Thales of Miletus: The Father of Western Philosophy (Facts & Bio)

A philosopher, astronomer and legendary mathematician, the ancient Greek philosopher Thales of Miletus set the basis of Western thought.

Mar 22, 2021By Antonis Chaliakopoulos, MSc Museum Studies, BA History & Archaeology
Thales, by Wilhelm Meyer, 1875; with Thales, by Jean Couvay after Claude Vignon, ca. 1639-1640

Thales of Miletus was a Greek philosopher and one of the seven sages of antiquity. Aristotle considered him to be the first philosopher and his philosophical predecessor. Today, Thales is widely accepted as the first philosopher in the Western tradition. Although some of his concepts, like the idea that everything is made of water, seem out of place in the 21st century, Thales was an ingenious figure that changed the ancient world through his work in geometry, mathematics, astronomy, and, of course, philosophy.


The Life of Thales of Miletus

Thales, from the Nuremberg Chronicle, Michel Wolgemut and Wilhelm Pleydenwurff, 1493


Thales was the son of Examyas and Cleobulina and was born in the Greek Ionian city of Miletus in Asia Minor at around 620 BCE. He belonged in one of the noble families of Miletus with possible Phoenician origins.


Not much is known about his life, but he was revered as one of the wisest Greeks of all time. He was included in the list of the seven sages of antiquity by Plato and considered to be the first philosopher by Aristotle. Traditionally, Thales is always listed as the first Presocratic philosopher. He is part of the group of the Milesian philosophers including Anaximander and Anaximenes who were his students and continuers of his thinking. In addition, due to his belief that everything derives from one and only element, water, he is also a monist philosopher just like the rest of the Milesians as well as the Ionian Greek philosopher Heraclitus.


Like most of the Presocratic philosophers, Thales was not simply a philosopher but rather a jack of all trades. He was a mathematician, an astronomer, and a mechanic. This was not something unusual. Science, theology, and philosophy were still deeply interconnected. At the time, a philosopher was a term signifying someone who loved wisdom and knowledge in all its forms. The main difference of a presocratic Greek philosopher, like Thales, from an Egyptian priest of Osiris, a Persian magus, or a Buddhist mystic, was the attempt to explain natural phenomena using natural principles. While Thales’ view that everything derives from water can be traced back to Egyptian and Semitic creation myths, his theory was an attempt at explaining the material world using natural, and not theological, principles.


Diogenes Laertius who lived in the third century CE attributes the famous Delphic maxim “know thyself” to Thales, although the ancients disagreed on the matter.

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In general, ancient sources disagreed on whether Thales of Miletus ever wrote a book. In any case, the key ideas of his thought were preserved through the work of later philosophers and scholars.


His Death

The astrologer that fell into a well, illustration by Jean Ignace Isidore Gérard, before 19th century


Thales’ death is placed in the 550s and there are two different versions of how he died. According to Apollodorus, he died of a heat stroke while watching the Olympic Games. However, Plato records that Thales was studying the stars of the night sky when he fell into a well. This story had a didactic value for the ancients warning them against spending too much time philosophizing, without caring about earthly matters.


However, the story could be a made-up legend. This was not uncommon in antiquity. Especially when it came to significant philosophers, politicians, and other influential personalities, the Greeks loved making up fake death stories that corresponded to the life or teachings of the deceased. Sometimes these stories were didactic and other times simply mean. In Thales’ case, it was probably a combination of the two. In the story with the well, Thales died because he lost contact with the real world after being absorbed in his pursuit of higher knowledge. Making him drown in the well was also a fun way of dismissing his theory that everything is made of water.


Thales’ Many Scientific Advancements

Thales causing the river to flow on both sides of the Lydian army, by Salvator Rosa, ca. 1663-4, Art Gallery of South Australia


Thales of Miletus was not simply a theorist. He was a man who put his theoretical understanding of the world into practice. According to Herodotus, he had helped the army of King Croesus of Lydia cross the river Halys by digging a dam that divided the river into two passable straits.


