I FULLY understand the term. Although in the Christian era, ex cathedra took on the meaning of the Pope speaking from the chair and the infallibility that goes with it, in earlier times Hebrews used the term to refer to Moses. In common terms, ex cathedra takes on the meaning of any official speaking from his office on official degree. Even the Oxford Dictionary defines it as "with the full authority of office". See, now YOU have learned something that you did not know.