Democritis, the founder of the atomistic philosophy, born in Abdera, Thrace, about 460 B. C, died in 361. He inherited a large fortune, travelled extensively in Asia, and after his return held high offices. Of the details of his life little is positively known. He was called the "laughing philosopher," in contrast to the "weeping philosopher" Heraclitus, because he taught that a philosopher must regard the follies of man with the most serene equanimity. He wrote many works on physical, moral, mathematical, musical, and technical subjects. The most complete collection of the remnants of his writings is that of Mullach (Berlin, 1843). He thus explains the theory of his philosophy: "Everything is composed of atoms or infinitely small elements, each with a definite quality, form, and movement, whose inevitable union and separation shape all different things and forms, laws and effects, and dissolve them again for new combinations. The gods themselves and the human mind originate from such atoms. There are no casualties; everything is necessary and determined by the nature of the atoms, which have certain mutual affinities, attractions, and repulsions".