Democritus, << dih MOK rih tuhs >> (460?-370? B.C.), was a Greek philosopher. He argued that the world consisted of an infinite number of atoms moving in an infinite void. These atoms are invisible and indivisible particles of matter that were ungenerated and indestructible. They differ from one another in size, shape, and position. Each thing in the world is a different combination of these atoms. Our world came about as the chance combination of atoms, and since there are an infinite number of atoms, innumerable other worlds also have come to be.
Democritus believed all sensation is a form of touch resulting from atoms colliding with the sense organs. But the senses do not provide true knowledge of reality. He reasoned that the senses reveal a world of colors, smells, and tastes while, in reality, only atoms and the void exist. True knowledge–that of the atoms and the void–comes from the intellect, not the senses.
Democritus was born in Abdera in northern Greece. He wrote on ethics, physics, mathematics, literature, and language, but only fragments of his works survive. We know of his theory of atomism through the testimony of other ancient authors.