This led [the Stoics] to coin and use a word that is still crucial to our modern vocabulary: cosmopolitanism, which literally means ‘being a citizen of the world.’ Or as Socrates—arguably the most important influence on all Hellenistic schools of philosophy—put it: ‘Never reply to one who asks [your] country, ‘I am an Athenian,’ or ‘I am a Corinthian,’ but ‘I am a citizen of the universe.’