Knowledge of God's Existence

What are the two main ways to gain knowledge about God?

• Natural theology – knowledge of God through human reason and observation of the world.

• Revealed theology – knowledge of God through faith and divine revelation, e.g., the Bible.

What are Fideists?

• Theologians who reject natural theology.

• Argue that knowledge about God can only be gained through faith, not human reason.

• Examples: Karl Barth, Luther in certain contexts.

What is Aquinas’ main argument for natural theology?

• Reason is a God-given gift (humans made imago Dei).

• Reason can detect:

  • God’s existence (Cosmological & Teleological arguments).

  • God’s morality (via Natural Law ethics).

• Humans retain reasoning ability despite original sin; distinguishes us from animals (who cannot sin).

How does Brunner develop Aquinas’ idea?

• Original sin destroyed the material image (perfect relationship with God) but not the formal image (reason, language, moral responsibility).

• Humans retain capacities distinguishing them from animals → reason still functions.

Counter: Karl Barth on natural theology?

• Reason is unreliable due to corruption from original sin.

• “The finite has no capacity for the infinite.”

• Danger of idolatry if humans try to know God via reason → e.g., nations or ideologies.

• God should only be known through faith and the Bible.

Evaluation of Aquinas vs Barth?

• Barth misrepresents Aquinas (straw man). Aquinas doesn’t claim we can fully understand God, only infer a higher power.

• Reason can sometimes work under God’s grace.

• Natural theology provides inductive evidence, supports faith rather than replaces it.

What is Calvin’s sensus divinitatis?

• Humans have an innate ability to sense God.

• Natural theology through sensing God, not reasoning.

• Explains why even remote tribes have some sense of a higher power.

• Helps justify moral accountability: people are without excuse for not believing in God.

How does Plantinga interpret Calvin?

• Humans have a disposition or tendency to believe in God.

• Triggered by experience of the world (“nature as a mirror”).

• Not literal knowledge from birth; requires experience.

Limitations & criticisms of Calvin?

• Modern atheism suggests this sense may not exist (e.g., China 90% non-religious).

• Social pressures in Calvin’s time may have influenced his view.

• Plantinga: sin may interfere with God-sense (noetic effect) → weak as atheistic societies often have low crime.

What does Romans 1:20 suggest?

• God’s invisible qualities can be understood from creation.

• Supports Aquinas’ style of natural theology: inductive reasoning about God’s power, knowledge, and nature from the natural world.

Calvin’s interpretation vs Aquinas’?

• Calvin: Romans 1:20 supports sensing God, not reasoning.

• Aquinas: implies reasoned understanding from creation (use of “understood” suggests reasoning, not just feeling).

Barth’s reinterpretation?

• Sinful human minds are too corrupt to know God via creation.

• Only revelation through the Bible is reliable.

Evaluation of Romans 1:20 interpretations?

• Aquinas’ reading stronger: text implies humans can understand God’s qualities from creation → reasoned inference.

• Barth’s claim less convincing → verse stresses “without excuse”, implying God intended knowledge through creation.

Augustine on original sin?

• Explains the existence of evil in the world.

• Humans inherit sin from Adam and Eve → innate moral corruption.

• Influential for Protestants (Calvin, Barth).

Aquinas’ reconciliation of natural theology & original sin?

• Humans retain reasoning ability despite original sin.

• Corruption is real, but we are not reduced to animal level.

Pelagius’ approach?

• Denies original sin.

• Sin explained by social conditioning, upbringing, and culture, not inherited nature.

Modern scientific criticisms of Augustine?

• Evolution: the Fall is fictional; humanity did not descend from two people.

• Lamarckian inheritance (sin passed biologically) is discredited.

Defences of original sin?

• Niebuhr: observable human evil confirms original sin (Nazism, atrocities).

• Chesterton: human sin visible “in the street”.

Counter-evaluation from modern evidence?

• Stephen Pinker: global violence and crime rates have declined.

• Social progress contradicts the notion of irresistible sin.

• Morality better explained by social conditioning and culture (Pelagius).

Freud & Pelagius on human nature?

• Freud: rebellion against social norms explains “sin”.

• Pelagius: cultural environment shapes behaviour; humans are not inherently sinful.

• Evolution provides a natural explanation for selfishness and aggression.

Natural theology

God known via reason (Aquinas) or innate sense (Calvin).

Revealed theology

Faith/Bible is necessary for full knowledge (all agree).

Original Sin

Augustine explains evil, but modern evidence challenges inheritance.

Barth

rejects human reason; relies solely on revelation.

Romans 1:20

supports reasoning about creation → Aquinas stronger reading.

Pelagius & modern science

social/cultural factors can explain immorality.