I’m wondering about the filioque. I know it’s the part of the creed that refers to the procession of the Holy Spirit from the Son. I also know it is used frequently by the Orthodox Churches as a reason (among others) why they are not willing to pursue re-communication with the Church in Rome.
When/why did the filioque get added to the Nicene Creed? I assume that we Catholics don’t regard it as a change, but as a clarification of something we already believed.