| Term | Definition |
| Aesop | created fables that taught a moral lesson |
| Anaximander | philosopher; student of astronomy and geography; sun-dial |
| Aristarchus | Astronomer who believed that the earth and planets revolved around the sun |
| Cleisthenes | Athenian leader who was thought to be the founder of democracy |
| Aristotle | Philosopher; pupil of Plato; developed scientific method |
| Euclid | mathematician; used logic to do geometry and created basic principles of geometry |
| Herodotus | "Father of history"; explored the known world |
| Hippocrates | "Father of medicine"; developed principles of modern medicine; "Hippocratic Oath" |
| Pericles | Athenian leader who brought democracy to Athens; constructed the Parthenon |
| Plato | Philosopher and student of Sacrates; wrote a book called the Republic |
| Pythagorus | philosopher and mathematician who discovered the Pythagorean theorem |
| Socrates | philosopher; searched for ethical knowledge; taught by asking questions |