Prof. Mattison completed his doctoral studies at the University of Notre Dame. During these years he studied Thomistic moral theology under Dr. Jean Porter, and spent a year on a Fulbright Fellowship in Fribourg, Switzerland doing dissertation research under the guidance of Fr. Servais Pinckaers, O.P. He then spent two years as a Visiting Assistant professor at Notre Dame, and another two at Mount St. Mary's University in Emmitsburg, MD before joining the faculty at the Catholic University of America’s School of Theology & Religious Studies. Prof. Mattison spent ten years at The Catholic University of America. After tenure he served as Associate Dean for Undergraduate Studies, and one year as Interim Dean of the School of Theology and Religious Studies. He also began to write and speak on Catholic higher education. He returned to Notre Dame in 2016 with a joint appointment as Wilsey Family Associate Professor in the Department of Theology as well as Senior Advisor for Theological Formation in the Alliance for Catholic Education, where he helps prepare Catholic school teachers. Besides having served in leadership roles in the Ethics and Catholic Theology Group and Moral Theology Groups at the Society of Christian Ethics and Catholic Theological Society of America, respectively, Prof. Mattison co-founded and served as Executive Director of the annual New Wine, New Wineskins symposium for pre-tenure Catholic moral theologians.