , because these summer winds, which are opposite to the northern direction of flow of the Nile, would prevent it from flowing into the Mediterranean.

mathematics

Illustration of the Thales theorem

Here the sun is positioned in such a way that the shadow of a rod (B) is just as long as the rod itself (A) and the length of the shadow of a pyramid plus half its side length (results in C) is just as long as the height of the pyramid ( D). Thales measured the shadow and the side length of the pyramid and was able to say how high it was.

Diogenes Laertios gave us two mathematical insights from the valley. Pamphile said that Thales was “the first to enter the right-angled triangle in the circle.” Diogenes Laertios usually interprets this passage in such a way that the sentence of Thales is meant here . Thales's theorem is a mathematical theorem according to which a triangle, one side of which is a diameter of its circumference, is a right-angled triangle. But one can also interpret the point in such a way that Thales drew the right-angled triangle with the same area as the circle, with 3 resulting as an approximation for the number of circles . The second point is: "After Hieronymus of Rhodes , he has the height of the pyramids [...] measured because our shadow length of body size is the same." This measurement method can be a later than early precursor radiation law be considered, but the truth of the traditional office is controversial. For example, the measurement method described is not suitable for measuring the height of every pyramid (some have an angle of inclination that is too flat ); with a suitable one, the top of the pyramid shadow was only exactly vertically above when the sun was in a favorable position, i.e. one or two days a year a pyramid edge, so that this was directly measurable. This method was hardly practical for measuring pyramid heights and was also not particularly impressive, because the Egyptians were able to calculate the height of a pyramid without difficulty.

Proklos gives further mathematical knowledge of Thales in his commentary on Euclid's elements : “Thales is said to have proven first that the circle is bisected by the diameter.” Proklos continues: “It is said that he was the first to know and said that in every isosceles triangle the angles at the base line are the same, whereby in an ancient way the same [ἴσας, d. H. dimensionally similar] angle similar [ὁμοίας, d. H. gestaltiform]. ”According to Eudemos , Thales is said to have first found that vertex angles are the same, but only Euclid considered a proof necessary. Another passage reads: “In his history of geometry, Eudemos traces this proposition [the third congruence proposition ] back to Thales. He says the method by which he calculated the distance of the ships at sea must necessarily be based on the use of this theorem. ”However, it is still unclear how Thales was supposed to have done this; ancient measuring methods were hardly suitable for this. Eudemos also only assumed that Thales knew this sentence.

astronomy

Herodotus reports that Thales correctly predicted the year of an eclipse that suddenly occurred during a battle between Lydians and Medes . This is often interpreted to mean a total solar eclipse. Retrospectively, it was calculated that the most likely solar eclipse on May 28, 585 BC. BC to Herodotus few details match. Herodotus quote leaves open what kind of eclipse it was. Total solar eclipses are extremely rare, and atmospheric eclipses are much more likely. With the knowledge available at Thales' time, it was also not possible to calculate the time of a solar eclipse in advance. It is likely that Thales predicted something else, which Herodotus subsequently identified with the eclipse at that battle.

Diogenes Laertios reported the following about the astronomy of the valley:

"Some authors claim that he was the first to do astronomy, predict solar eclipses and set the solstices."

- Diogenes Laertios : I, 23

“He also first determined the path of the sun from turn to turn, and according to others, the ratio of the sun and moon diameters to the respective orbit circumference as 1: 720. He was the first to refer to the last day of the month as "the thirtieth" and to discuss natural-theoretical problems. "

- Diogenes Laertios : I, 24

"He is said to have introduced the seasons and divided the year into 365 days."

- Diogenes Laertios : I, 27

The moon crater Thales is named after him.

technology

A possible engineering achievement by the valley was also reported. So he had at least partially diverted the river Halys so that the army of Kroisos could cross it. Herodotus doubted this and had the army cross the river on existing bridges.

Anecdotes

Two anecdotes about Thales in particular have become known. According to the first, based on his astronomical knowledge, he is said to have forecast a large olive harvest and then invested profitably in oil presses:

“Because of his poverty he was accused [...] that philosophy was a useless occupation. Since he had now recognized as a result of his star gazing that there would be a rich olive harvest, he is said to have deposited down payments for all the oil presses in Miletus and Chios during the winter [...] and, since no one objected, rented them for a small amount. But when the right moment came, and at the same time and suddenly there was a great need for oil presses, he rented them out on his terms and made a lot of money in the process. He has proven that it is easy for philosophers to get rich if they only want, but that is not what they strive for. "

- Aristotle : Politica 1259a

According to the second, he is said to have been mocked by a maid for falling into a well while looking at the stars:

“Thales […] fell into a well while studying the stars and looking up. A witty and charming Thracian maid is said to have mocked him because, although he desires to see things in heaven, he misses what lies at his feet. "

- Plato : Theaetetus 174a

A frequently received anecdote is that Thales received a tripod , which was intended as a prize for the wisest of all people. There are some conflicting versions of this story.

