He was named a knight in the Order of the Palmes Académiques by the French Ministry of Education in 1998, and promoted to officer in 2008. O'Neal directed the Hamilton in France program six times between 1986 and 2004 and has lectured at the Sorbonne and the Ecole Normale Supérieure.
He has written extensively in both French and English about 18th-century French literature and thought. O'Neal has authored numerous books and articles, including Changing Minds: The Shifting Perception of Culture in Eighteenth-Century France (2002) and The Authority of Experience: Sensationist Theory in the French Enlightenment (1996). His latest authored book, The Progressive Poetics of Confusion in the French Enlightenment, was published by University of Delaware Press in 2011. O'Neal's most recent edited books are Approaches to Teaching Rousseau's Confessions and Reveries (Modern Language Association, 2003 with Ourida Mostefai) and The Nature of Rousseau's Rêveries: Physical, Human, Aesthetic (from the Voltaire Foundation in Oxford in 2008).