Democritus spent the inheritance which his father left him on travels into distant countries, to satisfy his thirst for knowledge. He traveled to Asia, and was even said to have reached India and Ethiopia.
It is known that he wrote on Babylon and Meroe; he visited Egypt, and Diodorus Siculus states that he lived there for five years. He himself declared that among his contemporaries none had made greater journeys, seen more countries, and met more scholars than himself. He particularly mentions the Egyptian mathematicians, whose knowledge he praises. Theophrastus, too, spoke of him as a man who had seen many countries. During his travels, according to Diogenes Laërtius, he became acquainted with the Chaldean magi. "Ostanes", one of the magi accompanying Xerxes, was also said to have taught him.
After returning to his native land he occupied himself with natural philosophy. He traveled throughout Greece to acquire a better knowledge of its cultures. He mentions many Greek philosophers in his writings, and his wealth enabled him to purchase their writings. Leucippus, the founder of atomism, was the greatest influence upon him. He also praises Anaxagoras.