Certain SainthoodThe doctrine of papal infallibility is a central tenet of Roman Catholicism, and yet it is frequently misunderstood by Catholics and non Catholics alike. Much of the present day theological discussion points to the definition of papal infallibility made at Vatican I in 1870, but the origins of the debate are much older than that. In Certain Sainthood, Donald S. Prudlo traces this history back to the Middle Ages, to a time when Rome was struggling to