structural:scholar_edition, information:filtering
Late period: priest at Delphi

Some time c. AD 95, Plutarch was made one of the two sanctuary priests for the temple of Apollo at Delphi; the site had declined considerably since the classical Greek period. Around the same time in the 90s, Delphi experienced a construction boom, financed by Greek patrons and possible imperial support. His priestly duties connected part of his literary work with the Pythian oracle at Delphia: one of his most important works is the "Why Pythia does not give oracles in verse" ("Περὶ τοῦ μὴ χρᾶν ἔμμετρα νῦν τὴν Πυθίαν"). Even more important is the dialogue "On the 'E' at Delphi" ("Περὶ τοῦ Εἶ τοῦ ἐν Δελφοῖς"), which features Ammonius, a Platonic philosopher and teacher of Plutarch, and Lambrias, Plutarch's brother.

According to Ammonius, the letter E written on the temple of Apollo in Delphi originated from the Seven Sages of Greece, whose maxims were also written on the walls of the vestibule of the temple and were not seven but actually five: Chilon, Solon, Thales, Bias, and Pittakos. The tyrants Cleobulos and Periandros used their political power to be incorporated in the list. Thus, the E, which was used to represent the number 5, constituted an acknowledgement that the Delphic maxims actually originated from only five genuine wise men.