Wednesday, June 5, 2013

Philosophy of Religion, Part 3: Craig's Kalam Cosmological Argument

Readings: "The Existence of God and the Beginning of the Universe" by William Lane Craig, and a brief selection from J. L. Mackie's book The Miracle of Theism.

I imagine that anyone reading this has already encountered the famous Kalam cosmological argument, which goes like this:
  1. Everything which begins to exist has a cause
  2. The universe began to exist
  3. Therefore, the universe has a cause
You'll notice that nowhere in the argument does it say "therefore, God exists." A person might see this argument out of context and never suspect that it's trying to support theism. This is perhaps the argument's greatest weakness - it proves nothing about God on its own (why can't the cause of the universe be something else - maybe a physical starting point that we can't perceive, or something incomprehensible?). Instead, as reported by a (theistic) classmate of mine, not even Craig thinks of this as a standalone argument for the existence of God. Rather, it is meant to be one piece of evidence in a cumulative case for the existence of God. If the universe does not have a cause, then certainly God does not exist. But if the universe does have a cause, then a creator is at least one possibility, one which must be justified by further means. At the very end of his article, Craig offers a brief supplemental argument that the cause of the universe must be personal. He writes:
"In fact, I think that it can be plausibly argued that the cause of the universe must be a personal Creator. For how else could a temporal effect arise from an eternal cause? If the cause were simply a mechanically operating set of necessary and sufficient conditions existing from eternity, then why would not the effect also exist from eternity?"

This is, in fact, what I was attempting to get at in the second half of my last post (Philosophy of Religion, Part 2). I maintain the argument against a personal creator that I put forward in part 2, so I will not repeat it here. But if there is no personal creator, then, as Dr. Craig says above, why should not the universe exist from eternity? This is one of the reasons I like the B-theory of time, which states that the past and the future both exist "eternally," and that the passage of time only emerges from our perspective as creatures within this eternal structure. In fact, if the B-theory of time is true, then neither premise of the Kalam cosmological argument makes any sense, and the argument fails immediately. Craig does not address this fact in his essay.

I am told by my classmate that the B-theory of time is "fraught with problems," although I am not sure what those problems could be. It also might be possible to adapt the Kalam cosmological argument to apply even when the B-theory holds, i.e., an argument like
  1. Everything which is contingent has a necessary cause
  2. The universe is contingent
  3. Therefore, the universe has a necessary cause
This reformulation avoids the B-theory objections. Is the universe contingent? (Only existing in some logically possible worlds?) One could make a compelling case that this is in fact so. But then, what is the nature of the necessary cause? Is it God? Or a platonic form of mathematics? Or something else entirely? Craig would object that mathematical forms "cannot stand in causal relations"; I see his point, but I would dispute his line of thought. What if some version of the Mathematical Universe Hypothesis is true? (As a side note, I really like the mathematical universe hypothesis. It immediately explains fine-tuning, the existence and orderliness of the universe, and the apparent contingency of the universe. There are theoretical problems with MUH, such as the existence of so many universes that we should expect to find ourselves in any one of them but this one - but the benefits of the hypothesis are incredible, and the objections might be answerable. I'll have to look further into this.)

Let's loop back to the original argument to make some more comments. Craig spends the bulk of the essay justifying premise (2), that the universe began to exist. The scientific evidence here is decisive and uncontroversial - yes, the big bang happened. But someone might object that the universe is part of an infinite series of expanding and contracting universes. This is implausible, given our current theories of physics. However, Dr. Craig wishes to sweep away any and all similar objections that appeal to a past temporal infinity by proving, in a logical argument, that actual infinities cannot exist. It goes like this:
  1. Actual infinities cannot exist
  2. An infinite temporal regress is an actual infinite
  3. Therefore, an infinite temporal regress cannot exist
The justification of premise (1) is that if we had a collection of things which was actually infinite (meaning, in a crude sense, "infinite all at once," as opposed to a potential infinite, like counting to infinity, which is unbounded but never infinite at any particular point), then "metaphysical absurdities" would arise. Namely, if actual infinities can exist, then Hilbert's Hotel can exist, and Hilbert's hotel is absurd - so actual infinities must not exist. Really, the only argument that Dr. Craig can make here is that such a thing as Hilbert's hotel is strongly counterintuitive as a description of physical things - but why should that mean that such a thing cannot exist?

Although I am skeptical of Dr. Craig's criticism of actual infinity, I still agree that a past temporal infinity is absurd. Craig makes a second argument to this effect:
  1. A collection formed by successive addition cannot be actually infinite
  2. The temporal series of past events is a collection formed by successive addition
  3. Therefore, the past is not an actual infinite
I don't see any problems with this argument after Craig's further justification (though it presumes the A-theory of time).

Finally, one might impeach premise (1), that everything which begins to exist has a cause. This is certainly true within the universe, but why should it be true for the universe itself? Craig takes premise (1) as completely obvious, and I think I do too. If something can come into existence uncaused, then why can't anything and everything do so? Why don't we see objects popping into existence uncaused? So I think I agree with Dr. Craig on this premise.


  1. The question of "actual infinities" doesn't really seem to be sufficient to judge the concept of infinite regress. Regression is mathematical, it is temporal, but it is not itself a physical entity. The hotel cannot exist because the universe itself is, while very large, quite finite in what it contains. But that is matter, that is not time. We can experimentally suggest that time had a "beginning" per se, but we cannot rule it out based merely on the idea that there is also a limit to how much of other "physical" quantities there are.

    So even if (1) is true, (2) does not follow IMO.

    The subsequent argument is similarly flawed. (1) is in no way justified; the concept of "actual infinite" in this case is quite obscure too. How does an ordered set of events require "actual" of anything? There needs to be a much more rigorous discussion on the requirements of the simple passage of time on finite quantities in the universe, which Craig is certainly not qualified to comment on in the slightest. Again, we're talking about something that does NOT follow our intuitive understanding of "objects" - time.

  2. "There needs to be a much more rigorous discussion on the requirements of the simple passage of time on finite quantities in the universe, which Craig is certainly not qualified to comment on in the slightest."

    There certainly does need to be a more rigorous discussion, which Craig provides elsewhere and which I could not do justice to in this post. I wouldn't say he's not qualified - a major part of his philosophical career was spent studying the nature of time. I've only outlined his arguments above. He spends a great deal more time defending them and answering objections in the essay.