"Nothing exists except atoms and empty space; everything else is opinion."

Democritus

Democritus is an ancient Greek philosopher who was born in Abdera (Thrace, Greece). He is best known for his atomic theory.

When he was a young man Democritus visited Anaxagoras in Athens. He complained to him about how little he was known there. Democritus traveled a lot throughout his life. He traveled to Egypt, Persia, and Babylon, and some claim he also traveled to India and Ethiopia.

Democritus was known as the “laughing philosopher” because of the importance he placed on “cheerfulness”. He was the first philosopher to posit that what we refer to as the ‘Milky Way’ was the light of stars reaching our perception and that the universe may, in fact, be a multiverse with other planets sustaining life (a theory which physicists today are increasingly recognizing as mathematically probable).

What is Democritus known for?

Democritus’ argued that the world is made of very small particles which he called “atomos” – atom (“uncuttable” in Greek) and that these atoms make up everything we see and are.

Democritus was also a supporter of the spherical Earth hypothesis. He believed that in the original chaos from which the universe sprang, the universe was composed of nothing but tiny atoms that came together to form larger units (a theory which bears a striking resemblance to The Big Bang Theory and Nebular Theory). He also believed in the existence of many worlds, which were either in state of growth or decay (a theory which bears a striking resemblance to multiverse theory).

Democritus and the atomic theory

Democritus’ greatest contribution to modern science was arguably the atomic theory. According to Democritus’ atomic theory, the universe and all matter obey the following principles:

  • Everything is composed of “atoms”, which are physically, but not geometrically, indivisible
  • Between atoms, there lies empty space
  • Atoms are indestructible
  • Atoms have always been, and always will be, in motion
  • There is an infinite number of atoms, and kinds of atoms, which differ in shape, and size.

Democritus was not the first to propose an atomic theory, however, he is credited with illustrating and popularizing the concept, and for his descriptions of atoms which survived classical antiquity to influence later philosophers. While Democritus’ atomic theory bears little resemblance to modern atomic theory, it is more closely aligned with that of modern science than any other theory of antiquity.

Democritus is usually seen as one of the ancient Greek philosophers, however, many scholars argue that Democritus should be classified as a scientist, at least when compared to his contemporaries.