Lateran And Aquinas
Lateran IV gives the doctrinal word. Aquinas gives the machinery.
The council uses transsubstantiatis, saying bread is transubstantiated into Christ’s body.1 Aquinas later explains how this can be said while the accidents remain.
Modern readers may find the terminology remote. That distance is part of the point.
The West did not merely love bread sentimentally. It built precise language to guard what happened to bread at the altar.
Macy and Rubin both show that medieval eucharistic doctrine developed through argument, devotion, and institutional practice.2
This history matters because it deepens the reflex. Bread is not only requested in prayer and received in rite. It is defended in metaphysical grammar.
That grammar will become important when the modern body raises medical questions.
Related sections: Natural Operations Remain; The Gluten Problem Foreshadowed.