The Epistle of Mathetes to Diognetus (Πρὸς Διόγνητον Ἐπιστολή) is an example of Christian apologetics, writings defending Christianity against the charges of its critics. The Greek writer and recipient are not otherwise known. Estimates of dating based on the language and other textual evidence have ranged from AD 130 (which would make it one of the earliest examples of apologetic literature), to the general era of Melito of Sardis, Athenagoras of Athens, and Tatian. The text itself does not identify the author. The word "mathetes" is the Greek word for "student" or "disciple," and it appears only once in the text, when the author calls himself a "student of the Apostles" (ἀποστόλων γενομένος μαθητής). Hence it is not a proper name at all, and its use in the title is strictly conventional. The writer, whoever he was, sounds to many like a Johannine Christian, inasmuch as he uses the word "Logos" as a substitute for "Christ" or "Jesus." Scholars have suggested individuals who could be the addressee of the Letter to Diognetus, one implausible (one of the emperor Marcus Aurelius' tutors), the other quite possible (an Alexandrian procurator, Tiberios Claudios Diognetos, c.200). Charles E. Hill cites an inscription from Smyrna, probably from the second century, by ‘Diognetos, son of Apollonius, son of Diognetos, archon’. This is evidence of an aristocratic family in Smyrna during the time of Polycarp, of which at least two members bore the name Diognetos. At least one of these two was a member of the city council, a status that would make the term κράτιστος, used of the addressee of the Letter to Diognetus, very appropriate. It is entirely possible, without verification of the author, that we have a fictitious character, since the name "Diognetus," means "God-born" in Greek. The epistle survived only in one manuscript. It was initially discovered in a 13th-century codex that included writings ascribed to Justin Martyr. The 13th-century manuscript was mostly intact, exhibiting damage only in one place, several lines in the middle of the text.