The kalam cosmological argument is, in my opinion, one of the most persuasive arguments for God's existence; it is based on the following simple syllogism:
1) Everything that begins to exist must have a cause.
2) The universe began to exist.
3) Therefore, the universe must have a cause.
It's pretty simple and logical, and the biggest point of contention is the second statement. The first one is quite obvious (although, surprisingly, some people do disagree with it), and the third one flows logically from the first two. Since the first statement is the easiest to defend, let's look at that one first.
I. The Impossibility of the Universe Having Come from Nothing
The law of causality says that an effect cannot be greater than its cause. For example, in chemistry, when equations are balanced, the number of atoms of the same type on each side of the equation must be the same. If a chemical reaction takes place with five carbon atoms, the result cannot have seven carbon atoms; you cannot end up with more than you started with. When we apply this to the universe, it's pretty easy to see how the universe could not have popped into existence from total nothingness. Since nothingness is nothing and does nothing, the effect of the universe, which is something, is greater than and cannot come from absolute nothingness. To put it in mathematical terms, you cannot get a billion (which can represent the universe) simply by staring at zero (which can represent nothingness) and hoping for something to happen.
There is, however, one scientific objection to this principle that must be answered. In his book The God Hypothesis, Michael Corey presents us with this objection.
�a series of recent developments in the field of quantum cosmology�indicate that small bubbles of mass-energy can spontaneously form by pure chance in the vacuum of space, due to the phenomenon of quantum uncertainty. While the vast majority of these bubbles will quickly pop back out of existence, it is possible for one to spontaneously inflate to a much larger size, due to the existence of another set of physical laws that promote rapid inflation. It is even conceivable that one of these bubbles could spontaneously grow into a universe that is similar to our own.1
While this may seem to totally destroy the basic premise upon which my whole argument is built, Corey responds to this objection as quickly as he presents it.
It is important to understand, though, that this sort of quantum fluctuation doesn't take place out of absolute nothingness. It takes place out of a larger quantum field that apparently underlies all of physical reality. Without this mysterious quantum field, there wouldn't be any such thing as quantum events at all.2
He's saying that in order for these quantum fluctuations to take place, there must be a larger quantum field underlying the vacuum from which these bubbles are formed. William Lane Craig puts it a bit more clearly in Theism, Atheism, and Big Bang Cosmology:
For virtual particles do not literally come into existence spontaneously out of nothing. Rather the energy locked up in a vacuum fluctuates spontaneously in such a way as to convert into evanescent particles that return almost immediately to the vacuum�The microstructure of the quantum vacuum is a sea of continually forming and dissolving particles which borrow energy from the vacuum for their brief existence. A quantum vacuum is thus far from nothing, and vacuum fluctuations do not constitute an exception to the principle that whatever begins to exist has a cause.3
Here we see Craig stating a bit more clearly the same thing that Corey said: quantum fluctuations depend on the larger quantum field for their existence, so they don't pop into existence from nothing, and they don't constitute an exception to the principle that things don't pop into existence from total nothingness.
Now that we got that small problem out of the way, let's look at the evidence in favor of the second statement.
II. The Impossibility of the Past Having Been Infinite
This is really the meat of the argument, the actual philosophy. The kalaam argument aims at demonstrating that the universe cannot be infinitely old, and therefore must have a creator.
A. The Impossibility of the Existence of an Actual Infinite
The problem with the existence of an actual infinite is that it results in several absurdities. First, let's take a simple example. The set of all integers includes the positive numbers plus the negative numbers; therefore, the set of integers must be larger than the set of positive numbers. However, since both sets are infinite, they are both equal (because infinity equals infinity). But this is absurd; one set cannot be both larger than and equal to another set at the same time. Now let's look at this example from the other side. We know that when you add more members to a set, it always gets bigger. For example, if I add one cookie to a set of four cookies, I get five cookies. Now, if I add the set of negative numbers to the set of positive numbers, I would expect to get a new set that is bigger; however, since the set of positive numbers is infinite, when I add the set of negative numbers, the new set is still infinite. The set is still the same size, but that's absurd! A set cannot gain new members but still remain the same size. Now let's try subtracting from an infinite set. We know that if you take members away from a set, it gets smaller. For example, if I have four cookies and I take away one, I'm left with three cookies. Now, if I have the set of integers and take away the negative numbers, I would expect to get a set that is smaller, but that's not the case. The remaining set, the negative numbers, is still infinite, and is therefore the same size as the original, but again that's absurd! How can a set lose members but still remain the same size? So we see that infinity minus infinity still equals infinity, right? Not always. Let's now subtract another infinite set from the set of integers. If we subtract all the numbers except for four from the set of integers, how many numbers are we left with? We are left with one number, which is a finite set. But how can this be? First we subtract infinity from infinity and get infinity, and now we subtract infinity from infinity and get one! The same equation gives us two separate answers! This is the ultimate absurdity that results with an infinite set. An infinite set would give us all of these absurdities, so therefore, no infinite set (including an infinite set of past events) can exist in physical reality.
