History of the Greek alphabet Plutarch criticizes Herodotus for prejudice and misrepresentation. Furthermore, he argues that "Gephyraei" were Euboeans or Eretrians and he doubts the reliability of Herodotus' sources. Plutarch and other ancient Greek writers credited the legendary Palamedes of Nauplion on Euboea with the invention of the supplementary letters not found in the original Phoenician alphabet. The distinction between "Eta" and "Epsilon" and between "Omega" and "Omicron", adopted in the Ionian standard, was traditionally attributed to Simonides of Ceos (556-469). Plutarch goes further back to describe an older Greek writing system, similar as he attested to the Egyptian writing. In his “Discourse Concerning Socrates’s
San (letter) San (letter) San (Ϻ) was an archaic letter of the Greek alphabet. Its shape was similar to modern M, or ϡ, or to a modern Greek Sigma (Σ) turned sideways, and it was used as an alternative to Sigma to denote the sound . Unlike Sigma, whose position in the alphabet is between Rho and Tau, San appeared between Pi and Qoppa in alphabetic order. In addition to denoting this separate archaic character, the name "San" was also used as an alternative name to denote the standard letter Sigma. The existence of the two competing letters Sigma and San is