Fascinating thing, Papal Infallibility. It only became official Catholic doctrine in 1870. Yup, whatever they believed in the Middle Ages, it was only formally adopted as dogma less than 150 years ago. In that sense it's newer than The Origin of Species, Clark Maxwell's realisation that light and electro-magnetism are a single phenomenon, The Communist Manifesto, the invention of the Periodic Table and a trans-Atlantic cable for telegraphy. Welcome to the modern world. db