Ezra Sullivan, O.P., a native of California, is a Dominican friar of the Province of St. Joseph in the United States. Having served in a parish after ordination to the priesthood, he is now professor of moral theology and psychology at the University of St. Thomas Aquinas in Rome (Angelicum). He is the author of Habits and Holiness: Ethics, Theology, and Biopsychology (Catholic University of America Press, 2021).