Using philosophical arguments in an attempt to prove the existence of God has a long tradition. Not long ago, these arguments had fallen a little out of favour as non-believers thought they proved nothing and believers often felt they didn’t need to prove anything. But interest in them has grown in recent times, as christian philosophers and apologists have revived and sometimes improved them, and atheists have responded with more trenchant criticisms.
One of the strongest arguments now is the cosmological argument, strengthened by modern science and commonly used in debates by christian philosopher William Lane Craig.
The Kalam argument
This is one form of the cosmological argument, named after the Arabic name for a philosophical tradition where the argument was first developed. The argument has the following propositions:
- Whatever begins to exist has a cause external to itself.
- It is impossible for a series of events in time to have no beginning.
- Therefore the universe began to exist at some time.
- Therefore the universe has a cause.
Are the premises true?
The main discussion centres around the first two premises.
Premise 1 is an observation from our experience of the universe – if something changes, something caused it to change. It is common sense. However opponents of the argument argue that (1) what applies within the universe may not apply to the universe as a whole, and (2) quantum events are uncaused, so premise 1 cannot be always true.
The first objection doesn’t take us very far because it may equally be true that what applies within the universe may apply to the universe as a whole. The argument about the second objection centres on the definition of ’cause’. Some models of quantum physics are causal, but on the most accepted model there is no specific trigger. Nevertheless, there are clear preconditions that must be met before a quantum event can occur, i.e. necessary but incomplete causes.
Premise 2 also seems like common sense. It is impossible to count down from infinity to any number, so it must equally be impossible for the universe to have existed for an infinite time and for us to be here now. Further, if the universe had existed for an infinite time, according to the second law of Thermodynamics, every possible physical process would have occurred an infinite time ago, and the universe would be effectively dead.
It is harder to argue against this premise. Some opponents of the argument argue that infinite time is nevertheless possible (without really explaining how); others speculate about circular time. But I think it is fair to say that these objections are not very satisfactory – at best they throw only a slight doubt on the argument.
The formal argument doesn’t conclude with God, but with a cause. But consideration of the qualities of this cause (timeless, non-material, making a choice to create, etc) are suggestive of God, and I can’t think of anything else that meets the requirements.
It is clear that the main counter argument to the Kalam is quantum indeterminacy. I find this objection less than convincing for two reasons:
- A quantum event does not occur out of nothing, but requires a quantum vacuum to already exist, and this is far from ‘nothing’, for it has energy fluctuations and contains particle – anti-particle pairs. Thus it cannot be compared to the beginning of the entire physical universe, which, by definition, must have appeared out of nothing.
- I would think the first premise could be amended to Whatever non-quantum entity begins to exist has a cause external to itself. and the argument would still stand.
The objections make it impossible to consider the Kalam argument as a proof that God exists, but the common sense logic of the argument and the speculative nature of the counter arguments seem to me to make it a powerful argument that it is much more likely that God exists than that he doesn’t. But of course others conclude differently.
I have looked at the argument in more detail, including a discussion of 8 separate objections in The cosmological argument.