Carvings on the interior walls of the nave, a 'sermon in stone'.

Unlike the carvings in the clerestory, those mounted at the springers of the arches of the nave are hard to miss. Near the eastern end of the arcades are the heraldic shields of Bishop John Marshall, who died in 1495, and facing it, on the northern side, that of the de Roos surmounted by the peacock emblem of de Roos (later adopted by the Earls of Rutland). Right at the eastern end are a woman (or a priest?) to the south and a king on the northern side, gazing at each other while their bodies seem to be sliding down the stonework.

The other figures in the nave are all of monstrous creatures. Although today we might look at these as works of art in their own right, this was not the objective of their creators. They were there to provide moral guidance for medieval viewers. They are literally “sermons in stone” intended to demonstrate the belief that the world itself was the Word of God, and that every living thing has its own special meaning within Creation, a book of nature designed by God as a source of instruction for humanity. This idea was partly based upon biblical studies but mostly upon one of the most popular of medieval books, the Bestiary or Bestiarum Vocabulum.