As an introduction to the Cosmological argument take a look at this PowerPoint.
Don’t forget Aquinas was a champion of the philosophy of Aristotle. You can see the more scientific approach coming through in what Aquinas says.
Remember too the importance of causation we say in Aristotle and the idea of the Prime Mover.
This argument a posteriori. Aquinas looks at the world and draws conclusions from what he sees. The difficulty with this view is when one moves beyond the world. Contingent facts are fine but do they need a necessary cause?
(One) The argument from motion
- Everything in the world is moving or changing.
- Nothing can move or change by itself.
- There cannot be an infinite regress of things changing other things.
- Therefore, there must be a first (prime) mover (changer).
- This is called God.
(Two) The argument from causation
- Everything in the world has a cause.
- Nothing is the cause of itself.
- There cannot be an infinite regress of causes.
- Therefore, there has to be a first cause to start the chain of causes.
- This first cause we call God.
(Three) The argument from contingency
- Everything in the world is contingent (can either exist or not exist).
- If things cannot exist, there must have been a time when they did not exist.
- If everything cannot exist, then there must have been a time when nothing existed.
- Things exist now so there must be something on which we all depend which bought things into existence.
- This necessary being we call God.
Objections of David Hume 1711-1776
Hume was an atheist and an empiricist so there was not chance that he might be sympathetic to Aquinas’ point of view.
1. Hume thought the argument was logical but not correct.
2.Using the evidence of Aquinas there seemed to be no reason why there simply had to be one Prime Mover or world creator, logically there could have been lots of them .
3. He challenged the idea of cause and effect. Does one thing cause another to happen or is that simply the pattern we put on a series of events.
4. He questioned why the Prime Mover of world creator had to be the God of Christianity.