I’m still reading David A. Bell’s The First Total War, and in explaining his theory of how, paradoxically, the new concept that war was an aberration that could and should be eliminated led to the modern type of “total war” ushered in by the Napoleonic Wars, Bell traces the popularity of the idea back to François Fénelon, who had been nothing but a name to me, dimly recalled from high-school French classes with the severe Mme Ruegg. In 1699, Fénelon published a novel, Les Aventures de Télémaque (The Adventures of Telemachus), that “more than anything else… saved him from the thickets of scholars’ footnotes and made him a sizable figure in European history and literature”; a sequel to the Odyssey, it “caused an immediate sensation, going through fifteen French editions in 1699 alone and at least sixty more over the course of the eighteenth century. Translated into every major language, it had particular success in English, where it appeared in at least fifty separate editions before 1800. Today, it is exasperatingly difficult to see why….” (Google Books has an 1857 American edition here, if you want to investigate for yourself.) And “in each of its eighteen long sections, Fenelon insistently put forth the claims of conscience, denounced war, and urged Christian pacifism on Christian rulers.”
Now, throughout the novel “Telemachus has by his side the drearily wise counselor Mentor, who ensures that his pupil’s slightest surrender to temptation meets with quick and loquacious correction,” and on p. 64, Bell writes “The word ‘mentor,’ which we owe to Fenelon, remains a telling sign of its appeal.” I regarded this claim skeptically, having always assumed the word was taken from Homer, but lo and behold, when I went to the OED I discovered that the entry for mentor, revised just this last June, says:
[< French mentor (1735 in sense 2 in a book title, 1749 in sense ‘guide, adviser’) < Mentor, the name of a character in F. de S. de la Mothe-Fénelon's Les Aventures de Télémaque (1699), after ancient Greek Μέντωρ, the name of a character in the Odyssey, in whose likeness Athena appears to Telemachus and acts as his guide and adviser. Compare German Mentor (1725 in sense ‘court tutor, adviser’ in a book title), Italian mentore (a1789), Spanish mentor (1785 in a book title).
N.E.D. (1906) notes that the emphasis Fénelon places on the role of Mentor as a counsellor is key to the currency of this word in English and French. Fénelon's work was one of the most popular political novels of its time, and had been translated into English by 1699-1700, German by 1700, and Italian by 1719: numerous English adaptations in prose, verse, and drama appeared in the course of the 18th cent., including a translation by Smollett.
The ancient Greek name is recorded as a historical personal name in the 4th cent. It may be cognate with MIND n.]
(The original OED etymology just said it was “a. F. mentor, appellative use of the proper name Mentor, Gr. Μέντωρ.”) You never know what you’re going to learn from a history book.