Democritus (l. c. 460 - c. 370 BCE) was a Greek philosopher and younger contemporary of Socrates, born in Abdera (though other sources cite Miletus) who, with his teacher Leucippus (l. 5th century BCE), was the first to propose an atomic universe. Democritus claimed that everything is made of tiny uncuttable building blocks known as atoms.

More about: Democritus


  • c. 460 BCE - c. 370 BCE
    Life of Democritus, pupil of Leucippus; development of the concept of the atomic universe.
  • c. 445 BCE
    Leucippus of Abdera, the philosopher, is said to have conceived of the atomic universe. His pupil is Democritus.