Plato.. Plato is one of the world’s best known and most widely read and studied philosophers. He was the student of Socrates and the teacher of Aristotle, and he wrote in the middle of the fourth century B.C.E. in ancient Greece. Though influenced primarily by Socrates, to the extent that Socrates is usually the main character in many of Plato’s writings, he was also influenced by Heraclitus, Parmenides, and the Pythagoreans.
“For if you suppose that by killing human beings you will prevent somebody from reproaching you for not living correctly, you do not think nobly.” - Socrates to the men condemning him to death, Plato, Apology of Socrates, 39d.