In which water becomes the answer to everything, and a man from Miletus asks the first question that mattered
♦ ♦ ♦Let’s see what already lives in your mind. Don’t worry about being right — just write whatever surfaces.
Any names, ideas, images, stories — from the very earliest thinkers, before Socrates and Plato...
2,600 years. That is roughly how long ago a man stood on the coast of what is now Turkey and asked a new kind of question. Every culture already had rich, powerful stories about where the world came from — creation myths, divine narratives, sacred cosmologies. Thales did not reject those stories. He simply asked a different question: not who made the world, but what is it made of? And with that, a new way of thinking was born — one that would sit alongside, and sometimes in tension with, the older ways.
Philosophy did not replace myth or faith. It opened a new door. What Thales began was the tradition of trying to understand the world through unaided human reason — and the story of that tradition, with all its triumphs and limits, is what this course is about.
In the sixth century before Christ, the most important city in the Greek world was not Athens. It was Miletus — a prosperous trading port on the western coast of Anatolia, modern Turkey. Ships arrived from Egypt, Phoenicia, and Babylon, carrying not just goods but ideas. It was in this crossroads of cultures that three men asked questions nobody had asked before.
Thales is traditionally called the first philosopher. Aristotle, writing two centuries later, described how Thales and his contemporaries approached the question of first principles:
Thales’ answer was water. Everything, he claimed, was ultimately made of water. It seems absurd at first — but think about what he was really doing. He was saying: behind the apparent chaos of the world, there is one underlying substance, and human reason alone might be able to discover it.
Thales was also said to have predicted a solar eclipse in 585 BC — the first recorded prediction of a natural event using natural reasoning. Whether the story is true or not, it tells us how the Greeks remembered him: as a man who could read the natural world through careful observation and reasoning.
Thales’ student Anaximander thought his teacher was on the right track but made one crucial objection: why water and not fire? Or earth? If you pick any one element, you have to explain why it should be privileged over the others. Anaximander’s solution was breathtaking: the fundamental substance must be something beyond any particular thing. He called it the apeiron — the boundless, the infinite, the indefinite.
Anaximander also proposed that human beings evolved from fish-like creatures that once lived in the sea — an idea strikingly close to evolutionary theory, arrived at 2,400 years before Darwin.
The third Milesian, Anaximenes, proposed air as the fundamental substance. His key insight was the mechanism: air becomes different things through condensation and rarefaction. When air thins, it becomes fire. When it thickens, it becomes wind, then cloud, then water, then earth, then stone. This was a remarkable early attempt to explain change through a physical mechanism — a single process that could account for the diversity of the material world.
These three men — Thales, Anaximander, Anaximenes — disagreed about the answer. But they agreed on something far more important: the question. They assumed that behind the apparent chaos of the world, there was a rational principle that could be discovered by human thought alone — without appeal to sacred tradition or received authority.
This was not a rejection of the sacred. Many later philosophers would find that reason and faith illuminate different aspects of the same reality. But the Milesians opened a new path — the path of rational inquiry — and it is that path we follow in this course. Where it meets, enriches, or challenges the paths of faith and tradition is one of philosophy’s most enduring stories.
Notice something, though: the Milesians asked “What is everything made of?” They did not yet ask the question that would come to matter even more: “How should we live?” Both questions run through the entire history of philosophy. This course follows them both — and watches for where they converge.
The Milesian philosophers were wrong about water and air and the apeiron. But they were right about something much more important. Let’s break down their contribution into three ideas that still shape how we think today.
The world can be investigated through natural causes using reason.
Alongside the rich mythological tradition that explained the world through divine action, the Milesians proposed something new: that we could also look for material causes by observing nature and reasoning about it. Thunder might be explained as a clash of clouds, not only as Zeus’s anger.
This approach — seeking natural explanations through observation and reasoning — would eventually develop into what we now call natural philosophy and, later, science. It did not claim to have all the answers. But it opened a powerful new line of inquiry.
Behind the many, there is the one.
The world appears to contain millions of different things: rocks, rivers, stars, people, trees. The Milesians said: no. Underneath all this diversity, there is one fundamental thing. Finding that one thing is the task of philosophy (and later, of physics).
Modern physics still pursues this dream. The quest for a “Theory of Everything” — a single equation that explains all forces and particles — is a direct descendant of Thales asking “what is everything made of?”
Questions can be settled by the quality of the argument.
Notice that Anaximander disagreed with Thales — his own teacher. And Anaximenes disagreed with both. What made this remarkable was the grounds for disagreement: not rival authorities, not competing revelations, but better reasoning. Anaximander did not say “a different tradition told me so.” He said “here is a stronger argument.”
This tradition of open, rational dialogue — where the argument matters more than who said it — is one of philosophy’s most enduring contributions. It does not claim to be the only way of knowing. But it insists that reason deserves a seat at the table.
The Milesians assumed that the world was fundamentally one thing that underwent change. But this raises a devastating problem that the next generation of philosophers would wrestle with:
Think about it before clicking: If everything is really one substance, how does change happen? How does water become fire? How does the one become the many?
This is the Problem of Change — and it will dominate the next three lessons. Heraclitus will say everything is constantly changing. Parmenides will say change is an illusion. Democritus will say everything is made of tiny unchanging atoms moving in empty space. The argument is still not settled.
