Born: 460 B.C.
Died: 370 B.C.
Democritus was a native of Abdera in Thrace and was flourished about 420 B.C. He is known for his atomic theory but he was also an excellent geometer. We know next to nothing about his life but we know that Leucippus was his teacher.
Democritus is said to have traveled widely from Ethiopia and Egypt to Persia and India in search of knowledge. He certainly visited Athens, but no one there took notice of him. (He said, according to Diogenes Laertius writing in the second century AD “I came to Athens and no one knew me”.) Democritus visited Athens principally to visit Anaxagoras, then an old man, had refused to see him.
Democritus was a contemporary of Socrates and the Sophists. Plato, his contemporary, never mentioned Democritus, but Aristotle and Hippocrates quoted him frequently. Not only this, for a long time his philosophy was ignored in Athens. Democritus worked out his theories in considerable detail. Each atom, he said, was impenetrable and indivisible because it contained no void. When you use a knife to cut an apple, the knife has to find places where it can penetrate; if the apple contained no void, it would be infinitely hard and therefore physically indivisible.
Democritus was a thoroughgoing materialist; for him, the soul was composed of atoms, and thought was physical process. There was no purpose in the universe; there were only atoms governed by mechanical laws. He disbelieved in popular religion, and he argued against the ‘nous’ of Anaxagoras.
In ethics, he considered cheerfulness the goal of life, and regarded moderation and culture as the best means to it. He disliked everything violent and passionate; he disapproved of sex, because, he said, it involved the overwhelming of consciousness by pleasure. He valued friendship, but thought ill of women, and did not desire children, because their education interferes with philosophy.
He contributed to epistemology, physics, mathematics, and technique. He dealt with logical and musical problems; avoided politics in his writing. Long before its appropriation by Epicurus, this doctrine produced an attitude toward human life that earned Democritus a reputation as “the laughing philosopher.” Democritus is the last of the Greek philosophers to be free from a certain fault, which vitiated all later ancient and medieval thought