Tales of Miletus (Meaning and Explanation)

We explain who Thales of Miletus was, the contributions he made and ideas. Furthermore, Thales' theorems and characteristics of the Miletus school.

Thales of Miletus introduced new philosophical ideas and contributions to geometry.

Who was Thales of Miletus?

Thales of Miletus was a Greek philosopher and mathematician who lived between 624 BC. C and 548 BC. c in Miletus, current territory of Türkiye. His philosophy was characterized by breaking with mythological explanations of the world and giving way to rational and logical thinking. This transformation is known as the passage from myth to logosand it is considered that this is how Western philosophy began.

Thales is located among the first physical or pre-Socratic philosophers. With him began a period that was characterized by leaving aside religious or mythological explanations regarding physical phenomena and the beginning of the world. He is often named the first philosopher of humanity, although it is necessary to clarify that this is true only for the Western world, heir of Greco-Latin thought. At the time, he was also thought of as one of the seven wise men of Greece.

One of the main themes of his study was arch or beginning of things. In classical Greek, the arch (ἀρχή) is the “beginning” or “origin” of everything that is, both in a temporal sense and as an ontological foundation. For Thales of Miletus, the constitutive principle of the world was water, and that is why he maintained that all things were formed by it. His ideas and discoveries are believed to span disciplines such as mathematics, engineering and astronomy.

In fact, He is credited with having predicted the solar eclipse that occurred in the year 585 BC. c. However, several classical, modern and contemporary philosophical schools dedicated to the history of philosophy maintain that this is not true and that, in any case, since there is no direct source of his thought, the hypothesis is unfounded.

Main ideas of Tales of Miletus

Thales' ideas can be summarized as:

For Thales, the physical universe could be explained by reason, despite the disorder it appeared. He rejected all thoughts based on the mystical or magical.
He researched the unique principle of the universe and its nature. He began wondering about the nature of things and considered that, just as a piece of a mineral could be converted into copper, all substances could be converted into others.
He considered that the first cause of everything must be material and eternal. He wondered if originally all substances could have the same appearance and if all things were actually different aspects of the same original matter.
He considered the Earth as a flat disk that was suspended over an infinite ocean covered by a light blue semisphere that was the sky.
He was the first to introduce geometry in Greece and mathematical theorems and discoveries are attributed to him. Many of them are collected in the work Items of the Greek mathematician Euclid.
According to Diogenes Laertius, a Greek historian, Thales was able to predict an eclipse and estimated the size of the moon relative to the Sun.
He is believed to have been one of the first thinkers to use deductive thinking.
He believed in a universal law (accessible through reason) that controlled and regulated everything.
He did not distinguish philosophy from science.

Life and work of Thales of Miletus

Tales of Miletus — Currently the territory of Miletus is part of Türkiye.

There is no precise information about the life of Thales of Miletus.. Most of the information comes from doxographers and compilers after the time Thales lived and thought. However, there is some information that is considered canonical, especially due to the authority of its source, such as the Metaphysics of Aristotle, where he refers to Thales and his work, especially in his capacity as a physical or naturist philosopher.

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Such He was born in a territory called Miletus, belonging to Ancient Greece. and current territory of the western coast of Türkiye. As was typical, at that time thinkers were called by their name followed by their place of birth, which is why Thales was known as Thales of Miletus.

Although his theories revolutionized thought and his ideas persist to the present, no original writings of this thinker are preserved nor is it known that he wrote any in particular. Due to this, there are no primary sources that prove the authorship of many of the discoveries attributed to Thales, and most of the data available about his life are approximate. It is believed that he was born in Miletus in 624 BC. C. and what During his youth he moved to Egypt. There he learned geometry and other sciences by studying with Egyptian priests.

To Such Several theorems and reasonings are attributed to himamong which the theorems that bear his name in the field of geometry stand out, even though, even of these, their authorship is distrusted.

