Thrasymachus of Bithynia (fl. 427 B.C.E.) is known mainly as a character in Plato’s Republic, whom Socrates trounces in preliminary attempts to define justice. Thrasymachus asserted that justice is no more than what benefits those in power, and that it is therefore of no use to those who are ruled by them. In real life, Thrasymachus is believed to have traveled and taught throughout Greece, besides being famous in Athens. In a speech he wrote for a member of the assembly, he advocated for Greek unity and efficiency in government.
Some ancient Sophists believed the world was composed of four elements, and some considered them to be divine in nature (iStock).