Orvieto’s citizens had long been consumed by the full humanity of Jesus, Mary, and the doctrine of hypostatic union – that Christ was fully human and fully divine – which the Cathar heretics denied. In fact, one of the main points of the Nicene Creed was to elaborate upon the mystery of Jesus’s Incarnation: “begotten, not made, of one Being with the Father … by the power of the Holy Spirit he became incarnate from the Virgin Mary, and was made man.” Therefore, Ugolino almost obsessively promotes the genuineness of Mary’s human substance, which, in turn promotes the verity of Jesus’s full humanity.