I watched the debate Sean Carroll and William Lane Craig held on Friday, February 21, 2014 on the topic of god and cosmology. I thought it was a good one and I will spend a few posts exploring some of the issues for the benefit of those people without a physics background who may have been a little fogged by some of the technical issues that came up.
My overall impression was that I felt that Carroll achieved what he set out to achieve, which was to show that naturalism was sufficient to understand the universe and hence preferable to the theistic approach because bringing in a god was not only superfluous but added a layer of complication that caused more problems than it solved.
You can see the full debate below. Commenter Sam Johnson has provided a link to another video where the breaks have been edited out but since I took notes of times according to the original, I will stick with that in making my points
The format was for each person to alternately speak in chunks of 20 minutes, 12 minutes, and 8 minutes, for a total of 80 minutes. That was followed by about 30 minutes of questions from the audience. The whole tone of the event was low-key and respectful. Craig went first as he always insists on doing. This is because in standard college or high school debate contests if you get to take the affirmative position, then you can frame the question in a manner that is most suitable to you and put the onus on the responder to show that your position is untenable. If the responder cannot do that, the affirmative position ‘wins’.
Carroll was urged to not let Craig go first but he did not do so, rightly taking the view that this was not a college debate contest that required him to ‘win’ according to some set of rules but a way to get the audience to compare two world views. In such a scenario, it is actually better to have the last word so that audiences leave with your views dominant in their minds. He used that opportunity excellently at the very end, as I will discuss later.
There were opening introductions and the like that you can skip, and begin with Craig’s opening statement at the 24 minute mark. As expected, Craig made two arguments for his god: the Kalam cosmological argument and the teleological fine-tuning argument. To his credit, Craig is a clear and polished speaker, so that it is not hard to follow his reasoning. But this also works against him in that the flaws become more easily apparent.
Craig began by laying out what he was seeking to achieve.
“The evidence of contemporary cosmology actually renders god’s existence considerably more probable than it would have been without it. This is not to make some sort of naïve claim that contemporary cosmology proves the existence of god. There is no god of the gaps reasoning here. Rather I am saying that contemporary cosmology provides significant evidence in support of premises in philosophical arguments for conclusions having theological significance.”
Note that Craig made the standard debating move when you are arguing the affirmative, which is to frame the question in such a way so that you are asserting the absolute minimum so that it makes countering your case more difficult. Providing “significant evidence in support of premises in philosophical arguments for conclusions having theological significance” is a pretty weak statement.
He then introduces the Kalam argument at the 26:30 mark, saying that it consists of three pieces:
1. If the universe began to exist, then there is a transcendent cause which brought the universe into existence.
2. The universe began to exist
3. Therefore there is a transcendent cause which brought the universe into existence.
He then made the (to me) astounding statement that “I take it that (1) is obviously true” and did not try to substantiate it at all, and proceeded to spend considerable time looking at cosmological arguments that he claims support (2). I thought that this was a serious mistake on his part because (1) is not at all self-evident and he laid himself open to a challenge that undermined his entire case.
To make his case for (2), he selected those papers in the literature that argued against an infinitely existing universe (or ‘past eternal’ is the language of the cognoscenti), focusing especially the Borde-Guth-Vilenkin paper, that purport to argue for a finite time for the universe, and on the implications of the Second Law of Thermodynamics. He then infers (3).
He spends the last five minutes of his talk (beginning at 39:40) on the teleological argument which he frames as follows:
1. The fine-tuning of the universe is due to either physical necessity, chance, or design
2. It is not due to physical necessity or chance.
3. Therefore, it is due to design
He argues against necessity by saying that there are an enormous number of universes (of the order of 10500) that are consistent with the laws of physics, and hence ours did not have to occur. He frames the chance argument as one in which since we exist as observers of the universe, then of course we could exist only in a universe that is conducive to us existing.
He argues against an eternal universe by saying that according to the Second Law of Thermodynamics (according to which in a closed system entropy always increases until thermal equilibrium is reached) if the universe is ‘past eternal’ then we should have reached thermal equilibrium and become effectively dead and hence the only way we could exist now is as a random fluctuation that brought the present universe into existence. But if that were the case, he says, observers like us are not the most likely outcome and that ‘Boltzmann brains’ are far more likely to emerge as observers of the universe than ‘ordinary’ observers like us. I was a bit surprised at the major role that Boltzmann brains played in this debate and will come back to it in a later post.
Next in this series: Sean Carroll’s response