Socrates (470 – 399 BCE) was the earliest of the great Greek philosophers whose work is still studied today. He wrote nothing himself, but two of his pupils, Plato and Xenophon, recorded both his style of teaching and his thoughts. The Socratic Method of teaching is to ask questions, requiring students to think for themselves.
Socrates questioned everything, including the government of Athens, and referred to himself, according to Plato, as a gadfly, a stinging fly that annoys livestock. The word has come to mean someone who persistently challenges people in power, the status quo, or a popular position. His activities as an uncomfortable goad to the Athenian authorities ultimately cost him his life. He was accused of impiety—for not worshipping the gods appropriately—and the corruption of youth—for infusing his students with the spirit of criticism of Athenian society. Rather than escaping from Athens Socrates chose to stand trial and drink the hemlock that was his death sentence.