How strong is the Kalam Cosmological argument?

May 2nd, 2018 in clues. Tags: , , , , ,

A friend and I have been discussing the Kalam Cosmological argument recently, so I thought it might be worth posting about it.

The Kalam argument has been used many times by philosopher William Lane Craig in public debates, with some success. His use of the argument is itself much debated on the internet. I have summarised the argument and its main objections in The Cosmological argument, which I have recently updated.

The Kalam argument

In its simplest form, the Kalam argument is as follows:

  1. Whatever begins to exist has a cause.
  2. The universe began to exist.
  3. Therefore the universe has a cause.

The Kalam argument on the internet

My friend and I were discussing things people on the internet say about the Kalam argument, and whether the comments are justified. Five different comments are worth discussing.

Quantum physics and causes (premise 1)

Common sense tells us that when something new happens, something else caused it. But common sense doesn’t always seem to apply to quantum physics. So, the physicists tell us, quantum events can occur randomly at any time without a cause, and these events can include a particle coming into existence.

I am not a theoretical physicist, so I checked out those who are, and found it isn’t quite this simple. There are many different interpretations in quantum physics, and the majority of them, including the most popular Copenhagen interpretation, include the possibility of uncaused events, but some interpretations do not.

But in all interpretations, a particle doesn’t come into existence out of nothing. For any quantum event to occur, there needs to be a quantum field, and the particle is an excitation of that field. So while the excitation may not have any cause, the particle certainly didn’t come from nothing.

So it seems we could clarify premise 1 by adding the phrase in italics:

1. Whatever begins to exist has a cause external to itself or arises out of something external to itself.

I think this premise satisfies the quantum requirements, clearly applies to our everyday experience, and so can be considered to be very likely true.

Did the universe begin to exist (premise 2)?

This has been one of the biggest arguments against the Kalam. If the universe is infinitely old (i.e. it has always been there), or if we can play games with time (as physicists say we can) so that it goes backwards, or is cyclic or something else, then we may be able to say that the universe never had a beginning.

A number of mathematical and philosophical arguments have been developed to resolve this question, but it seems that the theoretical physicists may have the last word, and we are fortunate to have theoretical physicist Aron Wall address this very topic.

Aron has reviewed the relevant physics, and says there are 7 different aspects of physics that are relevant to this question. It turns out that 5 of these point to the universe having a beginning, 1 suggests it did not, and one could be interpreted either way. He concludes:

We don’t know for sure whether the Universe began, but to the extent that our present-day knowledge is an indicator, it probably did.

So it seems that premise 2 is also probably true.

The Kalam doesn’t “prove” God, only a cause

This is clearly true. If we regard the Kalam as successful, we have only reached the conclusion that “the universe has a cause or arose out of something external to itself”.

But if the argument is successful, we have also established that this cause is non-physical (i.e. it is outside the universe). Now we can reasonably ask, what entities fit this description?

It seems apparent that it must be something we may term “supernatural”, something that is at the very least “godlike”.

And that is all the Kalam aims to do. It aims to go part way towards showing that God probably exists. Other evidence and arguments are required to show that the God of theism was the creator.

Two non-arguments

It is surprising how often statements are made on the internet that have no basis in evidence or reasoning. (Well maybe it isn’t so surprising, but it is a pity!)

The Kalam has been refuted?

People who are not themselves philosophers seem to claim this a lot. But really, no one person can claim this by themselves, even if they feel they have come up with a killer argument. It will be the verdict of the philosophical community, and the wider apologetics community, that decides if the Kalam is refuted.

If the argument is truly refuted, it will cease to be of much interest. Philosophers will move on to other challenges. But as far as I can see, the argument has neither been refuted nor proven. It remains under discussion, with different facts and arguments being assessed and discussed.

So we each may conclude that the argument is, in our own minds, more or less probably true or false, but that is as far as anyone can reasonably say at this time. As the man in black says in The Princess Bride, “Anyone who says otherwise is selling something.”

William Lane Craig is …. (fill in the blank)

WL Craig is a philospher who has specialised in analysing the Kalam in academic papers, and then using the argument in public debates. That seems to make him a target for many who disagree with him.

You’ll hear him accused of being dishonest or simply insulted as being devious. Some claim his arguments are clearly wrong, and they can’t understand how he gets away with them in debates.

Such ad hominems are hardly worth mentioning, except they are so common. And we can, and should, immediately discount them, for two reasons:

  • Most of his debate opponents are competent and intelligent academics, who have had plenty of time to prepare against the arguments that Craig commonly uses, including the Kalam. If they are not able to easily refute him, perhaps his arguments are better than his internet critics say.
  • Such ad hominems are logical fallacies. If the arguments are so weak, simply demonstrate the weakness.

So how strong is the Kalam?

On the basis of all the above, I would sum up the Kalam as follows:

  1. In all our experience, whatever begins to exist very likely has a cause or arises out of something external to itself.
  2. The universe probably began to exist.
  3. Therefore it is more likely than not that the universe has a cause or arose out of something external to itself (see note 1).
  4. God, or something “godlike” seems to be the only plausible identification of that cause or external “something”.

That is as much as I would want such an argument to achieve, so I think it is a successful argument. And there are other forms of the Cosmological argument that overcome some of the Kalam’s weaknesses – see The Cosmological argument.

The Kalam is a long way from “proving” that God exists, but when combined with other theistic arguments and evidence, I believe it adds to the probability that God does exist.

Note 1:

It would be stretching things to estimate probabilities for the premises and conclusion, but if we give them notional probabilities to illustrate, we might have premise 1 is “very likely” = 0.9, premise 2 is “probably” = 0.8 (which corresponds with Aron Wall’s 5.5 out of 7 aspects indicating a beginning), then we end up with the probability of the conclusion as about 0.7, for which “more likely than not” seems to be a reasonable description.

Image: The Helix nebula, courtesy of NASA