Idea

Ideas

20 concepts

Central concept

Virtue

Aretē is often translated as virtue, but it means something closer to excellence or being fully what you are. A knife has aretē when it cuts well. A person has aretē when they reason well, act justly, and live courageously. Socrates argued that virtue is knowledge. Aristotle said it is a habit. The Stoics believed it is the only thing that matters. The question of what makes a good life runs through every school of Greek thought.

Theophrastus, Socrates, Plato, Aristotle, Diogenes +2

Logos

Reason, word, principle. The rational order that runs through all things, or the capacity in us to perceive it.

Heraclitus, Zeno of Citium, Plato, Aristotle +1

Justice

Giving each what is owed. For the Greeks, justice was not just law but the harmony of the soul and the city.

Socrates, Plato, Aristotle, Protagoras

Happiness

Eudaimonia: not pleasure, but flourishing. The Greeks asked not ‘are you happy?’ but ‘are you living well?’

Aristotle, Epicurus, Democritus, Pyrrho +2

Being

What is real? What truly exists? Parmenides asked the question, and philosophy has never stopped trying to answer it.

Gorgias, Anaximander, Parmenides, Plato +3

Nature

Physis: the way things grow, move, and are. To live according to nature was the first and last commandment of Greek philosophy.

Theophrastus, Anaximander, Anaximenes, Thales +10

Skepticism

The discipline of doubt. Not cynicism, but the honest admission that certainty may be beyond us.

Gorgias, Pyrrho, Socrates, Protagoras +1

Reason

The capacity to think, argue, and understand. The Greeks believed it is what makes us most fully human.

Thales, Parmenides, Socrates, Plato +6

Change

Is change real, or an illusion? Heraclitus said everything flows. Parmenides said nothing does. The debate defined metaphysics.

Anaximander, Anaximenes, Heraclitus, Parmenides +3

Moderation

Nothing in excess. The golden mean. The Greeks distrusted extremes and prized the disciplined middle.

Aristotle, Epicurus

Stoic Ethics

Virtue is the only good. Everything else (health, wealth, reputation) is indifferent. You control your judgments, nothing more.

Zeno of Citium, Chrysippus

Natural Law

A law above all human laws, written into the structure of the cosmos itself. The Stoics said reason is that law.

Zeno of Citium

The Republic

Not a word for a building, but for an idea: the common good, the public thing, a government that belongs to its people.

Plato

Atoms & the Void

The universe is particles in empty space. Everything you see, from stars to your own thoughts, is atoms in motion.

Democritus, Epicurus, Leucippus

Pleasure

Is pleasure the highest good? The Cyrenaics said yes without qualification. Epicurus agreed, then quietly redefined pleasure until it looked more like calm than sensation.