St. Thomas Aquinas realised that the existence of the universe is not explicable without references and factors outside itself. It cannot be self causing since it is contingent and only the existence of a first, necessary cause and mover explains that existence of the universe.
Aquinas put forward in his book ‘Summa Theologica’ ‘five ways’ in which he attempted to prove the existence of God a posteriori. The first three ways make up the Cosmological argument.
Aquinas’ cosmological argument
(i) 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
(ii) The argument from causation
1. Everything in the world has a cause.
2. Nothing is the cause of itself.
3. There cannot be an infinite regress of causes.
4. Therefore, there has to be a first cause to start the chain of causes.
5. This first cause we call God.
(iii) The argument from contingency
1. Everything in the world is contingent (can either exist or not exist).
2. If things can not exist, there must have been a time when they did not exist.
3. If everything can not exist, then there must have been a time when nothing existed.
4. Things exist now so there must be something on which we all depend which bought things into existence.
5. This necessary being we call God.
Frederick Copleston’s reformulation of the cosmolo
Copleston reformulated the argument by concentrating on contingency. He proposed this argument on a radio debate in 1947
There are things in the universe which are contingent, they might have not existed. E.g. you would have not existed if your parents had not met.
All things in the world are like this, nothing in the world is self-explanatory, and everything depends on something else for its existence.
Therefore, there must be a cause of everything in the universe which is outside of it
This cause must be a self-explanatory being i.e. one which contains within itself the reason for its own existence – a necessary being
This necessary being is God.
Copleston and Russell’s BBC radio debate
In 1947 Copleston and Bertrand Russell had a famous radio debate, where Copleston proposed his argument.
Russell refused to accept the terminology that Copleston was using – he refused to accept the notion of a necessary being (beings that cannot be thought not to exist).
He replied “…what I am saying is that the concept of cause is not applicable to the total.” Just because each human has a mother does not mean that the whole human race has a mother. He thought that the universe was just a brute fact and needed no explanation for its existence – “I should say that the universe is just there, and that’s all.
In criticism Copleston added “… If one refuses to sit at the chess board and make a move, one cannot, of course, be checkmated.”
David Hume’s criticism
He said that we have no experience of universes being made, and so we cannot speak meaningfully about the creation of the universe. To move from ‘everything we observe has a cause’ to ‘the universe has a cause’ is too big a leap in logic. This is the same as saying that because all humans have a mother, the whole human race has a mother.