Democritus, one of the most remarkable of the philosophers of antiquity, was born at Abdera, a maritime city of Thrace, 460 B. C. He travelled over the greatest part of Europe, Asia and Africa, in quest of knowledge. Though his father was so rich as to entertain Xerxes and his whole army, while marching against Greece, and left his son a large fortune, yet the latter returned from his travels in a state of poverty. It was a law of the country, that a man should be deprived of the honor of a funeral, who had reduced himself to indigence. Democritus was of course exposed to this ignominy; but having read before his countrymen his chief work, it was received with the greatest applause, and he was presented with five hundred talents,—a sum nearly equal to half a million of dollars. Statues were also erected to his honor; and a decree was passed that the expenses of his funeral should be paid from the public treasury.

These circumstances display alike the great eminence of the philosopher, and an appreciation of genius and learning on the part of the people, beyond what could now be found in the most civilized communities of the world. Where is the popular assembly of the present day, that would bestow such a reward, on such an occasion?

After his return from his travels, Democritus retired to a garden near the city, where he dedicated his time to study and solitude; and, according to some authors, put out his eyes, to apply himself more closely to philosophical inquiries. This, however, is unworthy of credit. He was accused of insanity, and Hippocrates, a celebrated physician, was ordered to inquire into the nature of his disorder. After a conference with the philosopher, he declared that not the latter, but his enemies were insane. Democritus was so accustomed to laugh at the follies and vanities of mankind, who distract themselves with care, and are at once the prey to hope and anxiety, that he acquired the title of the "laughing philosopher," in contrast to Heraclitus,[12] who has been called the "weeping philosopher." He told Darius, the king, who was inconsolable for the loss of his wife, that he would raise her from the dead if he could find three persons who had gone through life without adversity, and whose names he might engrave on the queen's monument. The king's inquiries after such, proved unavailing, and the philosopher discovered the means of soothing the sorrows of the sovereign.

He was a disbeliever in the existence of ghosts; and some youths, to try his fortitude, dressed themselves in hideous and deformed habits, and approached his cave in the dead of night, expecting to excite his terror and astonishment. The philosopher received them unmoved, and, without hardly deigning to bestow upon them a look, desired them to cease making themselves such objects of ridicule and folly. He died in the one hundred and fourth year of his age, B. C. 357.

All the works of Democritus, which were numerous, are lost. He was the first to teach that the milky way was occasioned by a confused light from a multitude of stars. He may be considered as the parent of experimental philosophy; in the prosecution of which he was so ardent, that he declared he would prefer the discovery of one of the causes of the works of nature, to the diadem of Persia. He is said to have made artificial emeralds by chemical means, and to have tinged them with various colors; he likewise found the art of dissolving stones and softening ivory.

He was the author of the atomic theory; he viewed all matter, in which he included mind, as reducible to atoms; he considered the universe to consist only of matter and empty space. The mind he regarded as round atoms of fire. He argued that nothing could arise out of nothing; and also that nothing could utterly perish and become nothing. Hence he inferred the eternity of the universe, and dispensed with the existence of a Creator.

He explained the difference in substances by a difference in their component atoms; and all material phenomena, by different motions, backward or forward, taking place of necessity. He did not seem to perceive that under this word, necessity, he concealed a deity. He explained sensation by supposing sensible images to issue from bodies. In moral philosophy, he only taught that a cheerful state of mind was the greatest attainable good.

The theories of Democritus appear absurd enough in our time; but philosophy was then in its infancy. His struggles after light and truth display the darkness of the age, and the ingenuity of the philosopher. They may also teach us by what a process of mental toil, for centuries piled upon centuries, the knowledge we possess has been attained. The school he established, was supplanted, about a century after, by that of Epicurus.