# The Milesians

Philosophy I · Ancient Philosophy: From the Milesians to Plato · https://tryals.app/learn/philosophy-i/the-milesians

## The First Question

Philosophy in the Greek world begins at Miletus in the sixth century BC with a question and, more importantly, with a *kind* of answer. The question was what everything is ultimately made of, the **archē**, the origin and underlying principle. The novelty was not the question but the refusal to answer it with a god.

Earlier accounts explained the world by telling stories about agents: the sea is angry, the sky was fathered by someone. The Milesians replaced agency with **impersonal principles that operate uniformly**. That move, not any of their particular answers, is what makes them the first philosophers, and it is the move every science has made since.

**Thales** said the archē is **water**. The reasoning is reconstructible: water is the only substance familiar in all three states, all living things need it, and the earth appeared to float on it. He is also credited with predicting a solar eclipse and with the claim that "all things are full of gods", which in context looks less like piety than a proposal that matter is self-moving.

**Anaximander**, his student, made the sharper move. If the archē were water, he argued, water would already have overwhelmed its opposites, so the origin must be *none* of the observable elements but the **apeiron**, the boundless or indefinite. This is the first argument in Western philosophy for something unobservable on the grounds that the observable will not do the work. He also held the earth hangs unsupported at the centre of things, held in place by symmetry alone since it has no reason to move one way rather than another, an argument of remarkable purity.

**Anaximenes** proposed **air**, and added the mechanism the others lacked: **condensation and rarefaction**. Rarefied air becomes fire; condensed it becomes wind, cloud, water, earth, stone. One substance, one quantitative process, all the apparent variety of the world. That is the first reduction of qualitative difference to quantitative change, and it is arguably a deeper contribution than either of the other two answers.

> **Common pitfall:** judging the Milesians on whether their answers were right. None was. What matters is that they made the question answerable by argument and observation rather than by authority, and that Anaximander was willing to posit something unobservable because the observable candidates failed.

## Practice questions

7 of this lesson's 11 practice questions, with answers. The full set is in the app.

### 1. What makes the Milesians the first philosophers rather than simply early scientists or theologians?

A. They were the first Greek thinkers to systematically observe and catalogue the natural world
B. They replaced explanation by divine agency with impersonal principles operating uniformly
C. They broke decisively with oral tradition by committing philosophical arguments to prose texts
D. They rejected the existence of the traditional Greek gods in favour of a strict secular atheism

**Answer:** B. They replaced explanation by divine agency with impersonal principles operating uniformly

**Why:** The break is in the form of explanation. Systematic natural observation predates them, prose writing does not define the philosophical shift, and Thales at least still spoke of gods, making them immanent in matter rather than strictly atheist. Replacing agents with uniform impersonal principles is the move every science since has repeated.

Page: https://tryals.app/practice/philosophy-i/the-milesians/what-makes-the-milesians-the-first-philosophers-rather-than-simply

### 2. Which considerations plausibly supported Thales’ choice of water as the archē?

A. It is familiar in solid, liquid and gaseous states
B. It is the lightest of the elements
C. All living things require it
D. The earth appeared to rest upon it

**Answer:** A. It is familiar in solid, liquid and gaseous states; C. All living things require it; D. The earth appeared to rest upon it

**Why:** Water’s three states, its necessity to life and the apparent floating of the earth are all reconstructible motivations. Lightness is what recommended *air* to Anaximenes, and it points the other way.

Page: https://tryals.app/practice/philosophy-i/the-milesians/which-considerations-plausibly-supported-thales-choice-of-water-as

### 3. Anaximander argued that the earth remains at the centre of things because it is held up by symmetry, having no reason to move one way rather than another.

**Answer:** True

**Why:** True, and it is remarkably pure reasoning. With nothing distinguishing any direction, there is no reason for motion, so the earth stays put. No water beneath it, no pillars, no god holding it: an argument from indifference alone.

Page: https://tryals.app/practice/philosophy-i/the-milesians/anaximander-argued-that-the-earth-remains-at-the-centre-of-things

### 4. Arrange the Milesian thinkers in chronological order and note how each responds to the one before.

**Answer:**

1. Thales proposes water as the archē
2. Anaximander objects that no observable element could be the origin
3. Anaximander proposes the boundless instead
4. Anaximenes returns to an observable element but adds a mechanism

**Why:** The three form an argument rather than a list: Thales proposes, Anaximander objects and abstracts, Anaximenes returns to the observable but supplies the mechanism his predecessors lacked. Philosophy begins as a conversation.

Page: https://tryals.app/practice/philosophy-i/the-milesians/arrange-the-milesian-thinkers-in-chronological-order-and-note-how

### 5. Sort each explanatory move by whether it is characteristic of mythological or Milesian explanation.

**Answer:**

- Mythological explanation: The sea storms because a god is angry, The world came about through the acts of divine agents
- Milesian explanation: All substances arise from one material by a uniform process, The origin must be unobservable because no observable will do, The earth stays put because nothing distinguishes any direction

**Why:** The dividing line is agency. Myth explains by what someone wanted; the Milesians explain by what always happens. Every explanation on the right could in principle be argued about, which is the point.

Page: https://tryals.app/practice/philosophy-i/the-milesians/sort-each-explanatory-move-by-whether-it-is-characteristic-of

### 6. Thales famously asserted that 'all things are full of gods'. Given the overarching Milesian shift away from mythological narrative, what does this claim signify for early cosmology?

A. It presents an early theological defence of traditional Olympian piety
B. It conceives of matter as possessing its own internal power of movement
C. It treats physical substances as direct extensions of conscious divine will
D. It denies the reality of the physical world in favour of spiritual forces

**Answer:** B. It conceives of matter as possessing its own internal power of movement

**Why:** Reading Thales as devout misinterprets his vocabulary; the Milesians stripped away divine whimsy to explain natural change from within physical reality itself, foreshadowing dynamic material principles rather than establishing pantheistic worship.

Page: https://tryals.app/practice/philosophy-i/the-milesians/thales-famously-asserted-that-all-things-are-full-of-gods-given

### 7. Complete the account of Anaximander’s argument for the apeiron.

**Answer:** If the origin of everything were one of the observable elements, that element would long since have **overwhelmed** its opposites. The origin must therefore be **none** of them, and Anaximander calls it the **apeiron**. This is the first argument in Western philosophy for something **unobservable** on the grounds that the observable candidates fail.

**Why:** The argument is genuinely powerful: an unlimited quantity of one element would have swamped the rest long ago, so the origin must be indefinite. Positing an unobservable because the observables fail is a move science has repeated ever since.

Page: https://tryals.app/practice/philosophy-i/the-milesians/complete-the-account-of-anaximanders-argument-for-the-apeiron