December days: Filioque

ghoti prompted me with "Filioque. Go!", because clearly my darling wife wants to give me nice easy prompts that don't require much research or thought, or for that matter that don't cause me to play the priest-on-Trinity-Sunday game of "let's see how long I can talk for before accidentally committing heresy".

( so, there was this Cerularius, right, and he spilled our Humbert's pint )

This post is part of my December days series. Please prompt me!