As for his knowledge in Geometry and Mathematics, Thales became a symbol of the inventive man and most famously counted the height of the Great Pyramid of Giza using its shadow. He also measured the distance of ships at sea and was attributed with five theorems including the one known as the “Thales Theorem.”


Solar Eclipse


His work on astronomy was also significant. His greatest and most well-known achievement was the prediction of the solar eclipse of May 28, 585 BC. He also observed and studied constellations; a feat that would be useful in the navigation of the sea. His third most important astronomical achievement was the determination of the sun’s course from solstice to solstice.


Thales Had Travelled to Egypt

Thales, by Jacques de Gheyn III, 1616, British Museum


“Thales… first went to Egypt and hence introduced this study [geometry] into Greece. He discovered many propositions himself, and instructed his successors in the principles underlying many others, his method of attack being in some cases more general, in others more empirical.”
Proclus quoted by Thomas Little Heath


It was quite common amongst the Greeks to credit their wisest with having visited Egypt. Pythagoras, Solon, and Plato are among the most notable examples. However, in the case of Thales of Miletus, it seems that he really visited the land of the Nile as many of his achievements, like the measuring of the pyramids’ height, were set in Egypt.


Even if Thales’ visit never occurred, the legend may still point to the origins of the philosopher’s ideas. Thales was surely aware of Egyptian views about the cosmos and its creation but he managed to adapt them in a unique, unprecedented manner that led to the birth of philosophical thinking.


In addition, Geometry had originated in Egypt and Egyptian mathematical knowledge was among the most advanced in the world. Without a doubt, this knowledge passed down to Thales who became known as the one who introduced Geometry to Greece.


Thales and Monopoly

Illustration showing how the ancient Greeks may have harvested olives for oil, by H.M. Herget, Natural Geographic Image Collection

“…it is easy for philosophers to be rich if they choose, but this is not what they care about.”
Aristotle, Politics 1259a


In a story told by Aristotle, Thales of Miletus provided one of the best arguments in defense of the life of a philosopher. In this story, Thales observed the celestial bodies and managed to predict that the next crop of olives would be unusually productive. He then invested in the olive presses of Miletus and Chios and, when the olives were ready to be turned to olive oil, he controlled the rate in which they were brought. This way he made a huge profit.


However, according to Aristotle, Thales did not do that in order to make money but to prove that a philosopher could live a wealthy life if they chose to. This way Thales gave an answer to everyone who called his profession useless and made fun of his poverty. The Milesian proved that a philosopher is not poor by fate but by choice at the same time signaling that there is a path of knowledge and spirituality offering higher satisfaction than the path of material wealth.


Aristotle was not convinced that this story was real. He thought that because of Thales’ wisdom, people attributed him with the tactic of monopolizing a market.


The Philosophy of Thales

Thales, by Jean Couvay after Claude Vignon, ca. 1639-1640, British Museum


As already mentioned before, Thales of Miletus is considered the first philosopher in the Western canon. His students Anaximander and Anaximenes did not follow his ideas exactly but maintained a similar direction. Since these three were born in Miletus, they are always grouped together as the Milesians.


Many also categorize Thales as an Ionian monist philosopher alongside his Milesian students and Heraclitus, the obscure philosopher from Ephesus that held that everything is made of fire and that “everything flows.”


There are many types of monism but Thales’ philosophy can be classified as substance and materialist monism. Substance monism is the idea that everything in the world can be traced back to a single substance. For Thales of Miletus, this was water. Since he also appeared to believe that matter, in the form of water, was above abstract ideas, like the soul, he was also a materialist. The monism of Thales does not mean that Thales did not recognize the existence of other substances. It rather means that he held that the primary source of everything was to be found in water. Although this sounds preposterous, in a sense, Thales was onto something.


