In the fifth century B.C., Democritus, with guidance from his teacher Leucippus, postulated that everything in the world consists simply of different arrangements of atoms and void.

It's certainly true that the atomists like Democritus (who was picking up from his teacher Leucippus) and later philosophers (there's a good run-down in the Stanford Encyclopedia of Philosophy ...

around 600 bc Thales said that everything is water. Anaximander said that it is the conflict of opposites, Anaximenes air, Heraclitus fire. Democritus and Leucippus claimed that it was invisible ...

What is the most fundamental nature of matter? As early as 2,500 years ago, Greek philosophers debated this question. Democritus and his mentor Leucippus advanced the model most similar to that ...

Leucippus, who is a mere name to us, and Democritus, whose work is also lost to us, supposed, according to their expounders, that atoms were indestructible and eternal, ...

Leucippus and Democritus, Greek philosophers from the 5th century B.C., were the first to propose that the entire universe was made up of particles called atoms, ...