(RNS) — It was after the Second Vatican Council in 1965 that the reactionary Catholic movement known as sedevacantism arose. It took its name from the Latin phrase sede vacante (“while the ...

So I don’t see the text from Vatican I as being a useful argument against sedevacantism in general, but there is another possibility. Might it work against a specific form of sedevacantism?

Hutton Peter Gibson was an American conspiracy theorist, Holocaust denier, and also a well-known writer of sedevacantism. For those unversed, sedevacantism is the belief that since 1958, the world ...