I'm in a very annoying argument with a novus ordite trying to convince him that it's protestant in nature. I mentioned that prayer in common with heretics had been formally anathematized, but now I'm unable to verify the source. I find it all over the internet, the same quote, sometimes saying it was from the council of Carthage, sometimes saying it is can. 63 sometimes can. 64. Which code of canon law would that be? Can't locate a primary source. Can anyone assist here?
Thanks