Our Lord invested His Church with a doctrinal authority enabling her to teach with infallible certainty all that He has revealed. "And I will ask the Father: and he shall give you another Paraclete, that He may abide with you for ever: the Spirit of truth, Whom the world cannot receive, because it seeth Him not, nor knoweth Him." (John 14: 16-17). "He that heareth you heareth Me" (Luke 10: 16). The Church is "the pillar and ground of the truth" (I Tim. 3: 15).

Infallibility is the impossibility of falling into error. The Church is infallible in her office of teaching, owing to the perpetual assistance of the Holy Ghost promised to her by Our Lord, when, either in the exercise of her Ordinary and Universal Magisterium, or by a solemn pronouncement of the supreme authority, she proposes, for the acceptance of all, truths of faith or morals that are either revealed in themselves or connected with revelation. The supreme authority of the Church, her Extraordinary Magisterium, can be exercised by the Roman Pontiff when he speaks ex cathedra,that is, when by virtue of his supreme apostolic authority, he defines a doctrine regarding faith or morals to be held by the universal Church. The definitions of a General Council also constitute an exercise of the Extraordinary Magisterium and are infallible, providing they are ratified by the Pope. But the Pope does not require the ratification of a General Council or of the bishops of the Church for his own definitions. Pastor Æternus, the First Dogmatic Constitution on the Church of Christ of the First Vatican Council, teaches that "such definitions of the Roman Pontiff are irreformable of themselves, and not in virtue of the consent of the Church."

Pastor Æternus declared the extent of infallible teaching to be the same for the Pope and the Church. Some Catholics imagine that all the teaching of the Extraordinary Magisterium is infallible automatically. This is not correct. Pastor Æternus restricts this assistance to definitions, and these definitions must be concerned with faith or morals (in definienda doctrina de fide vel moribus). The definition must bind the Universal Church (ab universa Ecclesia tenendam definit). Decrees which bind only part of the Church are not definitions: but only those which command the assent of all the faithful. The definition must constitute an explicit final, and irrevocable judgement, binding the entire Church to an irrevocable internal assent. A definition does not need to be imposed under pain of anathema in order to be infallible, although this is a common method of indicating that the supreme authority has made a final decision. All that is necessary is that it should be the clear intention of the supreme authority to settle the matter forever. This is because no believer who pays due attention to Christ's promises can refuse to assent with absolute and irrevocable certainty to a definition of the Extraordinary Magisterium. Teaching which must be accepted with this degree of certainty is referred to as of divine and Catholic faith (de fide divina et catholica). A truth thus defined is a "Dogma of the Faith", and its pertinacious rejection is called "heresy". (A detailed examination of the nature of heresy is provided below).

In its Dogmatic Constitution Dei Verbum, the First Vatican Council taught that: "All those things are to be believed with divine and Catholic faith which are contained in the word of God, written or handed down, and which the Church, either by a solemn judgement or by her ordinary and universal teaching (Magisterium), proposes for belief as having been divinely revealed." Infallible teaching is not, therefore, confined to pronouncements of the Extraordinary Magisterium. All that is necessary is an indication of the manifest will of the bishops, teaching in union with the Pope, either assembled in a general council or scattered throughout the world, to propose a teaching of faith or morals as one which must be held by all the faithful.

Although a Catholic incurs ipso facto excommunication only by the pertinacious denial of doctrine that is de fide divina et catholica, he is bound in conscience to receive other doctrinal decrees concerning faith and morals that are issued by the Apostolic See, because of the obedience we owe to that See which exercises an authority given to it by Christ. This non-infallible teaching on faith and morals must be accepted not simply with an absence of external opposition, that is a reverent silence (silentium obsequiosum), but with an inner assent (assensus internus). By way of exception, the obligation of inner agreement may cease if a competent expert, after a renewed scientific investigation of all grounds, arrives at a positive conviction that the decision rests on error. Such an exception could apply only to teaching which was in itself a novelty and appeared impossible to reconcile with previous authoritative teaching. The ordinary and usual form of the papal teaching authority is not infallible, neither is the teaching of the Roman Congregations. It is of interest to note that the teaching of the Second Vatican Council contained no infallible definitions, and any teaching in its documents that is binding de fide divina et catholica possesses this status in virtue of some previous infallible pronouncement, and not because it is included in a Vatican II document.

© 1997 Michael Davies.

Last modified 27th October, 1997, by David Joyce.