 He retired from teaching in 1972, and in 1976 received the honorary D.Litt.from Edinburgh University.Mossner was a member of Phi Beta Kappa, The Modern Humanities Research Association, The International Association of University Professors of English, The Texas Institute of Letters, the advisory board of the Augustan Reprint Society, the South Central Modern Language Association, the Society of American Historians, and the Fortnightly Club of Austin.