COSMOLOGICAL ARGUMENTS FOR THE EXISTENCE OF GOD - AQUINAS

Inductive argument

  • Inductive arguments are probabilistic (the truth of its conclusions cannot be guaranteed by the truth of its premises)

Does everything have a cause?

  • 'We do not have knowledge of a thing until we have grasped its why, that is so say, its cause'- Aristotle

Empirical argument

  • It is all about observation/working with experience and making conclusions based on this observation
  • We cannot claim to understand something until we know its cause e.g. the universe

Aquinas' Five Ways for proving the existence of God - Book = Summa Theologica

1 - Motion (unmoved mover)
2 - Causation (uncaused cause)
3 - Necessity
4 - Perfection
5 - Design

Third Way - Contingency + Necessity

  • A posteriori
  • Inductive
  • Based in observation (empiricism)
  • Way 3 is the observation that all things we see in the universe are contingent
  • This means they are moved, changed and caused
  • They do not need to exist but they do
  • This applies to galaxies, stars, planets, people and trees
  • From the observation (all things are contingent), Aquinas concluded that SOMETHING must exist necessarily
  • It must be outside the observable universe because there is nothing in what we observe that can explain why contingent things exist
  • He therefore deduces that this external reason must be necessary

Aquinas - Summa Theologica

  • 'The third way is taken from possibility and necessity'
  • It is possible to imagine yourself not existing - e.g. if your parents hadn't of met at a certain place/time then falling in love
  • The point here, is that you can imagine these things to exist + not to exist
  • E.g. a tree - it didn't have to grow there but it did
  • These things have been created + they can change overtime
  • E.g. decay, age, rot
  • This shows it is a contingent being because it is subject to change
  • He does say that there was a time where everything didn't exist
  • If there was a time where there was nothing, how did there end up being something?
  • 'Nothing can come from nothing' - Aristotle said, Aquinas then agreed
  • If there was a point where there was originally nothing, surely there would still be nothing? - Aquinas' views this as absurd
  • There must therefore be something that necessarily being that has not been given its existence, but instead is the cause of everything else/this uncaused cause/mover
  • 'all me speak of as God' = this necessary being must be God

Aquinas Third Way

P1 - Everything in the natural world is contingent - everything can exist, or not exist

P2 - If everything is contingent, then at some time there was nothing, because there must've been a time before anything had begun to exist

P3 - If there was once nothing, then nothing could've come from nothing

C - Therefore, something must exist necessarily, otherwise nothing would now exist, which is false

P4 - Everything necessary must either be caused or uncaused

P5 - But the series of necessary beings cannot be infinite or there would be no explanation of that series

C2 - Therefore, there must be some uncaused being which exists of its own necessity

C3 - By this we all understand God