He joined the Hamilton College faculty in 1984 after spending four years teaching in the department of modern languages at Saint Mary's College. O'Neal earned a bachelor's degree from Washington and Lee University; a master's in French from Middlebury College, and a Ph.D. from the University of California, Los Angeles.
O'Neal has served as chair of Hamilton's department of romance languages and literature. He is general director for Hamilton's Junior Year in France, a program of 30-45 American students who study for the month of September in the Basque country of France then for the remainder of the academic year in Paris. In France he has lectured at the Ecole Normale Superieure and the Sorbonne.
In 1989 O'Neal was the organizer of Hamilton's year-long events commemorating the bicentenary of the French Revolution, which included films, a debate, a roundtable of regional scholars, a concert and an art exhibit. He also served as chair of the program committee and organizer of the Ninth Annual Meeting of the Northeast American Society for Eighteenth Century-Studies.
O'Neal has written extensively in both English and French about 18th century French literature and thought. He has authored numerous books and articles, including The Authority of Experience: Sensationist Theory in the French Enlightenment (1996); and Seeing and Observing: Rousseau's Rhetoric of Perception (1985). He is currently writing a book entitled, "Changing Minds: Knowledge, Experience, and the Shifting Perception of Culture in Eighteenth-Century France."
He has served as president and chair of the nominating committee for the Northeast American Society for Eighteenth-Century Studies; is a member of the Modern Language Association, the American Association of Teachers of French, and the Rousseau Association; has received a national endowment for the Humanities Fellowship for College Teachers and Independent Scholars; serves on the editorial board of Philosophiques; and is a member of Phi Sigma Iota, International Foreign Language Honor Society.