Question A: What is the origin of the infallibility of the Church?

1. Jesus chose apostles to be his companions and witnesses (see LG 19; AG 5). These apostles had a unique role as the authorized recipients of God’s revelation in Jesus, for the appropriation of all Jesus communicated by his words and deeds was essential to complete the relationship in which revelation consists (DV 7).

2. Divine truth is really present in the words and deeds of Jesus and communicated by them in a humanly accessible form. The content of revelation enters human experience in the material media of spoken words and observable behavior, and not in some other, mysterious way (20‑C). Jesus’ humanity, rather than hiding his divinity, expresses it (see 1 Jn 1.1–3). There is no room in this expression for error on his part, for his life reveals insofar as it is the medium of the activity of the Word (21‑F). Thus the apostles directly received God’s revealing acts and testimony (see DV 4): In seeing Jesus, they saw the Father (see Jn 14.9).

3. Faith has absolute certitude from the divine testimony which grounds assent to revealed truth (20‑E). Nevertheless, individual believers can make mistakes in matters of faith. For instance, St. Thomas Aquinas did not believe in Mary’s immaculate conception, mistakenly thinking it incompatible with the universality of Jesus’ redemptive work (see S.t., 3, q. 27, a. 2, ad 2). Such a mistake is possible without any defect either in divine revelation or in the individual’s faith, since individuals can err in identifying what does and does not belong to divine revelation—for example, by misunderstanding the content which is communicated (see S.t., 2–2, q. 11, a. 2, ad 3).

4. Could the apostles have made this sort of mistake, despite having immediate contact with Jesus? Humanly speaking, they could. They very often misunderstood Jesus during his mortal life. Peter himself, although he recognized Jesus with divinely given faith as the Messiah, proceeded to draw wrong conclusions from his imperfect grasp of Jesus’ mission (see Mt 16.13–23; Mk 8.27–33).

5. But Jesus promised and sent the Holy Spirit to assist the apostles (see Jn 14.16–17, 26; 15.26–27; 16.7–15; 20.21–22; Acts 1.5, 8; 2.1–4). The role of the Spirit and that of the apostles are parallel; both bear witness to Jesus and communicate the truth revealed in him (see Jn 15.26–27; S.t., 2–2, q. 6, a. 1). The Spirit reveals nothing new but brings about the apostolic appropriation of God’s revelation in Jesus (see Jn 16.13–15).¹

6. By this gift and only by it, God ensured that the apostles would and indeed could make no mistake in believing. Enlightened by the Spirit, they believed with absolute faith, itself a divine gift, all and only those things which God wished to make known to humankind through the life, death, resurrection, and ascension of the Lord Jesus.

The apostle has the Holy Spirit (see 1 Cor 7.40). The apostles together with the Spirit are witnesses to divine revelation in Jesus (see Acts 5.32; 15.28). To accept apostolic teaching is to obey God (see Acts 6.7; Rom 1.1–6). By the Spirit, Jesus fulfilled his promise to remain forever with the apostles (see Mt 28.20). God confirmed their work with many miracles (see Acts 2.43; 3.1–10; 5.12–16; 9.32–42; 19.11–12; and so on).

Hence it was not unreasonable to demand that humankind accept the apostolic witness as the very word of God (see Mt 10.40; Lk 10.16; Jn 13.20; 1 Thes 2.13). Given the infallibility of the apostles’ faith, the gospel they proclaimed could not possibly deviate from divine truth, and so it was not inappropriate to make the salvation or damnation of human persons hang upon their acceptance or rejection of apostolic testimony (see Mk 16.15–16).

7. In sum, not only did the apostles in fact make no mistake in their acceptance of revelation, it was not even possible for them to err in this. The exclusion of the possibility of error is what is meant by “infallibility.” Although the word “infallibility” only came into use in the Middle Ages, the reality understood by this concept and expressed by this word certainly was present in the apostles’ grasp of God’s revelation in Jesus.

8. That the apostles were infallible in believing and preaching does not mean that all of them believed and preached exactly the same things. The diversity of individuals in fact makes possible a more rich and complete revelation. Each apostle could appropriate and find meaning in particular words and deeds of Jesus which might have been overlooked by the others. The harmonious pluralism of apostolic faith is reflected in the unity in diversity of the New Testament which bears witness to that faith (see DV 19).

9. Thus, two things are true. First, any incompatibility among the beliefs of the different apostles was precluded by the unity of divine truth and the infallibility of the apostles in identifying what God revealed. Second, there nevertheless was need for their collegial unity and communication with one another so that they could proceed together in the full light of the whole of revealed truth. The apostles therefore conferred in Jerusalem (see Acts 15.1–29), and Paul submitted his preaching to the scrutiny of the other apostles “lest somehow I should be running or had run in vain” (Gal 2.2).

