— Sanctum Catholic Apologetics —

Sed Contra.

On the contrary — the answer to every counter-claim against the Catholic Church.

Primary sources only · Always free

What this is

Sed Contra is a structured Catholic apologetics engine. For every Protestant, Eastern Orthodox, Mormon, atheist, Muslim, or Jewish counter-claim against Catholic teaching, it surfaces the Catholic answer with verbatim citations to the primary source — Scripture in the original languages, the Catechism, the ecumenical councils, the Church Fathers, the magisterial documents — never to a modern apologist's paraphrase.

The structure follows St. Thomas Aquinas's Summa Theologiae: the Catholic position, the strongest objection, the answer, then the counter-objection that an opponent will raise next, then the answer to that. Recursive. Citation-grounded. Five and six levels deep. An honest debate tree, not a list of talking points.

Built also for the AI-counter loop: when a user pastes a Catholic answer into ChatGPT or Grok or Gemini and asks for a refutation, the AI's likely refutation is already in the tree, with the Catholic counter-counter already cited. The engine plays chess against artificial intelligence, not against human apologists.

— Six Traditions —

Protestant

~165 claims

Wave 1 in build

Atheist

~84 claims

Wave 3

Eastern Orthodox

~61 claims

Wave 4

Islam

~41 claims

Wave 5

LDS

~25 claims

Wave 6

Judaism

~29 claims

Wave 7

— Wave 1 · Protestant Big Five —

DEMO LIVE

Sola Scriptura

— Sola Scriptura, Sola Traditio? —

The foundational Reformation claim: Scripture alone is the infallible rule of faith. The 16-claim cluster Catholic apologetics has answered for 500 years. Built six levels deep.

Open the debate tree  →

16 distinct counter-claims · 12+ primary sources · 6-level recursive depth
QUEUED

The Papacy

— Tu es Petrus —

"On this rock I will build my Church." The 14-claim cluster: from Matthew 16 exegesis through Vatican I, Honorius, Vigilius, conciliarism, and Newman's development of doctrine.

Coming next

14 distinct counter-claims · in build queue

QUEUED

The Real Presence in the Eucharist

— Hoc est enim corpus meum —

The 10-claim cluster: John 6, the Last Supper accounts, the pre-Nicene Fathers, transubstantiation as Aristotelian metaphysic, Berengar of Tours, the Mass as ephapax sacrifice.

Coming next

10 distinct counter-claims · in build queue

QUEUED

Marian Dogmas

— Theotokos · Immaculata · Assumpta —

The 18-claim cluster: Theotokos at Ephesus 431, the Immaculate Conception (Pius IX 1854), the Assumption (Pius XII 1950), perpetual virginity, intercession, hyperdulia.

Coming next

18 distinct counter-claims · in build queue

QUEUED

Justification

— Sola Fide? —

The 8-claim cluster: Romans 3:28, James 2:24, Trent Session VI, imputed vs. infused righteousness, the 1999 Joint Declaration, mortal/venial sin, assurance.

Coming next

8 distinct counter-claims · in build queue

PLUS 11 MORE CLUSTERS

Then everything else.

— Quid plura? —

Purgatory · indulgences · apostolic succession · sacraments · icons · saints · ecclesiology · clerical celibacy · the late doctrines · all 165 distinct Protestant counter-claims, then on to atheist, Orthodox, Islamic, LDS, and Jewish.

2026–2027 build roadmap

— The Source Discipline —

Every cited source is verbatim from the canonical edition: Scripture from the Greek New Testament + Hebrew Tanakh + DRA + RSV-CE; the Catechism of the Catholic Church; the ecumenical councils' definitions; the Church Fathers in Migne's Patrologia Graeca and Latina; the modern magisterial documents from vatican.va.

Apologists are removed from the citation chain. When the Sed Contra engine answers, it cites Augustine in the year he wrote the line, not the modern apologist who quoted him. The reader can verify every word against the primary source itself.

The errata page logs every correction publicly, the day it is found.