This introduces the era of the philosophers--a remarkable class of men, who grew up in the mercurial atmosphere of Greece. One of the most distinguished of them was Democritus, born 460 B.C. He came of noble descent, and belonged to so wealthy a family of Abdera that his father was able to entertain Xerxes on his return to Asia. The King left some Chaldean Magi to instruct his son, who, early in life, evinced a great desire for the acquisition of knowledge, and after studying under Leucippus, travelled to Egypt, Persia, and Babylon. He almost seemed a compound of two different characters, uniting the intellectual energy of the sage with the social feelings of a man of the world. Living in ease and opulence, he was not inclined to be censorious or morose; having mingled much in society, he was not very emotional or sympathetic; not tempted to think life a melancholy scene of suffering, but callous enough to find amusement in the ills he could not prevent. He regarded man, generally, as a curious study, as remarkable for not exercising the intellect with which he was endowed--not so much from censurable causes as from some obliquity in mental vision. Not that he regarded him as unaccountable--a fool in the ordinary acceptation of the word, is always a responsible being, and not synonymous with an idiot. The humour of this laughing sage, grounded upon deep philosophy, was so little understood in his day that none were able to join in his merriment, nor did he expect that they should be; if he was humorous to himself, he was not so, and did not aim at being so, to others. On the contrary, he was thought to be mad, and Hippocrates was directed to inquire into his disorder, but the learned physician returned answer that not he, but his opponents were deranged. Whether this story be a fabrication or not, we may regard it as a testimony that wise men saw much truth in his philosophy. Montaigne, in his Essay on Democritus and Heraclitus, gives his preference to the former, "Because," he observes, "men are more to be laughed at than hated," showing that he regarded him as imputing folly to men rather than vice.