Water, the Origin of Everything

The monk by the sea, by Caspar David Friedrich, 1808-1810, Alte Nationalgallerie


“Thales the Milesian doth affirm that water is the principle whence all things in the universe spring.” Pseudo-Plutarch, Placita Philosophorum 1.3


Thales believed that the world was made of water and that at some point everything would return to water.


Today, we understand that water is the universal solvent and, as far as we can tell, a necessary component for the existence of life. Now imagine being a man looking for answers to the nature of things 2,600 years ago. As you are trying to unravel the mystery of existence, you make the following observation; water is everywhere. You find a vast ocean, rivers, lakes, rain, snow, and observe that every living organism depends on this one substance called water. After all this, you observe water in all its forms; liquid, solid, and gas. Water is absorbed into the earth, and earth into the sea.


This doesn’t stop there. While you are looking for answers, you lean towards the ancient wisdom of Egyptian, Semitic, and, of course, Greek tales about the creation of the cosmos. What you discover there, is a common pattern; water is highly revered as a force of regeneration. Even the most important Greek poet, Homer, considers gods of water like Oceanus and Tethys the parents of all gods.


“For I am faring to visit the limits of the all-nurturing earth, and Oceanus, from whom the gods are sprung, and mother Tethys…”
Homer, Iliad 14.246


After all this, can you really blame Thales for thinking that water is the one and only substance out of which everything derives?


The Earth Floats on the Sea?

Portrait of Andrea Doria as Neptune, by Bronzino (Agnolo di Cosimo), ca. 1545-6, Brera Pinacoteca


Thales believed that the earth floated on water. This was a conclusion he had drawn after he observed that the earth presented a solidity and immobility that the sea did not. Compatible with this view, was also Thales’ belief that earthquakes were caused by the oceans’ roughness.


These ideas can also be traced back to Greek mythology where the ocean god Poseidon was also called “the Earth Shaker” and was considered to be the one responsible for earthquakes.


Furthermore, there is a debate as to whether Thales believed that the earth was flat or spherical. Although there are good reasons to suggest that Thales would have conceived the spherical shape of the earth through his astronomical endeavors, there is not sufficient evidence to back up this claim with certainty. Of course, it would not have been something preposterous for Thales to believe that the earth was round since this was a common understanding among ancient Greek philosophers and astronomers.


Did Thales Believe in the Concept of Soul?

Thales, engraving by Wilhelm Meyer, 1875


Thales of Miletus was a naturalist philosopher trying to explain the world by observing natural phenomena. He was a materialist thinker since he attributed everything to one element, water. Despite that, he seems to have believed in the concept of the soul too. According to Aristotle, Thales was the origin of the belief that the soul is a property of things that is to be found everywhere. This idea could have been the predecessor of Plato’s concept of the soul.


“Thales, too, to judge from what is recorded about him, seems to have held soul to be a motive force, since he said that the magnet has a soul in it because it moves the iron.”
Aristotle, On the Soul 405 a20-22

“Certain thinkers say that soul is intermingled in the whole universe, and it is perhaps for that reason that Thales came to the opinion that all things are full of gods.”
Aristotle, On the Soul 411 a7-8


If we judge from these fragments, Thales did not even come close to Plato’s idealism. Besides his idea of the soul as a moving force of matter at a first glance appears closer to the idea of energy than the holy spirit in Christian theology. Of course, there are many ways to interpret these lines and no way of knowing exactly what Thales said. In any case, it is more likely than not, that when Thales tried to make sense of reality, he found answers in a material substance, namely water, and not in god or an abstract idea.

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By Antonis ChaliakopoulosMSc Museum Studies, BA History & ArchaeologyAntonis is an archaeologist with a passion for museums and heritage and a keen interest in aesthetics and the reception of classical art. He holds an MSc in Museum Studies from the University of Glasgow and a BA in History and Archaeology from the University of Athens (NKUA) where he is currently working on his PhD.