Anaxagoras (500?–428 B.C.), a Greek philosopher and scientist. He introduced philosophy to Athens.
Anaximenes of Miletus a Greek philosopher of the late sixth century B.C. He belonged to the Milesian school, which was founded by Thales and continued by Anaximander.
Aristoxenus, (fourth century B.C.), a Greek philosopher and writer on musical theory.
Democritus (460?–370 B.C.), a Greek philosopher. He was a Materialist, believing that the universe can be explained in terms of matter, and an Atomist, believing that all matter is composed of tiny, indestructible particles called atoms.Democritus believed that spiritual, as well as physical, things are composed of atoms.
Diogenes (412?–323 B.C.), a Greek philosopher. A follower of the Cynic school of philosophy, Diogenes scorned pretense and unessential possessions.
Empedocles (490?–430? B.C.), a Greek philosopher, scientist, physician, and poet.
Epictetus (about 50–130 A.D.), a Greek Stoic philosopher. Like other Stoics, he resembled the Christians in his love of good and hatred of evil.
Epicurus (341–270 B.C.), the Greek philosopher who founded the Epicurean school of philosophy.
Epimenides a Cretan philosopher, poet, and prophet of the seventh century B.C. According to Pliny, he fell asleep in a cave when a youth.
Heraclides (or Heracleides) Ponticus, (fourth century B.C.), a Greek philosopher.
Parmenides a Greek philosopher of the fifth century B.C. Parmenides tried to prove by logic that change does not exist.
Plato, original name Aristocles, (427?–347 B.C. ), the Greek philosopher who built the foundations for later philosophy.
Posidoniusor Poseidonius(135?––51? B.C.), a Greek Stoic philosopher. He was the greatest scholar of his time and wrote in many fields, but his works (which have been lost) were apparently given to the uncritical gathering of facts and ideas rather than to original thought.
Protagoras of Abdera (in Thrace), a Greek philosopher of the fifth century B.C.
Socrates, (469?–399 B.C.), a Greek philosopher. Socrates believed in virtue—that there was a right way for men to act.