The Miletus or Ionian school

The Miletus or Ionian school was founded by Thales of Miletus, together with two contemporary philosophers and inhabitants of Miletus: Anaximander and Anaximenes. This school is considered the oldest in Greece and was characterized by studying nature and the constitutive principle of the world, which is why these philosophers are known as “physicists.” The Milesian philosophers were the first to suppose that through thought answers could be found to a certain uniformity of the universe, as well as to the alternation between day and night or summer and winter, for example.

The eclipse

The other certain information we have about Thales, through Herodotus (a historian who lived 150 years later), is that Thales He predicted to the Ionians that there would be an eclipse during the battle between Lydia and Mediaon May 28, 585 BC. C. This prediction is considered one of the most important events of Antiquity.

Later studies, however, have proven that Thales could not have predicted the date of the eclipse accurately and based on a mathematical method, since his conception of the world was that of a flat planet floating above an infinite fountain of water. This could not have allowed him to carry out the calculations necessary to calculate the distance between the Earth and the Moon and the Moon and the Sun. In fact, it is Herodotus himself who gives the impression of showing that Thales he did nothing more than indicate the year of the eclipse using a calculation period known as Saros (a cycle of 223 lunar months).

Beyond the inaccuracies, the lack of first-hand knowledge and the rumors and sayings about the Ionian philosopher, the magnitude of the changes he introduced in Greek and Western philosophical thought is undeniable. The mere fact that Aristotle, the highest historiographic authority of Antiquity, mentions him in the Metaphysics as the first philosopher is reason enough to give him a privileged place in the history of Western philosophy.

Water as arché or first principle

Aristotle writes in his Metaphysics It is said that, based on his study of the nature of things, Thales came to the conclusion that all substances are derived from the same matter.. Following this statement, he established that the arch (either archéthe origin, foundation or principle of things) was water, because it was not possible for any living being (animal or plant) to have life without it. Aristotle says about this idea of the first principle:

(…) Thales, who was the first to cultivate this kind of philosophy, says that the beginning is water and, for this reason, he affirmed that the earth rests on water. His conjecture may have been born from the observation of the fact that the nourishment of all beings is moist, and that heat itself is born of moisture and lives by it, and this from which all things originate is their first principle. .
(Metaph. A, 983 b 6 et seq.)

This thought and the search for the explanation of physical phenomena through reason made Thales the “father of philosophy.” Although the philosophers of his time did not accept the idea that the origin of things was water, they did accept and agree that everything came from the same origin. For Anaximander the origin of everything was apeironfor Anaximenes it was air, for Heraclitus it was fire and for Parmenides it was being.

Mathematical contributions and Thales' theorems

It is believed that Thales introduced geometry to Greece after traveling and studying in Egypt.. Currently there are two theorems that are applied in the field of geometry and are attributed to Thales. It is believed that he used them to measure the height of the pyramids of Giza, in Egypt, from their shadows.

The following two theorems are currently considered to have been discovered by Thales or, in any case, are named in his honour:

Thales's first theorem. It states that if a parallel line is drawn on a triangle (taking one of its sides as a reference), a smaller triangle similar to the first will be obtained.
Thales' second theorem. It is applied in geometry and refers to right triangles, circles and inscribed angles. He maintains that when a triangle is formed with the diameter of a circle and two secants, the angle formed in front of the diameter measures 90°.

Other mathematical contributions attributed to Thales are:

A circle is divided into two equal parts by its diameter.
The angles that make an isosceles triangle are equal.
If two straight lines intersect, their opposite angles are equal.
In a semicircle, its inscribed angle is right.

However, these data are attributed to Thales by Diogenes and Proclus (attributing great discoveries to great thinkers was a very common practice in ancient times).

Continue with: Pythagoras

References

Guthrie, W. (1984). History of Greek Philosophy, vol. I. The first pre-Socratics and the Pythagoreans. Gredos.
Guthrie, W. (1953). The Greek philosophers. From Thales to Aristotle. FCE.
Barnabas, A. (2008). Pre-Socratic fragments, from Thales to Democritus. Alliance.
“Thales of Miletus” in Britannica.
“Thales of Miletus” in World History Encyclopedia.
“Tales of Miletus” in the Miguel de Cervantes Virtual Library.