St. Edmund Campion Catechism Group - Series 2 Lesson 16 & 17


Podcast: The True God is a Trinity, The Holy Trinity at Mass
Podcast: Notes

Magisterium: Council of Nicea 325, Athanasian Creed

Penny Catechism: Q25-30
Catechism of the Council of Trent (The Roman Catechism): The Creed Art.1
Bible: Lk 1:32&35, Jn 15, Mt 28:19
Catholic Encyclopedia: The Blessed Trinity
Aquinas 101: The Triune God, The Persons of the Trinity, The Missions of the Trinity
Pints with Aquinas: 
Edward Feser: 
Summa Theologica: Prima Pars Q27-43
Companion to the Summa: Chp 7 The Inner Life of God

The Blessed Trinity

  1. Introduction:

    - Faith: Faith is the supernatural virtue which renders the intellect entirely obedient to the will when God reveals a truth, because of the authority of God revealing.

    - Reason: The act by which the conclusion of a demonstration is reached.

    Knowledge of God: We can know God by faith and reason.

       - Divine Revelation (Scripture and Tradition) is the source of the knowledge of God by faith.

       - Observation of the natural world gives us knowledge of God by reason.

       - Theology (Divine Revelation unpacked by reason) gives us knowledge of God by both faith and reason.

     - Nature of God: God is defined as ipse esse subsistens (subsistent being existing of Himself) or Actus Purus (Pure Act). God is in potential to nothing because He is everything: "I am Who am."

  2. Quid Sit Dogma Trinitatis?

    The Holy Trinity is the term used to express the central doctrine on the Christian religion: the truth that in the unity of the Godhead there are Three Persons, the Father, the Son and the Holy Ghost, these Three Persons being truly distinct from one another. There is one being, with one nature and there are Three Persons.


  3. Knowledge of the Trinity

    We know the Trinity from the two sources of Revelation:

    - From Scripture: First Jesus taught his disciples to recognise in Himself the Eternal Son of God.

    9 As the Father hath loved me, I also have loved you. Abide in my love. 10 If you keep my commandments, you shall abide in my love: as I also have kept my Father's commandments and do abide in his love. (Jn15)

    When His ministry was drawing to a close, He promised that the Father would send them another Divine Person, the Holy Spirit, in His place.

    26 But when the Paraclete cometh, whom I will send you from the Father, the Spirit of truth, who proceedeth from the Father, he shall give testimony of me. (Jn15)

    Finally after the resurrection, He revealed the doctrine in explicit terms, bidding them:

    Going, therefore, teach ye all nations, baptizing them in the name of the Father, and of the Son, and of the Holy Ghost. (Mt 28:19)

    - From Tradition: 

    The first baptismal formula, using the words of Christ himself, clearly express the Godhead of the Three Persons.   

      -  The doxologies from the earliest writings of the Fathers indicate clearly the doctrine of the Trinity which is in the now universal form: Glory be to the Father.. 

      -  In the Mass, references are repeatedly made to the Trinity

      -  The battle against the Arian heresy in the fourth century caused the doctrine of the Holy Trinity to be perfectly defined (Council of Nicea 325) …but never understood FOR IT IS A MYSTERY.


  4. The Doctrine Of The Holy Trinity Is A Mystery

    The doctrine of the Holy Trinity is a mystery, it cannot be understood by reason:

    - we cannot see it- we cannot imagine it.

    It is a perplexing mystery:

    - how is it that the Three Persons are not three beings but one Being?

    - How is it that Three Persons are distinct but none have something that the other hasn’t got?

  5. The greatest minds for two thousand years have reflected on the mystery, have tried to penetrate it, have tried to understand it. In the end they end their endeavour by simply gazing in wonder and adoration.

    Walter Farrell OP in his Companion to the Summa has this to say of the mystery of the Blessed Trinity

    The Trinity is a mystery; no doubt about it. Unless we had been told of its existence, we would never have suspected such a thing. Moreover, now that we know that there is a Trinity, we cannot understand it.

    The man who attempts to unravel the mystery is in the position of a near-sighted man straining his eyes from the Eastern Shore of Maryland for a glimpse of Spain.

    We cannot probe the depths of the ocean of divinity with the foot-rule of the human intellect.