10. God’s revelation in Jesus is a concrete reality, comprised not only of statements of propositional truths but of the whole of Jesus’ human existence witnessed and shared in by the apostles. Thus, apostolic infallibility meant more than just the impossibility of making a mistake in identifying which propositions pertain to revelation and which do not. The apostles had also to be assisted so that they made no mistake in humanly appropriating other aspects of the personal revelation of Jesus. Without such assistance, human fallibility would have caused them to betray God’s revelatory intention by their methods of operating, patterns of worship, and communal structures. Revelation would more or less have failed.

11. In Jesus’ Church, apostles are primary (see 1 Cor 12.28; Eph 4.11); the Church is founded upon them, both at first and forever (see Eph 2.20; Rv 21.14).² Although the apostles were chosen to receive God’s revelation in our Lord Jesus, this revelation was not for them alone but for all humankind, to which they were commissioned to spread it (see Mt 28.20). After Pentecost, they faithfully carried out this commission. They and their associates also committed the message of salvation to writing and left successors to carry on the work (see DV 7).

Vatican II teaches concerning the apostolic foundation of the Church, and the true, inclusive meaning of the Church’s tradition: “Therefore the apostles, handing on what they themselves had received, warn the faithful to hold fast to the traditions which they have learned either by word of mouth or by letter (cf. 2 Thes 2.15), and to fight in defense of the faith handed on once and for all (cf. Jude 3). Now what was handed on by the apostles includes everything which contributes to the holiness of life, and the increase in faith of the People of God; and so the Church, in her teaching, life, and worship, perpetuates and hands on to all generations all that she herself is, all that she believes” (DV 8). It follows that to the extent that errors in belief and teaching can occur within the Church, these ought not to be attributed to the Church herself but rather to her individual members, whether they be popes, bishops, or others. The belief and teaching of the Church cannot err; beliefs and teachings within the Church can err, to the extent that they diverge from the norm of faith which is the common heritage of the Church as a whole.

12. Christian faith is not individualistic. Each believer enters into the faith of the Church: the apostolic, collegial grasp upon God’s revelation in Jesus.³ Hence, the Church as a whole enjoys the prerogative of the apostolic faith in which it shares: infallibility. Unity with the apostles makes it possible for the Church to continue to carry out Jesus’ mission through all generations (see AG 4–5).

13. The apostolic college, under Peter’s leadership, enjoyed infallibility in its belief in and preaching of divinely revealed truth. Others shared in this gift to the extent that they received Christian faith through the apostles and built up the Church on their foundation. The episcopal college, with the successor of Peter at its head, continues the work of the apostles; it enjoys their secure gift of communicating divinely revealed truth (see DV 8; LG 25; DS 3071/1837).⁴

14. Thus, the infallibility of the Church, taught by Vatican II, is based upon the infallibility of the college of the apostles. Individual members of the Church can make mistakes concerning what is and is not included in divine revelation, and so concerning what is and is not to be believed with divine faith. The Church as a whole can make no such mistake (see S.t., 2–2, q. 2, a. 6, ad 3; q. 5, a, 3, ad 2; q. 11, a. 2, ad 3). The absolute truth of God revealing, the absolute certitude of divine faith, and the unerring recognition by the Church of what pertains to faith converge to make the Church’s human belief and teaching enjoy and manifest the unerring quality of divine truth itself.

In its teaching on the Church as the People of God, Vatican II makes the point that the Church as a whole shares in Jesus’ prophetic office. Every member of the Church, not only bishops and priests, should bear living witness to Jesus, especially by living a Christian life and participating in the sacred liturgy. The Council then explains how the Church as a whole is equipped to do its work:

The body of the faithful as a whole, anointed as they are by the Holy One (cf. Jn 2.20, 27), cannot err in matters of belief. Thanks to a supernatural sense of the faith which characterizes the people as a whole, it manifests this unerring quality when, “from the bishops down to the last member of the laity” [note to St. Augustine omitted], it shows universal agreement in matters of faith and morals.
For, by this sense of faith which is aroused and sustained by the Spirit of truth, God’s people accepts not the word of men but the very word of God (cf. 1 Thes 2.13). It clings without fail to the faith once delivered to the saints (cf. Jude 3), penetrates it more deeply by accurate insights, and applies it more thoroughly to life. All this it does under the lead of a sacred teaching authority to which it faithfully defers. (LG 12; translation amended)

This unerring quality, which belongs to the Church as a whole, excludes not only the making of mistakes but the very possibility of being mistaken in these matters: “in credendo falli nequit.” “Matters of belief” includes moral norms: “de rebus fidei et morum.” This unerring quality is what elsewhere is called “infallibility.”

