Belief, uncertainty and unbelief

Arguments for the existence of God

Aristotle (384-322 BCE)

Aristotle and the Prime Mover

• All movement depends on there being a mover.

• By movement, Aristotle was referring to all change (growth, melting etc.)

• The result is a chain of events with each movement being caused by a mover.

There must be a beginning to all of this…

• The chain of events cannot continue infinitely.• This must be an eternal substance, immune to

any change (cannot decay or die).• Must be unmoved (not moved by anything

else)• Aristotle called this unmoved mover the Prime

Mover.

Aquinas (1224 – 1274)

St Thomas Aquinas

• He felt Aristotle’s logic was compatible with Christianity and often quoted him in support of his arguments about God.

• He put forward his own Cosmological argument, three different ways.

ONEMOTION

• Any kind of motion, including any change of quality or quantity.

• This chain of movements cannot go back infinitely.

• There must be a first mover which is itself unmoved.

• This Prime Mover is God.

TWOCAUSE

• Cause and effect in the world.• Nothing can be the cause of itself.• Aquinas rejects an infinite chain of

causes.• There must be a first uncaused cause.• This first cause is God.

THREECONTINGENCY

• Everything that begins to exist has a cause.• The universe began to exist.• The universe must have a cause…

• If time were infinite..• There would be a time when nothing existed…• This is because of contingency• If something is contingent it by definition

cannot continue forever…

• If there was a time when nothing existed…

• Something must have caused things to exist.

• This thing must be necessary.• This necessary being is God.• God is necessary because if God didn’t

exist then nothing else would exist.

Challenges

David Hume1711-76

Hume• We only know what we experience.• We experience cause and effect in the

world.• This leap from experienced cause and

effect to the cause of the universe is IMAGINED.

• The mind has connected the two events – induction.

• This is not evidence of God.

Immanuel Kant (1724-1804)

Kant

• The idea that everything in the world has a cause only applies to sense experience.

• This cannot apply to something we have not experienced.

• It is impossible for anyone to have knowledge of anything outside time and space.

Bertrand Russell (1872-1970)

Russell

• Fallacy of composition• This means ascribing properties of the

parts of a whole to the whole.• ‘Objects within the universe are created.

The universe is created.’