a Greek rhetorician, who wrote a work against rhetoric, which Quintilian (2.17.15) calls " Rhetorices accusatio." Rhunken (Hist. Crit. Orat. Graec. p. xc.) and after him most modern scholars have considered this Agnon to be the same man as Agnonides, the contemporary of Phocion, as the latter is in some MSS. of Corn. Nepos (Phoc. 3) called Agnon. But the manner in which Agnon is mentioned by Quintilian, shews that he is a rhetorician, who lived at a much later period. Whether however he is the same as the academic philosopher mentioned by Athenaeus (xiii. p. 602), cannot be decided.
[L.S]A Dictionary of Greek and Roman biography and mythology
Smith, William
A Dictionary of Greek and Roman biography and mythology. William Smith, LLD, ed. 1890