Thus Vatican II teaches that the Church as a corporate person is infallible in believing. This is not to say that the Church, even considered as a whole, lives up to its belief—that is another question. Nor is it to say that the laity as distinct from (much less as opposed to) the bishops enjoy infallibility in believing. Rather, the whole Church, including the bishops and under their leadership, including all who handed on the faith from the apostles and to whom we shall hand it on, clings to the faith unerringly, develops it, and applies it to life, thus bearing witness to divine truth and love. The Council continues in the same article to explain that the Spirit also enriches various parts and members of the whole Church with various appropriate gifts, to build up Jesus’ body. But judgment as to the genuineness and right use of such gifts also belongs to those who preside over the Church (see LG 12).

In recent years, “sensus fidelium” often has been used to suggest that opinions of the faithful have an independent value as a witness to moral truth, so that when these opinions diverge from received Catholic teaching, this divergence is a sign of a need for revision in the teaching. In response to this misunderstanding, John Paul II carefully interprets the teaching of Vatican II that the faithful at large discern truth through a supernatural sense of faith: “The ‘supernatural sense of faith’ [note omitted] however does not consist solely or necessarily in the consensus of the faithful. Following Christ, the Church seeks the truth, which is not always the same as the majority opinion. She listens to conscience and not to power, and in this way she defends the poor and the downtrodden. The Church values sociological and statistical research, when it proves helpful in understanding the historical context in which pastoral action has to be developed and when it leads to a better understanding of the truth. Such research alone, however, is not to be considered in itself an expression of the sense of faith.”⁵ The sense of faith of which the Council speaks characterizes the People of God as a whole; by this very fact one cannot discover it in dissenting opinions, no matter how many subscribe to them at a particular time and place.

Writing to the Corinthians, St. Paul asserts that whether one is led by the Spirit can be detected from the faith one professes (see 1 Cor 12.3). The word of God did not come from the people; they must conform to it: “If any one thinks that he is a prophet, or spiritual, he should acknowledge that what I am writing to you is a command of the Lord. If any one does not recognize this, he is not recognized” (1 Cor 14.37–38). Salvation depends upon standing firm in the faith one received (see 1 Cor 15.1–2). Jesus is present in the Church (see LG 14), teaching through the apostle himself, for the apostle was made “teacher of the Gentiles in faith and truth” (1 Tm 2.7). Christians must hold fast to the faith (see Col 1.23), for it communicates Jesus, the fullness of wisdom (see Col 1.28). They must beware of being deceived by seductive philosophy which comes from human traditions (see Col 2.6–8). As children of God, Christians learn through apostolic instruction “how one ought to behave in the household of God, which is the church of the living God, the pillar and bulwark of the truth” (1 Tm 3.15).

As long as—but only as long as—individual Christians think with the Church, they share in its unerring sense of faith and enjoy the support and defense of this pillar and bulwark. For “the Spirit expressly says that in later times some will depart from the faith by giving heed to deceitful spirits and doctrines of demons, through the pretensions of liars whose consciences are seared” (1 Tm 4.1–2). Those who are misled have failed to obey the truth; if they had not disobeyed, they would have remained firm in the faith, for it is an indestructible seed, “the living and abiding word of God” (1 Pt 1.23).⁶

1. See Ignace de la Potterie, S.J., and Stanislaus Lyonnet, S.J., The Christian Lives by the Spirit (Staten Island, N.Y.: Alba House, 1971), 62–68.

2. See International Theological Commission, “Apostolic Succession: A Clarification,” Origins, 4 (19 September 1974), 193, 195–200.

3. For a powerful development of the original character of institutionalism in Christianity, see B. C. Butler, O.S.B., “Spirit and Institution in the New Testament,” Studia Evangelica, 3 (1961), Texte und Untersuchungen, 88, ed. F. L. Cross (Berlin: Akademie-Verlag, 1966), 138–65.

4. For an interpretation of a phrase which has been used to refer to infallibility (see DS 3071/1837; DV 8), see Jerome D. Quinn, “ ‘Charisma Veritatis Certum’: Irenaeus, Adversus Haereses 4, 26, 2,” Theological Studies, 39 (1978), 520–25. For a clarification of the concept of apostolic tradition, developed by St. Irenaeus, and the continuity of the apostolic faith in the Church through the succession of bishops, see Jean Daniélou, A History of Early Christian Doctrine before the Council of Nicaea, vol. 2, Gospel Message and Hellenistic Culture, trans. John Austin Baker (London: Darton, Longman and Todd, 1973), 139–56.

5. John Paul II, Familiaris Consortio, 74 AAS (1982) 85–86; Eng. ed. (Vatican City: Vatican Polyglot Press, 1981), 10–11 (sec. 5). A full theological treatment of this matter: Jesús Sancho Bielsa, Infalibilidad del Pueblo de Dios: “Sensus fidei” e infalibilidad organica de la Iglesia en la Constitucion “Lumen gentium” del Concilio Vaticano II (Pamplona, Spain: EUNSA, 1979).

6. For further clarification of “sense of the faithful”: Hans Urs von Balthasar, Elucidations, trans. John Riches (London: SPCK, 1975), 91–98.