Catholic Treasury Network
Catholic Theology · For seminarians, teachers, and the curious

Why does the Church teach this?

The questions Catholics get asked — and the answers as the great seminary manuals explain them. Pohle-Preuss as the spine, Glenn's Tour of the Summa as your bridge to Aquinas, and the major encyclicals in context.

Common questions

Each question opens the tract where Pohle-Preuss treats it in full.

psychology Does God exist? How can we know? arrow_forward all_inclusive Why do Catholics believe in the Trinity? arrow_forward church What did Christ accomplish on the Cross? arrow_forward star Why pray to Mary? Why honour the saints? arrow_forward wb_sunny How does grace actually work in the soul? arrow_forward celebration What really happens at Mass? arrow_forward balance How does the Church teach about morality? arrow_forward account_balance Why is there a Pope? arrow_forward hourglass_empty What happens after we die? arrow_forward

The sixteen tracts

The traditional division of Catholic theology — Apologetics first, establishing the rational grounds for Revelation, then the dogmatic tracts with Pohle-Preuss as their spine.

Tract I
Apologetics

The rational preamble to Faith — Revelation's possibility, the motives of credibility, the testimony of Christ, and the nature and grounds of Faith itself. Drawn from Walshe's Principles of Catholic Apologetics and Wilhelm-Scannell's Manual, Vol. I.

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Tract II
God: His Existence & Attributes
Pohle Vol. I · Summa I, QQ. 2–26

God's existence and attributes — the proofs from reason, divine simplicity, perfection, and unity.

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Tract III
The Blessed Trinity
Pohle Vol. II · Summa I, QQ. 27–43

One God in three Persons — processions, relations, and missions.

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Tract IV
Creation & the Supernatural Order
Pohle Vol. III · Summa I, QQ. 44–119

God as Creator; the angels; man's body and soul; original justice and original sin.

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Tract V
Christology
Pohle Vol. IV · Summa III, QQ. 1–26

The Person of Christ — the Incarnation, hypostatic union, two natures.

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Tract VI
Soteriology
Pohle Vol. V · Summa III, QQ. 46–52

The work of Christ — redemption, satisfaction, merit.

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Tract VII
Mariology
Pohle Vol. VI

Divine motherhood, perpetual virginity, Immaculate Conception, Assumption.

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Tract VIII
Grace
Pohle Vol. VII · Summa I-II, QQ. 109–114

Actual grace, sanctifying grace, justification, and merit — the supernatural life of the soul.

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Tract IX
The Sacraments in General, Baptism, and Confirmation
Pohle Vol. VIII · Summa III, QQ. 60–72

The general theology of the sacraments — matter, form, causality, effects — followed by Baptism and Confirmation.

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Tract X
The Holy Eucharist
Pohle Vol. IX · Summa III, QQ. 73–83

The Real Presence, transubstantiation, and the Mass as the perpetual re-presentation of the Sacrifice of the Cross.

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Tract XI
Penance
Pohle Vol. X · Summa III (Suppl.), QQ. 1–28

Contrition, confession, satisfaction, and the power of the keys.

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Tract XII
Extreme Unction, Holy Orders, and Matrimony
Pohle Vol. XI · Summa III (Suppl.), QQ. 29–68

Extreme Unction for the sick and dying, Holy Orders for the Church's ministers, and Matrimony for the Christian family.

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Tract XIII
Moral Theology
Summa I-II & II-II

Conscience, law, sin, the virtues and vices, the Decalogue.

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Tract XIV
Ecclesiology
Wilhelm-Scannell Vol. 2

The Church — her nature, marks, authority, infallibility, and the papal primacy.

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Tract XV
Eschatology
Pohle Vol. XII · Summa Suppl., QQ. 69–99

Death, judgement, heaven, hell, purgatory, the resurrection of the body.

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Tract XVI
Spiritual Theology
Tanquerey

The purgative, illuminative, and unitive ways; prayer; perfection.

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Featured magisterial documents

Encyclicals and conciliar documents that shaped how the Church teaches each tract. Each précis is one screen — read in five minutes, link to the full Vatican text.

Benedictus Deus
Benedict XII · 1336

Defines as dogma that the souls of the just enjoy the beatific vision immediately after death (or after purgation), and that the damned descend to hell immediately — settling the controversy over the interim state of souls before the General Judgement.

Dei Filius
Vatican Council I · 1870

Defines the Catholic doctrine on God the Creator, on divine revelation, on faith and reason, and on the relationship between faith and science — establishing the dogmatic foundations that all subsequent theology presupposes.

Pastor Aeternus
Vatican Council I · 1870

Defines the dogma of papal primacy of jurisdiction over the universal Church and papal infallibility when the Pope speaks ex cathedra on matters of faith and morals.

Aeterni Patris
Leo XIII · 1879

Restores the philosophy and theology of St Thomas Aquinas as the Church's authoritative intellectual method — inaugurating the Thomistic revival within which Pohle, Tanquerey, and the entire modern manual tradition write.

Rerum Novarum
Leo XIII · 1891

The founding document of Catholic social teaching — addressing the condition of workers, the right to private property, the just wage, and the proper roles of the state, the Church, and voluntary associations.

Mystici Corporis Christi
Pius XII · 1943

Defines the Church as the Mystical Body of Christ — a visible, hierarchical society animated by the Holy Spirit and governed by the Pope as Vicar of Christ.

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New to Catholic theology?

A clear path for a complete beginner.

  1. Start with the Penny Catechism on Catholic Treasury — the answers in their simplest form.
  2. Read Glenn's Tour: Q.2 — The Existence of God — Aquinas's Five Ways made accessible.
  3. Explore the Grace tract — the most complete on the site, with all 23 of Pohle's chapters.
  4. Dei Filius on the relationship of faith and reason — short, definitive, and clarifying.
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"Theology is taught by God, teaches of God, and leads to God."
— St Thomas Aquinas, Summa Theologica I, Prologue