Lore

Almost all researchers assume that Thales was not a writer. What is known of him has been passed down through other ancient authors. One of the main sources of his life and work is the ancient writer Diogenes Laertios , who, however, lived about 800 years after Thales. Even this was dependent on sometimes contradicting sources. Earlier authors who report on Thales are the historian Herodotus as well as the philosophers Plato and especially Aristotle .

Honor

The plant genus Thalesia Bronner from the grapevine family (Vitaceae) is named after Thales .

Source collections

• Hermann Diels , Walther Kranz (ed.): The fragments of the pre-Socratics . 6th edition. Volume 1, Berlin 1951, pp. 67–81 (only partially with German translation; numerous new editions).
• M. Laura Gemelli Marciano (Ed.): The pre-Socratics. Volume 1, Artemis & Winkler, Mannheim 2007, ISBN 978-3-7608-1735-4 , pp. 6–31 (with German translation, explanations and introduction to life and work).
• Jaap Mansfeld (ed.): The pre-Socratics. Volume 1, Reclam, Stuttgart 1983, pp. 44–55 (only German translation; numerous new editions).
• Georg Wöhrle (Ed.): Thales (= Traditio Praesocratica. The Milesier. Volume 1). De Gruyter, Berlin 2009 (with German translation).

literature

Overview representations in manuals

• Dmitri Panchenko: Thalès de Milet. In: Richard Goulet (ed.): Dictionnaire des philosophes antiques. Volume 6, CNRS Éditions, Paris 2016, ISBN 978-2-271-08989-2 , pp. 771-793
• Hellmut Flashar et al. (Ed.): Early Greek Philosophy (= Outline of the History of Philosophy. The Philosophy of Antiquity. Volume 1). Half volume 1, Schwabe, Basel 2013, ISBN 978-3-7965-2598-8 , pp. 182–184 ( Thomas Schirren : Biographie des Thales) and pp. 237–262 (Niels Christian Dührsen: work, teaching, reception).
• James Longrigg: Thales . In: Charles Coulston Gillispie (Ed.): Dictionary of Scientific Biography . tape 13 : Hermann Staudinger - Giuseppe Veronese . Charles Scribner's Sons, New York 1976, p. 295-298 .
• R. Flood, R. Wilson: Thales. In: The Great Mathematicians , Arcturus, London 2012, ISBN 978-1-84858-843-1 , pp. 30-33

Overall presentations and investigations

• Hans Blumenberg : The Laughter of the Thracian. A prehistory of theory. Frankfurt 1987.
• Helmuth Gericke : Mathematics in Antiquity and the Orient. Springer, Berlin 1984.
• Willy Hartner : Eclipse Periods and Thales' Prediction of a Solar Eclipse. Historic Truth and Modern Myth. In: Centaurus. Volume 14, 1969, pp. 60-71
• Pietro Mazzeo: Talete, il primo filosofo. Editrice Tipografica, Bari 2010.
• Bruno Snell : The news about the teachings of Thales and the beginnings of the Greek history of philosophy and literature. In: Philologus . Volume 96, 1944, pp. 170 ff. (Also in: Bruno Snell: Gesammelte Schriften. Vandenhoeck and Ruprecht, Göttingen 1966, pp. 119–128; as well as in: Carl Joachim Classen (ed.): Sophistik. Wissenschaftliche Buchgesellschaft, Darmstadt 1976, pp. 478-490).

reception

• Gero Guttzeit: Thales. In: Peter von Möllendorff , Annette Simonis, Linda Simonis (eds.): Historical figures of antiquity. Reception in literature, art and music (= Der Neue Pauly . Supplements. Volume 8). Metzler, Stuttgart / Weimar 2013, ISBN 978-3-476-02468-8 , Sp. 971-976.

Web links

• Patricia O'Grady:  Thales. In: J. Fieser, B. Dowden (Eds.): Internet Encyclopedia of Philosophy .
• John J. O'Connor, Edmund F. Robertson :  Thales of Miletus. In: MacTutor History of Mathematics archive . .
• Karl Bormann: Thales of Milet. In: UTB online dictionary philosophy.
• Diogenes Laertios: Lives and Opinions of Famous Philosophers , translated and explained by Otto Apelt , Volume I - VI, Leipzig 1921