Each lesson gives you 3 dates to lock into memory using your PAO system. Split each year into two-digit pairs, look up Person–Action–Object from your personal table, then fuse them into a single vivid image.
The traditional date of the birth of philosophy. Encode “05” and “85” from your PAO. Link to the sun going dark over a battlefield as two armies stop fighting in terror.
The man who proposed the infinite. Encode “06” and “10” from your PAO. Link to a vast, formless, swirling void — the apeiron — from which worlds are born.
The first philosopher. Encode “06” and “24” from your PAO. Link to a man standing at the edge of the sea, looking at water and seeing the secret of everything.
Cover the dates above. Can you recall all three?
1. When did Thales predict the eclipse?
2. When was Anaximander born?
3. When was Thales born?
Over this course you will place the key thinkers, ideas, and dates of Western philosophy into 50 locations in a memory palace of your own choosing. By Lesson 50, you will have a complete chronological journey stretching from the Pre-Socratics to the present day — stored in places you already know.
What you need: A building, a route, a neighbourhood, a journey — any sequence of real places you know well enough to walk through in your mind. It could be your childhood home, a familiar walk, your school, a hotel you stayed in, a city you love. The only requirements: you need at least 50 distinct spots, and you must be able to walk through them in a consistent order.
Some people use a single large building. Others string together several familiar places. There is no wrong answer — only your answer.
Your first location holds The Birth of Wonder — Thales and the Milesian School. You are going to place five vivid images here. When you think of this location from now on, these images should be impossible to miss — bizarre, oversized, sensory, unforgettable.
1. A man cupping seawater in his hands, staring into it with absolute wonder — Thales seeing the secret of everything in water. His face is lit by the reflection.
2. The sun going black — a solar eclipse darkening the courtyard, soldiers dropping their swords in terror. 585 BC. Your PAO for 05-85.
3. A swirling, formless void pouring out of a cracked amphora — Anaximander’s apeiron, the infinite, spilling out endlessly. Neither water nor fire nor earth — something before all of them.
4. A bellows blowing air that thickens into stone — Anaximenes’ mechanism of condensation and rarefaction. Air becoming wind becoming cloud becoming water becoming earth.
5. Three men arguing passionately — Thales, Anaximander, and Anaximenes, each pointing at a different element, disagreeing but using reasons. This is the birth of rational inquiry itself.
Describe exactly where you place each image in your chosen location. Be specific — on the doorframe, floating above the table, blocking the path. The more bizarre, oversized, and sensory, the stronger the memory.
Choose 2–3 of these questions to reflect on.
Thales said everything is water. What might have led him to this answer? And does the answer even matter — or was the question itself the breakthrough?
Anaximander publicly disagreed with his own teacher, Thales. In many ancient cultures, this would be unthinkable. What does it tell us about Greek intellectual culture that a student could say “my teacher is wrong”?
Before the Milesians, people explained the world through myths. After them, through reason. But has myth really disappeared? Where do we still use mythological thinking today?
Modern physicists are still looking for a single theory that explains everything. Is this the same quest Thales began? Or is the modern version fundamentally different?
Anaximander said humans came from fish-like creatures. He arrived at this 2,400 years before Darwin. How did he get there through pure reasoning?
Philosophy began not in Athens but in Miletus — a trading port where many cultures met. Is this a coincidence? Does philosophy need a crossroads?
The Milesians asked “what is everything made of?” but not “how should we live?” Which question matters more? Can you answer one without answering the other?
Start the timer, then write everything you can remember from this lesson — without looking back.
Don’t look back. Retrieve from memory.
585 BC — Thales predicts a solar eclipse (birth of philosophy)
c. 610 BC — Birth of Anaximander (the apeiron)
c. 624 BC — Birth of Thales (the first philosopher)
Name each philosopher and what they proposed as the fundamental substance:
Thales (c. 624–546 BC) — Everything is water
Anaximander (c. 610–546 BC) — The fundamental principle is the apeiron (the boundless/infinite)
Anaximenes (c. 586–526 BC) — Everything is air (via condensation and rarefaction)
What were the three revolutionary ideas the Milesians introduced?
Naturalism — The world can be investigated through natural causes using reason
Monism — Behind the many, there is one fundamental substance
Rational Inquiry — Questions can be settled by the quality of the argument
Walk through Location 1. List the 5 images and where you placed them:
What helped you remember best in this lesson — the story, the ideas, the PAO images, or the memory palace? Why?
In Lesson 2, we meet a man who said you cannot step into the same river twice. Heraclitus of Ephesus saw the world as an eternal fire — everything flows, nothing stays the same. He was brilliant, obscure, and possibly mad. And he was the first philosopher to hint that the answer to “how should we live?” might be hidden inside the answer to “what is everything made of?”
This lesson’s content returns in: Lesson 4 (+3), Lesson 8 (+7), and Lesson 15 (+14).
This is a 50-lesson journey through 2,600 years of philosophy. It follows the timeline honestly. But it is also a story with a shape — a question that deepens as we go. The Milesians asked “what is everything made of?” Later philosophers will ask “how should we live?” And the deepest question of all — whether anything can free a person from guilt, from fear, from the weight of being human — will emerge slowly and find its answer in an unexpected place. Pay attention to what each philosopher leaves unresolved. The gaps matter as much as the answers.