Thales of Miletus

The Challenge of Origins:

Can a single substance explain everything that exists?

Thales of Miletus

❯ Explore the birth of thought

Before laboratories or telescopes existed, a man on the Ionian coast dared to ask the most difficult question of all: What is the world made of? Thales of Miletus was not just a mathematician or an astronomer; he was the first human being to replace myth with reason, inaugurating what we call science today. As the founder of the Milesian School and mentor to great scholars, this is the chronicle of his revolution.

Biography of Thales of Miletus

❯ The Trajectory

Thales consolidated a new rational way of explaining reality. Before him, the world was explained through gods and legends; after him, the universe became a rational space. He was not merely a "library philosopher" but a man of the world: a traveler, political advisor, and a restless observer of nature who lived a life of both political and scientific action.

624 B.C.

Origins in Miletus

Born in Miletus, a key city where East and West met. Although his origins are debated—between Phoenician roots or Greek noble blood—Thales became the most illustrious citizen of his era.

Apprenticeship

The Mystery of Egypt

Thales traveled to the Nile Valley, where he was fascinated by how the Egyptians measured their land. He was the one who "imported" this practical knowledge to Greece, transforming it into universal logical laws.

585 B.C.

The Eclipse of War

During a battle between the Lydians and the Medes, day turned into night. Thales had predicted this solar eclipse—an event that forced peace and proved that the heavens follow rules, not divine whims.

Living Legacy

The Milesian School

He founded the first institution of rational thought in history. There, knowledge ceased to be a sacred secret and became an open debate between master and students.

At an advanced age, overcome by heat and fatigue, he passed away while attending athletic games. And although his personal life remains shrouded in mystery—some say he had a son, while others claim he remained single—his method survived: the conviction that the universe is not a whim of the gods, but a comprehensible system.

Thales of Miletus’ Thought

❯ The Leap to Logos

He was the first thinker who dared to provide a physical explanation of the Universe without resorting to the supernatural. For him, the cosmos was not a stage of chaos dominated by the whims of the gods, but a logical order (Logos). This vision laid the foundations of what we know today as physics and astronomy.

Observation

He prioritized sensory evidence over mythological tales. If something happens, the cause lies within nature.

Unity

He sought a single underlying element (Arché) behind the multiplicity of nature. Order prevails over chaos.

Change Perspective:

"Thunder is the wrath of Zeus"

The will of the gods governs the chaos of the world.

"The world is a physical system"

Phenomena are not miracles, but processes of a nature that can be measured and understood by humanity.

Expert Note: By questioning the theogonic and Olympic traditions, Thales did not only invent science; he paved the way for the birth of rational theology: discussing "God" through reason rather than just faith.
The Search for Primordial Matter

If the world is nature and not mythology…
What material is the universe made of?

Thales observed life and concluded that the origin is:

WATER

The Arche of Thales of Miletus

❯ The Water Laboratory

Thales posited water as the arche of material monism: a single substance that, through its transformations, composes the totality of the cosmos. For him, the universe was a rational space where there is no external creator, but rather a natural principle that originates everything.

Monism and States of Matter

Water transitions between solid, liquid, and gas. Thales was the first to notice that the primary element must be capable of transforming its state—being subtle (vapor) or violent (the sea)—while essentially remaining the same.

Vital Humidity

He observed that the germ of life and the nourishment of every living being is intrinsically moist. He concluded that where there is humidity, there is life, and where there is dryness, there is death.

Cosmic Support

The Earth is a flat disk floating on an infinite ocean. By understanding it as a physical platform atop water, Thales removed the need for giants or gods holding up the world, even explaining earthquakes as mere waves in the universal sea.

Move your mouse to stir the waters
The earth floats upon the waters, like a log.
— Aristotle on Thales
Status: Equilibrium The Earth does not fall into the void; it remains stable thanks to the physical laws of water.
Substance: Arché (αρχή) Water is the origin, cause, and sustenance of everything that exists.

This vision of a cosmos ordered by a single substance led Thales to search for the invisible laws that govern all forms...

Contributions of Thales of Miletus

❯ Applied Geometry

The Milesian sage applied logic to measure the unreachable. His greatest success was understanding that geometry is a universal law that repeats itself at different scales.

THALES' THEOREM

"If a line is drawn parallel to any side of a triangle, a second triangle is obtained that is similar to the first."

How is it applied? Thales imagined a triangle formed by the height of the pyramid (H) and its shadow (S). By driving a staff (h) into the ground, which projects its own shadow (s), he created a second small, similar triangle. Thanks to this, he applied a simple proportion:
H =
h · S s
Staff (h): 2m | Shadow (s): --
Pyramid Shadow (S): --
Final Height (H): 146m

The Bridge to the Cosmos: Thales proved that you don't need to climb a mountain to know its height, nor travel to the sun to understand its behavior. If the laws of geometry work on the sands of Egypt, they also govern the heavens. From measuring stone shadows, he moved on to measuring the shadows of the firmament, thus predicting the first scientific eclipse in history.

Astronomy and Eclipses

❯ The Observatory

On <strong>May 28, 585 B.C.</strong>, a battle between Lydians and Medes made history due to a cosmic event: in the heat of combat, the Sun vanished, plunging the battlefield into a darkness that forced an immediate peace.

What the armies saw as a divine omen, science saw as an unprecedented validation: Thales of Miletus had predicted the phenomenon years in advance.

Drag to view the eclipse
Total Eclipse! Thales’ Prediction
How did he achieve it?

By using Babylonian records to identify the Saros Cycle: a pattern of 18 years and 11 days after which the Sun and Moon repeat their relative positions. By observing a similar eclipse in 603 B.C., he mathematically calculated its return for 585 B.C.


Thales did more than seek order in the laws of the cosmos; he sowed a way of thinking that would transform the world forever. For him, the same reason that governed the stars should guide human understanding—a spark that ignited his disciples and gave birth to the first great school of thought in history.

The Legacy of Thales

❯ The Seed of Thought

The true magnitude of a genius is measured by the footprint they leave behind. Thales was the architect of the Milesian School, the first home of reason in the West.

Thales of Miletus
Thales
Anaximander
Anaximander

His first disciple. He proposed the "apeiron" (the infinite).

Learn more ❯
Pythagoras
Pythagoras

He took geometry into the realm of mathematical mysticism.

Learn more ❯
Anaximenes
Anaximenes

He identified air as the vital principle of all things.

Learn more ❯

Thales of Miletus did more than measure pyramids or predict eclipses; he measured the potential of human thought. By seeking the 'why' beyond myths, he laid the foundations for Western scientific thought. His legacy reminds us that to understand the universe, one must first dare to observe it.

Quotes by Thales of Miletus

❯ Sentences and Maxims

“The most difficult thing is to know ourselves; the easiest is to speak ill of others”.

Maxim of Wisdom

“Hope is the only good common to all men; those who have lost everything still possess it”.

“Seek a single wisdom. Choose a single good thing”.

These maxims are not merely ancient words; they reflect a mind that understood that all knowledge begins with oneself. Thales taught us that wisdom is the only asset that can never be taken away.