Pope Leo XIV's devotion to St. Augustine, his life and ministry as a member of the Augustinian order and his focus on the unity of the church are reflected in his episcopal motto and coat of arms.
When he appeared on the balcony of St. Peter's Basilica shortly after his election May 8, he introduced himself as "an Augustinian, a son of St. Augustine."
And he explained that the cardinals who elected him "have chosen me to be the Successor of Peter and to walk together with you as a Church, united, ever pursuing peace and justice, ever seeking to act as men and women faithful to Jesus Christ, in order to proclaim the Gospel without fear, to be missionaries."
His episcopal motto is, "In Illo uno unum," or literally "In the One, we are one."
Vatican News explained that the phrase is taken from St. Augustine's "Exposition on Psalm 127," where he explains that "although we Christians are many, in the one Christ we are one."
As a cardinal, he told Vatican News in 2023, "As can be seen from my episcopal motto, unity and communion are truly part of the charism of the Order of St. Augustine, and also of my way of acting and thinking."
"I believe it is very important to promote communion in the church, and we know well that communion, participation and mission are the three keywords of the Synod" of Bishops on synodality, he said. "So, as an Augustinian, for me promoting unity and communion is fundamental."
His shield, now topped by a miter instead of the red galero hat on the shield of cardinals, is divided diagonally into two. The upper half features a blue background with a white lily or fleur-de-lis, symbolizing the Virgin Mary, but also his French heritage.
The lower half of the shield has a light background and displays an image common to the religious orders named after and inspired by St. Augustine: a closed book with a heart pierced by an arrow.
Vatican News said, "This is a direct reference to the conversion experience of St. Augustine himself, who described his personal encounter with God's word using the phrase: 'Vulnerasti cor meum verbo tuo' -- 'You have pierced my heart with your Word.'"
