Father Cassian Derbes, O.P., is a priest of the Order of Preachers assigned to the priory of Santa Maria sopra Minerva in Rome. He is a member of the Dominican Province of Saint Joseph (Eastern, USA). He is a professor of spiritual theology at the Pontifical University of Saint Thomas Aquinas (Angelicum). He has a Doctorate in Theology (S.T.D.) from the Pontifical University of Saint Thomas Aquinas in Rome (Angelicum), a Licentiate in Theology (S.T.L.) from the Dominican House of Studies in Washington, DC, and a Bachelor’s degree (B.A.) from New York University (N.Y.U.). Father Cassian has served as a parochial vicar at Saint Patrick’s Church in Columbus, Ohio, Saint Mary’s Church in New Haven, Connecticut and Saint Vincent Ferrer Church in New York City. He is a member of the Governing Board of the Nostra Aetate Foundation of the Pontifical Council for Interreligious Dialogue at the Holy See. Father Cassian is a Missionary of Mercy, having been appointed by Pope Francis in 2015.