Footnotes

1. ↑ Diogenes Laertios I, 22.
2. ↑ Georg Wöhrle: Thales, a Phoenician? In: Mnemosyne . Volume 68, No. 3, 2015, pp. 470-478, doi: 10.1163 / 1568525X-12341649 .
3. ↑ Alexander Herda: Greek (and our) views of the Karians. In: Alice Mouton, Ian Rutherford , Ilya Yakubovich (Eds.): Luwian Identities. Culture, Language and Religion Between Anatolia and the Aegean. Brill, Leiden and Boston 2013, p. 437.
4. ↑ Thomas Schirren, Georg Rechenauer: Biography. In: Hellmut Flashar et al. (Ed.): Early Greek Philosophy (= The Philosophy of Antiquity. Volume 1). Schwabe Verlag, Basel 2013, ISBN 978-3-7965-2598-8 , p. 175.
5. ↑ Thomas Schirren, Georg Rechenauer: Biography. In: Hellmut Flashar et al. (Ed.): Early Greek Philosophy (= The Philosophy of Antiquity. Volume 1). Schwabe Verlag, Basel 2013, ISBN 978-3-7965-2598-8 , p. 182 f.
6. ↑ Diogenes Laertios I, 25 f.
7. ↑ ^{a b} Diogenes Laertios I, 27.
8. ↑ Diogenes Laertios I, 24.
9. ↑ Diogenes Laertios I, 24; I, 27; I, 43.
10. ↑ Plato, Protagoras 342e ff.
11. ↑ Georg Wöhrle (Ed.): Thales (= Traditio Praesocratica. The Milesier. Volume 1). De Gruyter, Berlin 2009, p. 17.
12. ↑ Herodotus, Historiae I, 170; German translation by Georg Wöhrle in: the same (Ed.): Thales (= Traditio Praesocratica. The Milesier. Volume 1). De Gruyter, Berlin 2009, p. 35.
13. ↑ M. Laura Gemelli Marciano (Ed.): The pre-Socratics. Volume 1, Artemis & Winkler, Mannheim 2007, ISBN 978-3-7608-1735-4 , p. 22.
14. ↑ Diogenes Laertios I, 25.
15. ↑ Herodotus , Historiae I, 75.
16. ↑ See also Diogenes Laertios I, 36.
17. ↑ Homer , Iliad 14,201.
18. ↑ Homer , Iliad 14,246.
19. ↑ Jaap Mansfeld (Ed.): Die Vorsokratiker I. Greek / German, Reclam, Stuttgart 1998, p. 40.
20. ↑ Aristotle, Metaphysica 983b20f.
21. ↑ Aristotle, Metaphysica 983b; see also Physica 184b.
22. ↑ Aristotle , De caelo II, 13,294a28-b6; see Aristotle, Metaphysica 983b20.
23. ↑ Herodot , Historiae II, 20 (without mentioning Thales'); Diogenes Laertios I, 37.
24. ↑ Diogenes Laertios I, 24; German translation by Georg Wöhrle in: the same (Ed.): Thales (= Traditio Praesocratica. The Milesier. Volume 1). De Gruyter, Berlin 2009, p. 197.
25. ↑ Cf. Fritz Krafft : History of the Natural Sciences I , Rombach, Freiburg 1971, p. 90 f.
26. ↑ Helmuth Gericke : Mathematics in antiquity and the Orient. P. 75.
27. ↑ Helmuth Gericke : Mathematics in antiquity and the Orient. P. 60 f.
28. ↑ Proklos , In primum Euclidis elementorum librum commentarii 157.10 f. (= Hermann Diels, Walther Kranz (ed.): The fragments of the pre-Socratic 11A20).
29. ↑ Proklos , In primum Euclidis elementorum librum commentarii 250, 22 f. (= Hermann Diels, Walther Kranz (ed.): The fragments of the pre-Socratic 11A20).
30. ↑ Proklos , In primum Euclidis elementorum librum commentarii 299.1 (= Hermann Diels, Walther Kranz (ed.): The fragments of the pre-Socratic 11A20).
31. ↑ Proklos , In primum Euclidis elementorum librum commentarii 352, 14 f. (= Hermann Diels, Walther Kranz (ed.): The fragments of the pre-Socratic 11A20).
32. ↑ Helmuth Gericke : Mathematics in antiquity and the Orient. P. 76 f.
33. ↑ Herodotus , Historiae I, 74.
34. ↑ Otta Wenskus : The alleged prediction of a solar eclipse by Thales of Miletus. Why this legend persists and why it is important not to believe it. In: Hermes . Volume 144, No. 1, 2016, pp. 2-17.
35. ↑ Diogenes Laertios I, 38.
36. ↑ Herodotus , Historiae I, 75.
37. ↑ German translation by Georg Wöhrle in: the same (Ed.): Thales (= Traditio Praesocratica. The Milesier. Volume 1). De Gruyter, Berlin 2009, p. 49.
38. ↑ See Diogenes Laertios I, 26.
39. ↑ German translation by Georg Wöhrle in: the same (Ed.): Thales (= Traditio Praesocratica. The Milesier. Volume 1). De Gruyter, Berlin 2009, p. 40.
40. ↑ Diogenes Laertios I, 27-33.
41. ↑ Niels Christian Dührsen: Thales. In: Hellmut Flashar et al. (Ed.): Early Greek Philosophy (= The Philosophy of Antiquity. Volume 1). Schwabe Verlag, Basel 2013, ISBN 978-3-7965-2598-8 , p. 239.
42. ↑ Niels Christian Dührsen: Thales. In: Hellmut Flashar et al. (Ed.): Early Greek Philosophy (= The Philosophy of Antiquity. Volume 1). Schwabe Verlag, Basel 2013, ISBN 978-3-7965-2598-8 , p. 237.
43. ↑ Lotte Burkhardt: Directory of eponymic plant names - extended edition. Part I and II. Botanic Garden and Botanical Museum Berlin , Freie Universität Berlin , Berlin 2018, ISBN 978-3-946292-26-5 doi: 10.3372 / epolist2018 .