Here’s a puzzle. The mosaic in this photo is in Rome’s Santa Costanza, a lovely fourth-century church with some of the oldest surviving Christian art. The mosaic is famous among scholars of Christian iconography, even among scholars of Christian jurisprudence. It depicts Christ–blond, beardless, looking like the god Apollo–giving a scroll to St. Peter. Christ is dressed in a golden toga. Scholars believe the image is meant to represent Christ giving the Law to the Church.
According to French scholar Rémi Brague, during the patristic period, “Christianity came to think of itself as a law brought by Christ in the same way that Judaism is a law brought by Moses.” This understanding, he says,
received artistic representation in images such as that of a lawgiver Christ giving St. Peter the scroll of the Law in a mosaic in the church of Santa Costanza in Rome, on the sarcophagus of Probus in Rome, or in the basilica of St. Ambrose in Milan.This scene is adapted from the pagan model of the investiture of a high functionary by the emperor. After Constantine, the ideology of the Christian empire utilized the notion of a unique law. This iconographic theme is present from the fourth century to the sixth, when it was replaced by another image in which Christ gives Peter not the Law but rather the Keys to the Kingdom.
If this reading is correct, the mosaic is an important object, not only in the history of Western art, but Western law as well. A key piece of evidence that supports the reading is the inscription on the scroll Christ holds. According to most scholars, the inscription is “DOMINUS LEGEM DAT,” or, “The Lord Gives Law.” If that’s what the scroll says, it does indeed confirm the reading of scholars like Brague.
Except that isn’t what the scroll says. As the photo, which I took this summer, shows, the scroll reads, “DOMINUS PACEM DAT,” or “The Lord Gives Peace.” Not “Law,” “Peace.” Now, I suppose, the inscription may be elliptical: Christ gives Law, the Law of Christ gives Peace, so Christ gives Peace. But that’s a strain. Besides, in Christian teaching, the Law of Christ is usually described as Love, not Peace. Does the scroll refer to Christ’s words at the Last Supper, “My peace I give to you”? Maybe. But that would definitely change the meaning of the image.
So, what’s the explanation? Perhaps, as Brague suggests, this was a conventional image in late antiquity, so the mosaic must be about law. One scholar I’ve read thinks the word “PACEM” on the scroll is an simply an incorrect reconstruction of the original “LEGEM.” Sounds plausible. But when did the reconstruction take place? The Middle Ages? Why are scholars so confident that the image is about law, when the words on the scroll are about peace? Anybody know?