Something from nothing
Let us start with the universe, the whole thing, the big picture. Why is there a universe? Why is there something rather than nothing? And how did all come about? These are big questions. Philosophers discuss these questions when looking at what is known as "the cosmological argument".
There are many ways of approaching the cosmological argument and many ways of stating it, but here is one common formulation:
- Everything that has a beginning has a cause.
- The universe had a beginning.
- Therefore the universe had a cause.
This is a deductive argument, so if the premises (1 and 2) are true then the conclusion (3) is true. Intuitively, I think most people would accept the first premise and nowadays almost all philosophers and scientists accept the second premise, so it seems probable that the conclusion is true.
Imagine the alternatives
A good way to think about this is to try to imagine the alternatives. If the universe did not have a cause then either it didn’t have a beginning or popped into existence from nothing. But the universe did have a beginning. Around 14 billion years ago the universe began with the Big Bang. But the other alternative doesn’t seem particularly likely either. If you can get something from nothing, why do scientists spend so much time and effort looking for causes and explanations? If universes can just pop into existence uncaused then what is there to stop a brand new universe popping into existence in my shoe, say, or in my tea. If you find it just a little bit too unbelievable that the universe just winked into existence without rhyme or reason, then it must have had a cause.
What caused the universe to exist?
The obvious follow-up question is what sort of cause are we looking for? The universe is space and time; what came into existence at the Big Bang was space and time. So whatever caused the universe to exist, whatever caused space and time to exist, must not exist in space (non-spatial) and must not exist in time (non-temporal) but – and this is the important bit – must also have cause power sufficient to kick off the Big Bang. And if you think about it, there aren’t that many options. If you are the sort of person who believes in abstract objects (i.e. that things like the number 3 aren’t just concepts but have independent existence) then you might identify abstract objects as potential candidates. After all, they are non-spatial and non-temporal. Unfortunately abstract objects don’t have causal power (the number 3 can’t cause anything). The only other available alternative seems to be an eternal and immaterial mind, and that sounds a lot like God.
"Aha!" the atheist cries, "if the universe requires a cause surely God requires a cause too." But this would be to misunderstand the argument. The universe requires a cause because it had a beginning (i.e. it is not eternal). But, God does not have a beginning (he is eternal) and so does not require a cause.
So if you can't get something from nothing (and you can't) and if the universe had a beginning (and it did) then it seems you need (some kind of) God.