The Greek tribes quickly noticed that they did not speak the same tongue as their neighbors, and used the term "βάρβαρος" ("barbarian") for them, with the meanings "uncultured", "uncivilized" or "speaker of a foreign language". The term βάρβαρος is thought to be onomatopoeic in origin: "bar-bar"i.e. stammeringmay have been how the speech of foreign peoples sounded to Greek speakers.[42] This was also the case for the Egyptians, who, according to Herodotus, "named barbarians all those who spoke a different tongue",[43] and in later years for the Slavs, who gave the Germans the name nemec, which means "mute", while calling themselves slověnski or "people of the word".[44] In his play The Birds, Aristophanes calls the illiterate supervisor a "barbarian" who nevertheless taught the birds how to talk.[45] The term eventually picked up a derogatory use and was extended to indicate the entire lifestyle of foreigners, and finally coming to mean "illiterate" or "uncivilized" in general. Thus "an illiterate man is also a barbarian".[46] According to Dionysius of Halicarnassus, a Hellene differed from a barbarian in four ways: refined language, education, religion, and the rule of law.[47] Greek education became identified with noble upbringing. Paul of Tarsus considered it his obligation to preach the Gospel to all men, "Hellenes and barbarians, both wise and foolish".[48]
Discrimination between Hellenes and barbarians lasted until the 4th century BC. Euripides thought it plausible that Hellenes should rule over barbarians, because the first were destined for freedom and the other for slavery.[49] Aristotle came to the conclusion that "the nature of a barbarian and a slave is one and the same".[50] Racial differentiation faded away through the teachings of Stoics[citation needed], who distinguished between nature and convention and taught that all men have equal claim before the gods and thus by nature cannot be unequal to each other. With time and at least in some cases, Hellene, to use the words of Isocrates, became a trait of intellect, not race.