The Cosmological Argument

Simply put

Premise 1
Everything seems to be caused by something else

Premise 2
a) There is a regression of causes going back infinitely
b) There is something uncaused which caused everything else

Premise 3
The chain of causes cannot go back infinitely

There must be an uncaused cause, which caused everything else to exist. This we call God.
Therefore God exists

This is an a posteriori argument
which means that it starts by looking at the world.

 Hilbert's Hotel
This thought experiment raises important questions about infinity which help to establish the truth of Premise 3.


Premise 1
  • Can we really know this? The universe is vast and we only know about a very small part of it.
  • We don't know enough about it to make this a true premise.

Premise 2

  • Both options contain problems:
  • 2a) would seem not to be true, (see Hilbert's Hotel example)
  • 2b) contradicts Premise 1!
  • For 2b) to be correct, we would have to change Premise 1 so that it said "Everything is caused by something else, except for one thing which isn't."
  • We cannot change Premise 1 like this, because the existence of the "one thing which isn't" is what the argument is trying to prove!


  • Even if we accept that there must be an uncaused cause, the argument does not prove that it is "God". The western idea says that to be God he must be omnipotent, omniscient, and omnibenevolent (all powerful, all knowing, all good) and an intelligent being. The cosmological argument proves none of these.

© Mr.B at Woodford County High School