Socrates (469-399 BC) was a classical Greek Athenian philosopher. Credited as one of the founders of Western philosophy, he is known chiefly through the accounts of later classical writers, especially the writings of his students Plato and Xenophon, and the plays of his contemporary Aristophanes. Socrates is renowned for his contribution to the field of ethics and the concept of Socratic method (a form of inquiry and debate between individuals with opposing viewpoints based on asking and answering questions to stimulate critical thinking and to illuminate ideas, dialectical). Socrates made important and lasting contributions to the fields of epistemology and logic. In 399 BC Socrates was tried on the basis of two notoriously ambiguous charges: corrupting the youth and impiety. He was accused of "failing to acknowledge the gods that the city acknowledges" and "introducing new deities." Socrates was declared guilty and sentenced to death by drinking a mixture containing poison hemlock.