    It may feel grand to adopt a righteously indignant attitude against mysteries, snatch up a hatchet and sally forth as a crusader dedicated to smashing the dark windows behind which mystery carries on its revels. But why not start the crusade at home?

    Long before we have finished in nature, our hatchet will be dulled, our arm fatigued, our soul humbled enough to see that there are undreamed of truths in this world; let alone the undreamable truths in the world of divinity.

    What, for instance, do we know of electricity beyond the fact that it works and something of how it works?

    - There is very much to be explained about radio.

    - We do not understand gravity.

    - The further we look into space or the more minutely we look into matter the more mystified we become.

    - And then we come to living beings, the simplest cell of which we can only sketch the outlines.

    And so on. yet we are surprised, indignantly surprised, that the divinity should propose truths beyond the capacities of our minds!

    Ordinary common sense should tell us that this is to be expected because of the inevitable limitations of our nature.

    A small cup can hold only so much water; not the whole ocean. As our eyes are only human eyes, our ears only human ears, so our intellects are only human intellects; there are truths we cannot know by those intellects.


  6. Why God Has Revealed This Mystery?

    But why does God wish to reveal things that we cannot understand? What’s the point? If God has given us a finite intellect, why give us something infinite that we can never compass?

    The answer to this question is not unfathomable like the mystery:

    - we were made for God, for union with Him;

    - we were made for something beyond ourselves, beyond this material world, beyond our comprehension.

    - God revealed Himself to us, not so that we could comprehend Him (fully understand Him) with our minds in the light of reason, but to see Him in the light of supernatural faith: dimly it is true, but nevertheless see Him way beyond the capacity of our reason.

    And in that act of faith:

    - we see our Goal,

    - we see the Power of God, the Wisdom of God, and the Love of God,

    - and should we turn to this God revealing Himself, we are taken-up to participate in this Divine activity of God knowing and loving Himself. We are taken up to dwell in the Trinity.

    God revealed the mystery of His unique nature shared by Three Divine Persons so that we might begin to share and grow in that Life which is the Divine Life for which we were called, that we might begin the glory which, by God’s grace and mercy will be consummated in heaven.

    We must understand that the Trinity is not to be believed simply to enable us to attain heaven more readily, but to be believed as a condition of heaven.

    The creed attributed to St. Athanasius which all those who are held to recite the Divine Office will on Trinity Sunday, makes this clear. It begins:

    Whosoever will be saved, before all things it is necessary that he hold the catholic faith. Which faith unless every one do keep whole and undefiled, without doubt he shall perish everlastingly. And the catholic faith is this: that we worship one God in Trinity, and Trinity in Unity.


  7. How much can know of the Trinity by reason?

    As we can know certain attributes of God by reason alone, we can apply this knowledge to the Blessed Trinity which is revealed to us. For example:

    - As beings act by their nature, we know that all three Persons act by the one Divine Nature. When that Divine Nature acts in creation, all the three Persons act together.

    - Similarly, where God is present in both the natural order and the supernatural order, all three Persons are present together (eg. by sanctifying grace in the soul, even in the Blessed Sacrament).

    - The distinction between the three Persons is not a distinction of being, but of relation (this is deep metaphysics, so don't worry if you don't understand yet).


  8. St. Thomas's best attempt to describe the Trinity.

    St. Thomas Aquinas, is recognised having penetrated the Mystery to the furthest degree. By trying to use what we see in nature to understand how the apparent contradictions of the doctrine might be reconciled, he saw in the Godhead, the eternal act of God knowing Himself and God loving Himself from whence the Three Persons are distinguished.

    His exposition (not an explanation) can be summarised by the following statement: "I LOVE MYSELF".

    God, Who is the Supreme Being - infinite in all His perfections - naturally loves Himself. [For us, mere creatures, we do the same but often loving what is not perfect or what is not existent in ourselves.] When God loves Himself, as He has done for all eternity:

    - the “I” is the Father who is the act of thinking;

    - the “Myself” is the generated mental Word which is the same as the Father and, as it is being generated, it is the Son;

    -  and the "Love" that exists between the Father and the Son is an infinite act which is also God, this infinite act is the Holy Ghost.

    These three words: I, LOVE and MYSELF are the key to lifting the corner of the veil which covers the Blessed Trinity - a veil which shall take an eternity to remove for those who enjoy the Beatific Vision.