Thinkers

Democritus

Ancient Greek · Europe · 460 to 370 BCE

Greek thinker who held that everything is made of tiny parts that cannot be divided, moving in empty space.

What it is

Democritus was a Greek philosopher from Abdera, born around 460 BCE, who built the first full system of atomism together with his teacher Leucippus. He held that everything is made of tiny, indivisible bodies moving through an infinite void, and that the order of the world needs no purpose or design behind it.

In antiquity he was called the laughing philosopher, because he valued cheerfulness. Very little of what he wrote survives, so his views are known mostly from quotations and from the criticism of later thinkers such as Aristotle.

The main ideas

• Atoms and void. Reality consists of atoms, which cannot be divided, and empty space in which they move. Things form when atoms combine and pass away when they come apart.
• No purpose behind the order. The regular order of the world comes from the movement of atoms and does not need an aim or an intelligence directing it.
• Qualities are by convention. Colour, taste and the like are not in the atoms themselves. In his words, by convention sweet and by convention bitter, but in reality atoms and void.
• Cheerfulness as the aim. His ethics valued a cheerful, even-tempered state of mind as the aim of life.

What it looks like in practice

Picture someone looking at a loaf of bread and asking what it is really made of, and then at the taste of it, and asking where the taste is. Democritus would say the bread is atoms in the void, and that its sweetness is how those atoms meet our bodies. This is an illustration of the idea, not a saying of Democritus.

Books and moments

• His works survive only in fragments and quotations by later writers.
• The laughing philosopher is the nickname by which he was long known, set against Heraclitus, the weeping philosopher.

Questions and criticism

• Is there room for purpose? If everything is atoms and void, it is fair to ask where mind, choice and purpose fit.
• Can the senses tell us what is real? If taste and colour are by convention, the senses seem to give no direct knowledge of the atoms, and it is asked how we could know them at all.
• Is cheerfulness enough of an ethics? His ethics is sketched in fragments, and how much it amounts to is still discussed.

Close neighbours

Aristotle was his chief critic and still treated him as a serious rival. Epicurus later took up atomism, as the page on Epicurus shows.

Written by epchē in our own words, and checked against independent sources on 9 October 2026. The sources are listed below.

Philosophies they belong to or are close to

• Epicureanism

Who they connect to

Influenced

• Epicurus · Epicurus adopted the atomic theory and added a small swerve to leave room for freedom.

Influenced by

• Leucippus · Ancient writers name him as the founder of atomism and the teacher of Democritus.
• Parmenides · The atomists built their theory partly as an answer to the Eleatic argument against change and empty space.

Reacted against by

• Aristotle · Aristotle argued against atoms and the void in his physics.

Other Ancient Greek thinkers

• Thales of Miletus · 624 to 546 BCE
• Anaximander · 610 to 546 BCE
• Anaximenes · 586 to 526 BCE
• Pythagoras · 570 to 495 BCE
• Xenophanes · 570 to 475 BCE
• Heraclitus · 535 to 475 BCE
• Parmenides · 515 to 450 BCE
• Anaxagoras · 500 to 428 BCE
• Empedocles · 494 to 434 BCE
• Zeno of Elea · 490 to 430 BCE

Sources we used

• Democritus · Stanford Encyclopedia of Philosophy, read on 9 October 2026
• Democritus · New World Encyclopedia, read on 9 October 2026
• Democritus · Wikipedia, read on 9 October 2026