The Ontological Argument

Question 1

Aquinas’ First Way

Answer 1

The Argument From Motion:

• Some things are in motion or in a constant state of change, like wood burning in a fire
• Nothing can move or change by itself
• If everything was a secondary mover, there would be an infinite regress of movers
• There would be no Prime Mover and, subsequently, no movers, so this is false
• Therefore, there must be an unmoved Prime Mover which is the source of all motion and change - this we call God

Question 2

Aquinas’ Second Way

Answer 2

The Argument From Causation:

• Everything in the universe has a cause
• Nothing can be the cause of itself
• If there were an infinite regress of causes, there would be no first cause, and therefore no causes, so this is false
• Therefore, there must be a First Cause, the source of all causes - this we call God

Question 3

Aquinas’ Third Way

Answer 3

The Argument From Contingency:
First Half:
- Everything in the world in contingent
- Therefore, there must have been a time when nothing existed
- Contingent things exist now, and therefore there must be something on which we all depend which brought them into existence. and this being is God and He is necessary
Second Half:
- Every necessary thing must be either caused or uncaused
- There cannot be an infinite regress of uncaused necessary beings, as there would be no ultimate cause of necessity
- Therefore, there must be an uncaused necessary being responsible for the existence of all caused necessary being and all contingent beings
- “This all men speak of as God” - Aquinas, Summa Theologica

Question 4

Criticism From Bertrand Russell

Answer 4

• Challenged the argument in his 1948 radio debate with Copleston
• Fallacy of Composition: What is true of the parts is not necessarily true of the whole - just because what we see in the world has a cause doesn’t mean that the universe has a cause (“just because you have a mother doesn’t mean the universe has a mother” - Russell”)
• The existence of the universe is a “brute fact”, so does not need a cause or origin
• We cannot necessarily explain everything through causes - does everything have to have a cause, even the universe?
• It is only probable that most things in existence are caused, and we may not be able to apply that idea to all things. Some things in science don’t appear to have causes, e.g. individual quantum transitions in atoms

Question 5

Criticisms from Hume

Answer 5

• The universe might be a necessarily existent being - Occam’s Razor: the conclusion is most likely if it requires fewer assumptions. The universe could be necessarily existent rather than contingent upon an unseen, necessarily-existent God
• Hume argued for an infinite regress - on could argue, what caused God?
• Hume argued that nothing can be said about the nature of God as a necessarily existent being