Faith and reason
Learn to explain the faith with reason, in the tradition of Thomas Aquinas.
The Catholic faith is not opposed to reason. The Church teaches that we can know God exists by the natural light of reason, and Thomas Aquinas showed how philosophy helps us understand what we believe.
Here you learn the basics of that tradition step by step, so that you can explain the faith and answer common objections. The path leads from God and man, through God's covenants and Jesus Christ, to the Church and the life of grace. Each module builds on the one before, and the concepts are explained where they are first needed.
The name comes from John Paul II's encyclical Fides et ratio (1998), which compares faith and reason to two wings that raise us towards the truth.
God and man
Does God exist, and who am I?
What reason can know about God and about man.
- Why is there anything at all?Why nothing can give itself its own existence. Thomas's argument from essence and existence.
- Everything that changesThomas's first way, built on act and potency: why all change in the end needs something that does not itself change.
- What could fail to existThomas's third way: why a world of things that come and go needs something that exists of necessity.
- Why only one God?Why God is simple, infinite and good, and how we can speak of him without making him one being among others.
- Faith and scienceWhy the big bang and evolution do not make God redundant, and where science and faith meet.
- Body and soulWhat a human being is: why the soul is the form of the body and not a spirit living in it, and what that means for freedom.
- Why is there evil?The most common objection to the existence of God, and what the Church means by the Fall and original sin.
God seeks man
Has God spoken?
How God has made himself known, and how he prepared his people.
- Can God speak to us?Coming later
What revelation is, and why faith does not mean you stop thinking.
- The covenantsComing later
Abraham, Moses and David: how God bound himself to a people and what his law gave it.
- The prophets and the hope of the MessiahComing later
What the prophets promised, and what the people expected of the Messiah.
Jesus Christ
Who is Jesus, and what does he fulfil?
The Christian claim: that God became man.
- Who was Jesus?Coming later
What historical sources say about him.
- Who do you say that I am?Coming later
What Jesus said about himself, and why he cannot be seen as just a good teacher.
- God and manComing later
The Incarnation, one person in two natures as the Council of Chalcedon taught in 451, and the Trinity.
- Why the cross?Coming later
How the death of Jesus can save, and what it has to do with sin.
- Did Jesus rise from the dead?Coming later
The empty tomb, the witnesses and the disciples who were ready to die for what they had seen.
The Church
How does Christ continue his work?
Why Christ wanted a Church, and what it teaches.
- Did Jesus found a Church?Coming later
Peter, the apostles and their successors.
- Who decided what belongs in the Bible?Coming later
How the books of the Bible were gathered, and how Scripture and Tradition belong together.
- MaryComing later
What the Church teaches about the mother of Jesus, and why Catholics pray to her, not least in the rosary.
- Death and what comes afterComing later
Judgement, purgatory, heaven and hell, and the Christian hope.
Living in grace
How does one live as a Christian?
The sacraments, conscience and prayer.
- Why sacraments?Coming later
How visible signs can give invisible grace, explained with form and matter.
- The EucharistComing later
What transubstantiation means, explained with substance and accident, and why the Mass is a sacrifice.
- Why confess to a priest?Coming later
What confession is, and why you don't just ask God for forgiveness on your own.
- The natural law and conscienceComing later
Why good and evil are not just a matter of taste.
- PrayerComing later
What prayer is, and how the rosary helps you pray with Mary.
Conversations
How do I answer when someone asks?
Maps for particular conversations, with answers and sources.