Thales the Original Philosopher

Personal History and City State of Thales

Catherine Gaudio

Little is known about Thales because none of his documents survived, but what we do know about Thales is that he was born about 624 BC  in Mileuts an ancient Greek Ionian city located on the western coast of Asia Minor now day Turkey and Died about 546 BC in Miletos, Turkey. It is suggested by Diogenes Laertius that Thales parents were Examyes and Cleobuline and the family was linked with the royal Phoenicia family prince Cadmus. There are two contrasting stories about Thales life regrading Thales love life that are given by Diogenes. The first one is that “Thales got married and had a son named Cybisthus or Cybisthon or he adopted his nephew” holding the same name. The other stories say that Thales never married and told his mother that it was “too early to marry in his young age and later that it was too late when he grew old.

Thales was known as the first Greek Philosopher, scientist and mathematician. It has been mentioned that he may have been the teacher of Pythagoras, Thales was not just a mere thinker he also took pleasure in business and politics. The biggest business adventure that he took part in was buy all of the olive pressers in Miletus, not to gain money but to show his peers that he could elevate his status using his intelligence, as it turns out because of this incident it was cited as the first example of options trading. His political life was chiefly connected with the involvement of the Ionians in the defense of Anatolia, opposing the increase of Persians power. It is said by Diogenes Laertius that Thales acquired popularity as a counselor we he advised the Milesians not to get involved in the fight between Symmachis and Lydians, this caused Ionians to become independent.

Thales’ Physical Philosophy

Shaun Mead

Thales proposed that the primary material of all matter was Water. He observed how water can change shape to fit any container, give life to plants, change to a solid or gas, and is ubiquitous across the land. He held that natural springs was the breakdown of rocks into its liquid state and then flowing into a river or cavity. Rain is the condensation of Air into its liquid state and falling to the ground, Blood is the fluid of life that humans and animals contain and cannot live without. He then stated that the Earth rested on a bed of water which could be observed with the ships as examples since they floated even when carrying heavy objects that do not float on their own. His stance that the prime material of all things is water is not the most important part of his explanation. His philosophy is the first example of the use of natural phenomena to explain nature rather than the Gods.  His discussion of the primary substance of all things and looking to the natural world to explain the World around us was carried on by his student Anaximander and further followed by Anaximenes who both attended the School Thales founded.

He also was the first to determine that the magnetic lodestone moves iron of its own accord and was therefore “alive”. This definition of living was derived from the standard of the time that anything that can move an object of its own volition was considered alive. This was a major departure since it was the first time that Gods were not used to explain this phenomena. He discovered  Static electricity as well as its own force by observing that when Amber and furs were rubbed together they produced a static charge that could be observed by touch and sound. This moved electricity from the divine realm to the physical. His discoveries and theories laid the ground work for the creation of Natural Science and a divergence from Myths to explain the natural events around us to observable events and explanations that rely on the physical world.

A short video introducing Thales can be found here.

Thales and Geometry 

Author: Dani Kelly

During his lifetime Thales traveled to Egypt, where geometry had been flourishing due to flooding which required land to be remeasured (O’Grady). In Egypt he was able to study and learn what geometry was already known to the Egyptians and then later bring his new knowledge back to Greece. During his time in Egypt he was said to have measured the height of the pyramids by waiting until the sun caused his shadow to match his own height, he then measured the length of the pyramids shadow to determine their height (O’Grady).

Unfortunately it is unknown if Thales ever produced writings of his own, and if he did none survived to modern times. However, he is still credited with many significant discoveries which have come to form some of the basic principles of geometry. The five theorems he is credited with are-

  • A circle is bisected by any diameter.
  • The base angles of an isosceles triangle are equal.
  • The angles between two intersecting straight lines are equal.
  • Two triangles are congruent if they have two angles and one side equal.
  • An angle in a semicircle is a right angle.  

(O’Connor and Robertson).

