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Monday, March 26, 2012

First Cause: Part I

In my experience, the so-called “Argument from First Cause” (henceforth the AFC) is the most popular “justification” for belief in a God.  As one of my friends put it, he finds it absurd to believe that the whole universe exists “just because.”  Unfortunately he never did answer me when I asked whether he wanted an explanation for the universe’s causal history, or an explanation of its purpose. 

As one might expect, the AFC concerns itself with the universe’s causal history.  Fortunately, I’m a physicist (well, a grad student, but close enough).  Unfortunately, I’m not an early-universe cosmologist.  But doubly-fortunately, you don’t have to be a physicist or an early-universe cosmologist to understand most of the errors with the AFC.  So let’s start with the AFC itself.  There are of course many ways the argument has been presented over the years, but most of them go something like this:

Premise 1: Everything that begins to exist must have a cause

Premise 2: The universe cannot have an infinite past (sometimes this is separately argued)

Lemma 1: Because the universe cannot have an infinite past, it must have begun to exist

Conclusion: Thus the universe must have an uncaused first cause, and we call this cause God.

Now there are actually an enormous number of errors being made in this argument.  The one most atheists tend to point out is that the insertion of God as the cause of the universe doesn’t help the question of first cause because we can ask “Well what caused God?”

Now theists have gotten clever and chosen the crafty little phrasing shown above for premise 1.  They then say that God didn’t “begin to exist” because he’s eternal, and thus there’s no need for a cause.  Some atheists call this special pleading, but I prefer to say that it flies in the face of premise 2.  Why can God have an infinite past but the universe can’t?

There are a couple of ways premise 2 tends to be supported.  The first is by a completely ridiculous argument involving the process of counting and the claim that it is impossible to traverse an infinite series.  This argument fails for several reasons.  First, counting is a process which has a beginning, so it is silly to try and use it to understand something which has no beginning.  Second, the same argument applies just as well to God, which leads us back to the “What caused God?” problem the theists are so keen to avoid.  Thirdly, it is entirely possible to traverse an infinite series.  We do it all the time… literally.  Every second that passes contains an infinite (and in fact uncountable) number of “moments,” or points in time.  This is, in fact, a point that philosophers have often woefully misrepresented.  They will present some iterative sequence, say halving a distance, and argue that since no number of iterations completes the task, the task will never be completed.  What they miss is the equivocation between “never no matter how many iterations” and “never no matter how much time.”  Though in the counting argument against an infinitely old universe, the equivocation is between “never no matter what finite amount of time passes” and “never no matter what infinite amount of time passes.”  It seems obvious to me (and I suspect it is obvious to most mathematicians) that if you count one number per second for an infinite number of seconds, then you will have counted an infinite number of numbers.  Unfortunately, this idea seems to have escaped many philosophers.

The second way in which a finitely old universe is argued is much more sensible.  Basically, the theists will point to the big bang and say “Look, finitely old universe.”  This is much better than the silly counting shenanigans some theists try to use.  However, there are still a few subtle issues that come in to play even after one accepts that there was no universe before the big bang.  Unfortunately, these problems require a bit of mathematical and physical knowhow.  Some of the physics challenges premise 1 directly, while the rest joins the math in challenging whether the universe genuinely began to exist.  However, because the concepts needed to understand these problems will require some explanation, I’m going to postpone their discussion until next week.

But there is still one more gaping hole in the AFC, and it doesn’t require math or physics to notice them.  In fact, the hole is exactly the kind of thing I cautioned against very early on in this blog.  You can redefine your terminology if you wish, so long as you are careful of two things.  First, you have to tell your reader what you’re doing.  And second, you have to be very careful not to sneak in unwarranted connotations.

Now let’s say we accept both the premises, from which the lemma and the conclusion follow.  But what exactly is the conclusion?  The conclusion is that there exists some uncaused first cause.  Now the theist decides to use the word “God” to refer to this cause, which is perfectly fine at first.  I’m okay admitting that there’s a first cause.  And I guess I’d complain about calling it “God” because it’s a loaded word and you’re also insisting on some weird capitalization rules, but nothing technically incorrect… until you tell me to worship it.

And now we can see where the argument has gone truly awry.  Even if the premises are granted, and the argument is valid, what is actually shown is that some uncaused first cause exists.  Absolutely nothing is given to demonstrate that this cause is sentient, deserves worship, had a son, loves humans, lives in a utopia, wields great power, tends to be just and benevolent, or anything of the sort.  In fact, the AFC isn’t actually an argument for anything theists generally mean when they say “God.”  Rather than actually trying to argue for the existence of a powerful, benevolent being who listens to prayers and wants your worship, the AFC uses the word “God” to sneak all that in.

And this is actually one of the biggest problems I have with most arguments from theists.  They’ll argue (or often simply assert) that there must be something out there beyond what science has discovered.  But this is actually quite obvious to most scientists.  The problem is when the theists use the word “God” to hide the transition from something to someone.  If you want to demonstrate that your god exists, you can’t just tell me that something is out there.  You have to do more than that.  You have to show the something exists, and then you have to show that it has all those properties you insist your god possesses, like sentience and benevolence.  But what most theists end up doing is just calling the thing “God” and then acting as if they had already shown that all the connotations applied, even though they never did any such thing!

So remember, even if we except that the universe must have had some uncaused first cause (and I actually do think this is a likely fact), this does nothing to demonstrate the existence of a loving and powerful and sentient agent who wants you to worship him.  Don’t get fooled by the silly word play.  When a theist uses the word “God” to hide the fact that they don’t actually have an argument, call them on it.


  1. Interesting. I've never actually heard the counting part of the argument Zaq. Usually I see the AFC formalized as:

    Premise 1: All events have a cause.
    Premise 2: An infinite series of cause and effect is impossible.
    Lemma 1: Therefore, the universe must have a cause.
    Conclusion: That cause would be the first cause, and we call it God.

    I usually refute this slightly differently than you have. I point out that premise 1 is not true (citing atomic decay or subatomic particles popping into and out of existence as an example of uncaused events). Premise 2 is not vindicated (a serial universe could be possible, as could an infinite number of universes branching off one another). Lemma 1 only follows if the first 2 premises are sound (they aren't), and its not even clear if we can talk about a 'cause' of the universe in a meaningful way because we have trouble defining non-temporal cause and effect. Finally, the conclusion commits both the special pleading fallacy you noted, and jumps from "The universe had some cause" to "The universe has an uncaused cause that has the properties of my god (agency, omnipotence, benevolence, etc.)."

  2. Great piece here, looking forward to part 2!

    I readily admit I have but a layman's understanding of any sort of physics, but does Plank time present some issues for the idea of there being an infinite number of moments within a given period of time?

  3. @Kent: I'm delaying the physics and math stuff until next post because it's more technical.

    @Anonymous: Plank time is just a unit of time created from combining fundamental constants. It might represent some lower bound on temporal divisibility, but it might not. The problem is that we don't yet have a well-supported theory of quantum gravity, so we don't know what will happen when we quantize spacetime.