St. Edmund Campion Catechism Group - Series 4 Lesson 6

Theology for Beginners: Chp 6. The Human Mind and the Doctrine of the Trinity
Theology for Beginners: All chapters
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
Summa Theologica: Prima Pars Q27-43
Companion to the Summa: Chp 7 The Inner Life of God

The Human Mind and the Doctrine of the Trinity


  1. Recap:

    Chapter 1: Why study theology?

    - Theology is wisdom which is the knowledge of all things in relation to their highest cause.

    - Theology is the greatest of all sciences by the sublimity of its object: God; and by the certitude of its conclusions: the certitude of faith.

    - Theology teaches us our finality: the finality of man is the supernatural perfection of all his faculties - the greatest among these are his intellect and will.

    - Theology helps us attain our finality in respect of ourselves by the perfect love of God.

    - Theology helps us attain our finality in respect of our neighbour: if we love God, then we love everything He loves.

    Chapter 2: Spirit

    - A spirit is an immaterial intelligent living being (types: God, the angels and the souls of men)

    - A soul is defined as the first principle of life of those material things which live (plants, animals and men). Plants, animals and men have souls, but only the souls of men are spirits.

    - Properties: a spirit does not change in its being, does not corrupt, does not die (and is therefore eternal), has no mass, no shape, and no place e say that spirits are subsistent, which means that they have all they need to exist - they do not need a body to exist (like a plant or animal soul).

    Acts: to know and love. No material organ is required for these activities.

    Chapter 3: The Infinite Spirit

    God is the Infinite Spirit. 

    - God is all knowing, all loving, all powerful

    - God is His own existence

    - God was not created, He does not change, He has no past and future, God perpeturally in the present.

    - God is naturally everywhere: by His essence (per essentiam), by His power (per potentiam), by His knowing (per scientiam)

    God is Actus Purus, He cannot ever be in potency to doing anything; He is His action.  St. Thomas says that He is Actus Purus – one , simple, infinite and perfect action which is always in the present.

    Chapter 4: The Blessed Trinity

    The Blessed 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. The Blessed Trinity is known only by revelation, but can subsequently be explored by reason.

    Chapter 5: The Three Persons

    In an attempt to understand as much as possible about the Blessed Trinity using revelation and our knowledge of the intellect and being (by the science of metaphysics), St. Thomas, building on theologians before him, makes a best attempt to reconcile the unity of God and the distinction of the Three Persons in God. God has one nature by which the Three Persons operate. The distinction of the Three Persons is discerned in the mutually opposed relations resulting from the act of God knowing Himself and loving Himself. The Persons, are distinguished as the subsistant relations or Paternity, Filiation and Passive Spiration.

    Most of us, however, do not have a sufficient grasp of metaphysics to understand this complex theory and so a simpler one is proposed: In the act of knowing Himself, God generates a mental Word which is identical to the Generator. In the generator we discern the Father, in the generated, we discern the Son. These are Persons Who will naturally love each other, this love being personified in the Holy Ghost

  2. Making the doctrine of the Trinity a living and loved reality

    For most people something like that happens when they embrace a mystery of the faith revealed to them by the Church:

     - first there is an intellectual response,

     - then a vital response,

     - then the doctrine possesses the mind, and the mind would be desolate without it.

  3. Intellectual response

    First an intellectual response: when we learn of the doctrine of the Trinity, our first feeling is intellectual satisfaction for having understood the model (if we ever do!), but it means little to us.

  4. Living response

    Further investigations bring the doctrine alive. On deeper understanding, we can see that God needs a fitting object for His infinite love. We finite beings, of course, are not a fitting objects to give full scope to God's love ("It is as though a man on a desert island had only a dog to love").  He must love Himself. It is only in the interchange of love with an equal that love reaches its height.  In the Trinity, the Three Persons form a community of love. Contemplating God we learn the secret of community, wonderfully defined by St. Augustine - a community is a multitude united in agreement about the things they love. Considerations such as these evoke a vital response.

  5. Loving response

    We might be pitiful objects of God's infinite love, but it is a property of a goodness to diffuse itself. He created us in love and He made us capable of love. His (subjective) redemption makes us loveable and inserts us into the infinite commerce of love in the Blessed Trinity by which we love God as One and Three with the same love that He loves Himself.