Now, you may be sitting there thinking, "Doesn't this guy realize what he's doing? He's using an infinite set, the set of integers, to prove that an infinite set can't exist! But no matter how many absurdities he gives us, the fact that the set of integers exists and is infinite disproves his whole argument!" But here's the difference. I'm arguing against the existence of an infinite set that exists in physical reality, but numbers don't exist in physical reality. You can't point to something and say, "Look, there's two," or, "Look, there's five and a half!" Numbers are merely ideas that we have in our minds, not physical realities, so they do not represent things that actually exist in the universe. Events in time, however, are physical realities, and they do exist in the universe.
B. The Impossibility of Crossing an Actual Infinite
This second philosophical argument demonstrates that, even if an actual infinite is possible, the set of past events cannot be infinite because an actual infinite cannot be crossed; you cannot count to infinity. Since any number plus one is always finite and infinity has no immediate predecessor, it is impossible to get to infinity by successive addition, but that's exactly what time is: successive addition. If the past were infinite, an infinite series of events would have to have been completed one right after another to get to the present moment; however, we know that an infinite set cannot be formed by successive addition, so this hypothetical scenario could not have happened. Therefore, the past must be finite.
Some atheist philosophers say that this argument assumes an infinitely distant starting point from which to start counting events, but an infinite past implies no starting point, not even an infinitely distant one, and that the amount of time from any point in the past to the present is always finite (just like the number of integers from 0 to any negative number is always finite, even though the set of negative numbers goes back infinitely), so this argument is invalid. However, this misses the point. Whether or not there are points in the past that are infinitely distant from the present is irrelevant; the point is that the whole set of past events, not any one part of it, had to have been crossed to get to the present moment. If the past is infinite, then the whole set of past events that would have to be crossed would definitely be an infinite, but this is impossible. Therefore, the argument still stands.
Before we go on to the scientific argument, an objection must be answered. If the universe cannot be infinitely old, then shouldn't this limitation apply to God also? No. Since time must have had a beginning, it must also have been created by God, which means that God must be outside of it and unaffected by its laws and limitations.
III. God's Attributes
Well, we know that the universe was created, but by who or what? Can we know anything about this God? Yes, and here's what we can know.
� God must be an intelligent being. For one, the universe displays an extremely high amount of design that shows God's amazing intelligence (but I won't get into that too much because it's another argument, the teleological argument). Secondly, as I said in my essay on why we can't know everything about God, God must be self-existent. If He isn't then some other, higher being is God, and this being is self-existent. Either way, the ultimate, supreme being is self-existent, so there must be something in His essence that makes it necessary for Him to exist. His very essence must be existence. If His essence is existence, then He must perfectly embody every attribute of existence, and intelligence is an attribute of existence. In addition, not only must He have intelligence, but He must have infinite intelligence (to perfectly embody intelligence, He must know everything), which means that He must be omniscient.
� If God perfectly embodies every attribute of existence, then He must have every power, which means that He must be omnipotent.
� Since God created time, He must be outside of it.
� Since God created space and matter, He must be non-spatial and non-material, which means that he must be a spirit.
� Since the universe does not have to exist, there must be something keeping it in existence, and this something has to be God (if it's anything else, then God keeps that in existence, and, for the purposes of this attribute, we get the same result). Since God keeps everything else in existence, He must be everywhere, and He must therefore be omnipresent.
� If God perfectly embodies existence, then He must have every perfection, which means that He must be all good, or omnibenevolent.
Endnotes
1) Michael Corey, The God Hypothesis, 196.
2) Ibid., 196-197
3) William Lane Craig, "The Caused Beginning of the Universe," in William Lane Craig, Quentin Smith, Theism, Atheism, and Big Band Cosmology, 143-144.
