Dei Filius
Dei Filius is Vatican I's 1870 Dogmatic Constitution on the Catholic Faith, treating God, revelation, faith, reason, and their proper relationship.[1]
Overview
Dei Filius is the incipit of the dogmatic constitution of the First Vatican Council on the Catholic faith, which was adopted unanimously, and issued by Pope Pius IX on 24 April 1870.
The constitution set forth the teaching of "the holy Catholic Apostolic Roman Church" on God, revelation and faith.[2]
Revelation and faith
Dei Filius confesses the one living God as creator of all things and teaches that God can be known with certainty from creation by the natural light of human reason. Supernatural revelation remains necessary so that divine truths accessible to reason can be known by all readily, firmly, and without admixture of error, and so that mysteries beyond reason can be known at all.
Faith is a supernatural virtue by which, aided by grace, people believe what God has revealed because of the authority of God who reveals. The constitution affirms motives of credibility without reducing faith to a conclusion forced by historical evidence.
Faith and reason
The document rejects both rationalism, which subjects revelation to unaided reason, and fideism, which denies reason's real capacity and the rational credibility of faith. Truth cannot contradict truth; apparent conflicts arise from misunderstanding the faith or from opinions mistakenly treated as conclusions of reason.
Its chapters and attached canons contain solemn conciliar teaching, including dogmatic definitions. They should be read in their nineteenth-century controversies and together with later magisterial development, especially Dei Verbum and Fides et ratio.[3]
Content
The dogmatic constitution "deals with faith, reason, and their interrelations".[4]
The document begins by observing that "God, the principle and end of all things, can be known with certainty by the natural light of human reason from created things".[5] However, it then explains that, through divine revelation, this knowledge can more easily be attained "with firm assurance, and with no admixture of error".[6]
Faith and reason are seen as complementary. Following Thomas Aquinas, whose guiding thought Philip Egan paraphrases as that "it is the same God who grounds all truth, whether secular or divine, and the truth is ultimately one",[7] Dei Filius said
there can never be any real discrepancy between faith and reason, since the same God who reveals mysteries and infuses faith has bestowed the light of reason on the human mind; and God can not deny himself, nor can truth ever contradict truth. The false appearance of such a contradiction is mainly due, either to the dogmas of faith not having been understood and expounded according to the mind of the Church, or to the inventions of opinion having been taken for the verdicts of reason.[8]
Name used for the church
The draft presented to the council on 8 March 1870 drew no serious criticism. But a group of 35 English-speaking bishops, who feared that the opening phrase "Sancta Romana Catholica Ecclesia" might be construed as favouring the Anglican branch theory, raised objections to this expression, "Holy Roman Catholic Church". They proposed that the word "Roman" be omitted out of concern that use of the term "Roman Catholic" would lend support to proponents of branch theory. While the council overwhelmingly rejected this proposal, the text was finally modified to read "The Holy Catholic Apostolic and Roman Church".[9]
The words "Sancta Romana Catholica Ecclesia" were voted on three separate dates. On the first occasion, when this chapter alone was considered, two votes concerned the opening words. The first was on a proposal by a few English-speaking bishops to delete the word "Romana", thus changing "Sancta Romana Catholica Ecclesia" (The Holy Roman Catholic Church) to "Sancta Catholica Ecclesia" (The Holy Catholic Church). This was overwhelmingly defeated.[10][11]
The second vote, held immediately afterwards, was on a proposal to insert a comma, so that "Sancta Romana Catholica Ecclesia" (The Holy Roman Catholic Church) would become "Sancta Romana, Catholica Ecclesia" (The Holy Roman, Catholic Church). This too was defeated, though not as overwhelmingly as the first proposal.
In a later vote, held on 12 April 1870, the text as a whole, which preserved the same opening words, was approved with 515 affirmative votes (placet) and no opposing votes (non placet); but there were 83 placet iuxta modum votes, asking for retouches, many of them regarding the opening words of chapter I.[12][13]
In view of the reservations thus expressed, the text presented for a final vote and approved unanimously on 24 April changed the order of the words and added "Apostolica", so that "Sancta Romana Catholica Ecclesia" became "Sancta Catholica Apostolica Romana Ecclesia" (The Holy Catholic Apostolic Roman Church).[14]
Legacy
The Second Vatican Council's Dogmatic Constitution on Divine Revelation (Dei verbum, 1965) presented itself as "following in the footsteps of the Council of Trent and of the First Vatican Council" and made a number of references to Dei Filius.[15]
See also
References
- Back to citation Decrees of the First Vatican Council — Dei Filius and its canons in the Tanner translation.
- Back to citation Roberto De Mattei, John Laughland, Pius IX, p. 137
- Back to citation Fides et ratio — John Paul II's authoritative development of the relationship between faith and reason.
- Back to citation "First Vatican Council | Description, Doctrine, & Legacy". Encyclopedia Britannica. Retrieved 2020-02-19.
- Back to citation Pope Pius IX, Dei Filius, Chapter II
- Back to citation Trabbic, Joseph (23 October 2012). "Vatican I and God's natural knowability". Philosophy at AMU. Archived from the original on 7 October 2017. Retrieved 2020-02-19., cf. Second Vatican Council (1965), Dei Verbum, article 6, accessed on 23 August 2025
- Back to citation Egan, Philip A. (2017), Philosophy and Catholic Theology: A Primer, Liturgical Press, no pagination ISBN 9780814683538
- Back to citation Dei Filius, 1870, Chapter IV
- Back to citation Avery Dulles (1987), The Catholicity of the Church, Oxford University Press, p. 131, ISBN 0-19-826695-2
- Back to citation Richard Faber. Katholizismus in Geschichte und Gegenwart. 2005, p. 42
- Back to citation Theodorus Granderath. Constitutiones Dogmaticae Sancrosancti Oecumenici Concilii Vaticani. (Herder 1892), p. 5 indicates that the vote was overwhelming. Granderath's book was called "one of the most important contributions to the literature of dogmatic theology in our day" in a review in the American Ecclesiastical Review.
- Back to citation Granderath, p. 27
- Back to citation Jean-Yves Lacoste, Encyclopedia of Christian Theology: G - O (CRC Press, 2005 ISBN 1-57958-250-8, ISBN 978-1-57958-250-0), p. 1666
- Back to citation Jean-Yves Lacoste, Encyclopedia of Christian Theology: G - O (CRC Press, 2005 ISBN 1-57958-250-8, ISBN 978-1-57958-250-0), p. 1666; Granderath, pp. 29-32; Lacoste, Jean-Yves (2004). "Vatican I, Council of". Encyclopedia of Christian Theology. New York: Routledge. p. 1666. ISBN 1-57958-250-8.
- Back to citation Holy See, Dogmatic Constitution on Divine Revelation, Preface and citations listed in concluding notes, published on 18 November 1965, accessed on 22 August 2025