He is credited with the first four of these discoveries thanks to the writings of the classical philosopher Proclus who quoted a now lost text, The History of Geometry by Eudemus of Rhodes to support his claims (O’Connor and Robertson). The last principle he is credited with is based on a passage from a book written in the second century CE, “Pamphile says that Thales, who learnt geometry from the Egyptians, was the first to describe on a circle a triangle which shall be right-angled, and that he sacrificed an ox (on the strength of the discovery). Others, however, including Apollodorus the calculator, say that it was Pythagoras (Laertius).”  

Even in that passage it’s shown that it’s not completely known if Thales himself came up with these principles, which certainly isn’t helped by the Greeks’ habit of attributing things to famous men, such as Athens attributing the creation of democracy to the mythological hero Theseus. Regardless, Thales is well known as the creators of this principles.


Thales and Astronomy

Written By Ryan Thimons 

Thales is considered to be one of the first actual philosophers because of his rule breaking theories that left mythological interventions and the divine world out of the natural phenomena. Although Thales didn’t write but two of his own theories much of the information we have today on his works and contributions are from Aristotle or his apprentices including Anaximander (O’Grady). Most of Thales works although mainly about the substance of water and its importance on everything was also mainly focused on the heavens and how the earth was not only round, but spherical. Thales hypothesis was backed by these three things: The Celestial bodies and where they can be viewed from, the rotation of these bodies and the annual return of them, and the shape of the solar eclipse and its relation to the earth.


After several travels, Thales would observe the position of certain stars in the sky and mark whether he could see them or not. And after not being able to track them anymore he realized that the farther north or south he went, some stars were no longer visible. But this wasn’t always the case, although he often stayed in certain areas for periods of time, he also concluded that the heavens themselves were moving around the earth in a cyclical matter, but they eventually returned. If the earth was shaped like a dome hypothetically then the stars would always be visible, and that the north and south positions wouldn’t have mattered to begin with.(O’Grady) Thales wasn’t considering just any stars though in his research, he focuses on the most important one mainly and how the earth would change positions depending on the time of year. Seasons were almost practically established in the Greek philosophy but what Thales took to another level was the solstice and the solar eclipse. Seeing as the two dates of the year where the earth would remain almost flat in terms of tilt towards the sun were quite impossible to pin point, this gave Thales the reputation for being the “Observer of the Heavens” and creating fundamental theories based off his observations. Although we can attribute the solstice and equinox to Thales, one of the more bizarre discoveries and was even written by Herodotus, was the solar eclipse. We’re still not sure even today how He did it , even with the Saros and the Exeligmos cycle (Lunar calendars over 30 months at a time) scientist are still baffled by the mystery of predicting the Solar eclipse of May 28th 585 B.C.E. (O’Grady) During that day Herodotus explains that the sky went dark and day turned into night, all accredited to the prediction of Thales. This monumental prediction has never been so exact in these parameters nor have they been recorded making Thales one of the most important and impressive philosophers of Greece, but its not to say that his works weren’t all by himself, Cicero contributed to his first theory on the celestial bodies and much of his later works were carried out by Anaximander and his students.



O’Grady, Patricia. “Thales of Miletus.” Internet Encyclopedia of Philosophy. The Flinders University of South Australia, Web. 09 Dec. 2015.

Laertius, Diogenes, and Robert Drew Hicks. Lives of Eminent Philosophers. London: W. Heinemann, Web. 01 Dec. 2015

Mark, J. J. (2009, September 02). Thales of Miletus. Retrieved December 07, 2015, from Ancient History Encyclopedia:

O’Connor, J.J., and E. F Robertson. “Thales Biography.” Thales of Miletus. School of Mathematics and Statistics, University of St Andrews Scotland, Jan. 1999. Web. 01 Dec. 2015.

O’Grady, P. (n.d.). Internet Encyclopedia of Philosophy. Retrieved December 07, 2015, from Thales of Miletus: (2012). Thales of Miletus. Retrieved December 07, 2015, from

“Thales Biography.” – Thales Childhood, Life & Timeline. N.p., n.d. Web. 08 Dec. 2015, from The Famous


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