This is part 3 of a four-part series on the medieval arguments for the existence of God. Part 1 outlined the four types of arguments for God’s existence, Part 2 covered the ontological arguments, and this post (part 3) will cover cosmological arguments. Part 4 will wrap up the series by covering teleological arguments.
Cosmological arguments for the existence of God have a deep and rich history, from Plato to St. Thomas Aquinas to present day variations. The purpose of this post is not, however, to present this history in detail; rather, it is to present the argument in its strongest form to see whether or not it gives us sufficient reason to believe in the existence of God.
While the cosmological argument was originally developed by Aquinas and medieval Islamic theologians, the argument has been updated to a more concise and modern form—known as the Kalam cosmological argument—popularized by the analytic philosopher and Christian theologian William Lane Craig. In my estimation, this is the strongest form of the argument and is the variant we will consider in this post.
Keep in mind that this post does not, and could not, cover in its entirety the rich philosophical literature on this topic. What follows is simply my personal take on the subject, including what I believe to be the most salient points to consider.
First things first: did the universe have a beginning?
At the heart of the cosmological argument is the following question: Did the universe have a beginning? The cosmological argument asserts that the universe requires a first cause, but if the universe has always existed, then it obviously requires no cause. So, did the universe at some point begin to exist, or not?
First, I should point out that, to my mind, Big Bang cosmology is not necessarily relevant here, considering that there is no scientific consensus on what, if anything, caused the Big Bang, or what came before the Big Bang, or what exactly the universe, if it is expanding, is expanding into. We don’t even know if the observable universe is the only universe, or if there are multiple universes or even parallel universes and dimensions. These are open questions in physics, and so any arguments grounded in these mysteries will generate inconclusive results.
So we’ll sidestep these empirical issues and think about things logically; using the most elementary laws of logic, we know that either:
- The universe came into existence at a certain point; in other words, there was a time in which the universe did not exist and a subsequent time in which it did, or
- The universe has always existed, with no beginning.
For the universe to have always existed, it must have existed for an infinite amount of time. But what can it mean to say that time is infinite?
Temporal events happen in succession by adding units of time or processes of change. You can add an hour to the previous 24 hours and get 25 hours. Every time you increase time by an hour, you increase the increment of time that has passed by an hour. Since an hour can always be added, this represents a potential infinity. If the universe if 13 billion years old, in one billion years, the universe will be 14 billion years old, and as long as the universe continues to exist, you can always add potentially infinite more time, but only because the universe had a starting point.
But what do you get when you add a billion years to infinite time, which is an example of an actual infinity, as opposed to a potential infinity? If time is actually infinite, then there can be no beginning and no end. And so by adding a billion years to an already completed set results in no change and thus a paradox. Infinity plus 1 billion is the same as infinity plus 2 billion, 3 billion, and so on, which is logically incoherent and shows the impossibility of the passage of time in an infinite universe.
Therefore, we are compelled to conclude that the universe had a beginning—and hasn’t existed for an infinite time—which modern cosmology does seem to support, even if inconclusively.
If you were to make the case that time was created by the Big Bang, and that to ask about time before this is incoherent, one can always ask why, in the absence of time, the Big Bang happened at all? What was the driving force behind this event, this creation of time? Did it just happen, for no reason, out of nothing?
Time itself is a measure of some change. Without any kind or variety of change, it seems impossible to conceive of time passing. So if time did not exist before the Big Bang, and therefore change did not exist, then what could have prompted the transition from nothing to the existence of matter, change, and time?
Now, if it can be shown that time is in some sense an illusion, or that an actual infinity is in fact possible, then the cosmological argument is invalid right from the start, as some physicists and mathematicians maintain. Perhaps they are right, but for the sake of argument, let’s accept that the universe had a beginning to see where the cosmological argument takes us.
The Kalam cosmological argument
In its most compact form, the Kalam cosmological argument can be stated as follows:
- Whatever begins to exist has a cause;
- The universe began to exist;
- Therefore, the universe has a cause.
We have already provisionally accepted premise 2, that the universe had a beginning. Should we also accept premise 1, that everything that begins to exist must have a cause?
There are reasons to question this assumption. It is difficult to know, a priori, whether or not the universe in its totality requires a cause in the same way its constituent elements do. Is this not an example of the fallacy of composition, or the error of assuming that what is true of the individual members of a group is true for the group as a whole?
For example, we can say that no atoms individually are alive, but this doesn’t imply that animals made up of atoms are also not alive. For the same reason, it could be the case that everything within the universe requires a cause, but this does not imply that the universe, as the aggregate of all things requiring a cause, itself requires a cause.
A restatement of the argument makes the fallacy of composition clearer:
- Whatever begins to exist within the universe has a cause within the universe;
- The universe began to exist;
- Therefore, the universe has a cause outside of the universe.
The premise that “everything that begins to exist has a cause” is an inductive inference based on our experience of objects within the universe. It is an illegitimate move, however, to apply this generalization to the beginning of the universe itself, or to any possible universe, to which we have no relevant experience. And so what appeared to be a deductively certain argument is shown to be a weaker inductive inference.
Additionally, it could be pointed out that if causation itself is simply a construct of the mind, and not part of the fabric of the universe, then premise 1 is not necessarily true in cosmological terms (only in psychological terms), adding another layer of doubt.
