-470 – -399
Socrates (c. 470–399 BCE) was an Athenian philosopher whose thought survives almost entirely through the dialogues of his student Plato. He is credited with developing the Socratic method of elenctic inquiry and redirecting Greek philosophy toward ethics and epistemology. His insistence that the unexamined life is not worth living and his trial and execution by Athens made him the paradigmatic martyr of philosophical integrity.
Developed the Socratic method (elenchus) as a systematic form of philosophical inquiry through dialogue
Shifted Greek philosophical focus from cosmology to ethics, virtue, and the nature of the soul
Articulated the doctrine that virtue is knowledge and that wrongdoing is a form of ignorance
Inspired the founding of multiple philosophical schools, most notably Platonism and Cynicism
His trial and death became a defining episode in the history of philosophy and free inquiry