In his 2017 lecture to which I referred a little while ago, Dr Nichols, according to the Catholic Herald, said that the First Vatican Council had restricted the doctrine of papal Infalibility, so that it is not the position of the Roman Catholic Church that a pope is incapable of leading people astray by false teaching as a public doctor. He went on:
"He may be the supreme appeal judge of Christendom ... but that does not make him immune to perpetrating doctrinal howlers. Surprisingly, or perhaps not so surprisingly given the piety which has surrounded the figures of popes since the pontificate of Pius IX, this fact appears to be unknown to many who ought to know better".
The Catholic Herald added that Fr Aidan went on to wonder whether "given the limits of papal infallibility, canon law might be able to accommodate a formal procedure for inquiring into whether a pope had taught error" and "a procedure for calling to order a pope who teaches error". Such a procedure might be less "conflictual", Fr Nichols added, if it took place during a future pontificate, rather as Pope Honorius was only condemned for error after he had ceased to occupy the chair of Peter.
Such a process would "dissuade popes from any tendency to doctrinal waywardness or simple negligence."