So you can see that accepting premise 1 (and premise 2) as true involves answering deep questions about the nature of causality, the nature of time, and the possibility of actual infinite sets, not to mention quantum indeterminacy and the possibility of, as in the book title by physicist Lawrence Krauss, “A Universe from Nothing.”
All of this should, at the very least, provoke a strong sense of humility and a deep suspicion regarding the idea that the deepest mysteries of the universe have been solved by two premises and a conclusion.
Again, for the sake of argument, and despite the uncertainty, let’s accept premise 1 anyway, because by accepting the logic of the entire argument, we’ll reveal its biggest flaw. (If you read the last post on the ontological argument, you’ll notice that we used the same strategy, namely, using the argument’s logic against itself. This is proving to be a reliable strategy for all arguments for the existence of God.)
The self-refuting logic of the cosmological argument
The clearest way to present this objection is as follows:
- Whatever begins to exist has a cause;
- God began to exist;
- Therefore, God has a cause.
Remember, Craig is arguing against the possibility of an actual infinity. If God didn’t have a cause, then He has always existed, and therefore has existed for an infinite amount of time. But since you can’t count backwards from infinity, it is a contradiction to suggest that God created the universe at any particular point in time. So, if God created the universe, then God must have begun to exist at a certain point himself.
Since whatever begins to exist must have a cause, God also must have a cause. But it is not possible for God to cause himself, because that would require God to already exist prior to himself, which is a contradiction. God must therefore have an external cause, which must also have its own cause, ad infinitum, resulting in an infinite regress.
If Craig wants to make the claim that God did not begin to exist, then he is contradicting his own earlier claim that an actual infinite is impossible. This is simply a case of special pleading. Craig is claiming that the universe requires a beginning because an actual infinite is impossible, but that God does not require a beginning because God is—for unargued and unspecified reasons—immune from such logical constraints.
And what would it really mean to say that God exists outside of time? It could mean outside of our own time, but the creation of the universe in six days—for example as described in the Bible—implies that God is operating according to some conception of time. And any conception of time (or change) introduces the problem of infinity.
Remember that Ockham’s razor (if you feel compelled to use it) is a principle that states that “entities should not be multiplied without necessity.” If you are willing to state that an entity can exist without cause or without a beginning, then Ockham’s razor suggests that you should select the universe itself rather than an additional entity called “God.”
The bottom line is that the cosmological argument does not appear to solve anything; it simply pushes back the question. If we couldn’t explain the origin of the universe before, we now have an even less accessible entity going by the name of “God” that is susceptible to all of the same problems associated with origin, causation, and time.
I’ll mention one final point; all that the cosmological argument accomplishes—if it accomplishes anything at all—is the establishment of some sort of first cause. But it should be obvious to any careful thinker that the jump from first-cause to the monotheistic God of the Abrahamic tradition is a complete non sequitur. At best, the cosmological argument leads to deism, not necessarily to theism.
It appears to be the case that whether or not you find the cosmological argument persuasive depends on whether or not you think it is a justifiable move to exempt God from the impossibility of an actual infinity. Those that find the argument unpersuasive see the invocation of God, as an uncaused agent, to be a blatant case of special pleading, while those that find the argument persuasive see God as the only plausible way to stop an infinite regress. And it is at precisely this point that the impasse, between the more thoughtful theists and atheists, is reached.
For what it’s worth, I don’t find the cosmological argument persuasive because I find little reason to exempt God—however He is to be conceived—from the logical constraints we place on the universe. While I do think that the cosmological argument is the strongest argument for God’s existence, and I sympathize with those wishing to prevent an infinite regress of causation, the argument simply leaves too many questions unanswered. It provides essentially no insight into the nature of God, and it even fails to establish that there can be only one God. There could be several gods with various natures even if we accepted the conclusion of the argument.
Additionally, it introduces further questions as to how God can exist outside of time and space and yet interact with the universe, and it leaves unanswered what God might have been doing before the universe was created, and what He’ll do when it ceases to exist. It introduces the difficulty of explaining, if God exists outside of time and space, and therefore outside of the universe, how He was able to create the material of the universe from nothing. It appears that if you believe in God, you must still believe that “something came from nothing,” unless you claim that God worked with pre-existing materials, in which case, God becomes potentially superfluous.
Let’s call this the material cause dilemma:
Did God create the universe from nothing, or from preexisting materials?
If you select the first option, then you’re admitting the possibility of something coming from nothing, which most theists deny. If you select the second option, then you’re admitting that the material of the universe was not created by God, which theists also deny. Ether answer shows why God is not an intellectually satisfying solution to the problem of a first cause.
- The Kalām Cosmological Argument by William L. Craig
- Did God Create the Universe from Nothing?: Countering William Lane Craig’s Kalam Cosmological Argument by Jonathan MS Pearce
- Five Proofs of the Existence of God by Edward Feser
- The God Argument: The Case against Religion and for Humanism by A. C. Grayling
- A Universe from Nothing: Why There Is Something Rather than Nothing by Lawrence Krauss
- Saint Thomas Aquinas: Five Ways to prove that God Exists
- Cosmological Argument: Stanford Encyclopedia of Philosophy