The list of seven sages includes:
...There some, both at present and of old, who recognized that Spartanizing is much more a love of wisdom than a love of physical exercise, knowing that the ability to utter such remarks belongs to a perfectly educated man. Among these were Thales of Miletus, and Pittacus of Mytilene, and Bias of Priene, and our own Solon, and Cleobulus of Lindus, and Myson of Chenae, and the seventh of them was said to be Chilon of Sparta. They all emulated and admired and were students of Spartan education, could tell their wisdom was of this sort by the brief but memorable remarks they each uttered when they met and jointly the first fruits of their wisdom to Apollo in his shrine at Delphi, writing what is on every man's lips: Know thyself, and Nothing too much. Why do I say this? Because this was the manner of philosophy among the ancients, a kind of laconic brevity.
The section of the Protagoras in which appears this passage is "elaborately ironical", making it unclear which of its parts may be taken seriously, although Diogenes Laertius later confirms that there were indeed seven such individuals who were held in high esteem for their wisdom well before Plato's time. According to Demetrius Phalereus, it was during the archonship of Damasias (582/1 BC) that the seven first become known as "the wise men", Thales being the first so acknowledged.
Diogenes points out, however, that there was among his sources great disagreement over which figures should be counted among the seven. Perhaps the two most common substitutions were to exchange Periander or Anacharsis for Myson. On Diogenes' first list of seven, which he introduces with the words "These men are acknowledged wise," Periander appears instead of Myson; the same substitution appears in The Masque of the Seven Sages by Ausonius. Both Ephorus and Plutarch (in his Banquet of the Seven Sages) substituted Anacharsis for Myson. Diogenes Laertius further states that Dicaearchus gave ten possible names, Hippobotus suggested twelve names, and Hermippus enumerated seventeen possible sages from which different people made different selections of seven. Leslie Kurke contends that "Aesop was a popular contender for inclusion in the group"; an epigram of the 6th century AD poet Agathias (Palatine Anthology 16.332) refers to a statue of the Seven Sages, with Aesop standing before them.