The ancient Greek thinkers dedicated to seeking truth through reason were called philosophers (philosophos = philo "love" + sophia "wisdom").
| Philosopher | Era | School/Focus | Key Idea |
|---|---|---|---|
| Thales | 6th c. BCE | Milesian | Water as arche (first principle) |
| Heraclitus | 6th c. BCE | Ephesian | Flux ("no man steps in same river") |
| Parmenides | 5th c. BCE | Eleatic | Being is; non-being not |
| Socrates | 470–399 BCE | Athenian | Elenchus; "unexamined life not worth living" |
| Plato | 427–347 BCE | Academy | Forms; Philosopher-King |
| Aristotle | 384–322 BCE | Lyceum | Logic, categories, virtue ethics, empiricism |
| Epicurus | 341–270 BCE | Garden | Ataraxia via simple pleasures, friendship |
| Zeno of Citium | 334–262 BCE | Stoa | Virtue = sole good; live per nature |
| Pyrrho | 360–270 BCE | Skepticism | Suspend judgment (epoché) |
Greek philosophy founded Western intellectual tradition: science, law, theology, political theory, university. The word philosophy itself preserves their mission: love of wisdom.