By David Beck
The term "cosmological argument" (CA) refers to a whole cluster of arguments or patterns of thinking, all of which draw the common conclusion that God is real, based on obervations that things we see around us never exist, unless something else makes them exist. So CA has us think of God as an originating cause, or initiating source of things and events, because there cannot be an infinite series of things that make the things around us exist.
I will concentrate on the original form of CA, first fully stated by Aristotle and best known as developed by Thomas Aquinas, and still used by many contemporary apologists. This argument begins with a simple observation of the world around us. We experience the world as a network of concurrent causal connections. Things are dependent on each other for their very existence, in highly complex systems, such that the whole universe is itself apparently an interconnected system.
The briefest and most general statement of Aquinas' argument is found in chapter 15 of the Summa Contra Gentiles. It is similar to its predecessor in Aristotle. Here he says: "We see things in the world that can exist and can also not exist. Now everything that can exist has a cause. But one cannot go on ad infinitum in causes. Therefore one must posit something the existing of which is necessary." (Summa Contra Gentiles, 15.124, excerpts)
As I see it, there are three basic points in this argument:
Point 1: What we observe and experience in this universe is contingent.
First, this is an observation about the things we see and know about in the real world around us. It is not intended to be about everything in the universe, let alone every possible thing, only what we have actually experienced. Second, the key element in this sequence is "contingent". In this context this means that something owes its existence to something else, it does not exist by itself. It needs a cause.
So the world consists of series of causes, which are in turn connected into systems. That is, A is caused by B, but only as B is caused by C, and so on. Everything we know of possesses this sort of contingency: it exists and functions only as it is caused by other factors in its causal chain. We know of nothing that by itself spontaneously initiates its own causal activity. Again, nothing here turns on our knowing about everything. Even if something does turn out to spontaneously initiate, it would have no effect on CA as we will see later.
Point 2: A system of causally dependent contingent things cannot be infinite.
The idea here is that, regardless of how complex and interconnected, the series or systems of causally related contingent things are not infinite. Aquinas uses the illustration of a hand moving a stick, which in turn is moving a ball. Perhaps the most frequently used picture in recent discussions is the train.
Imagine you are seeing for the first time, a train moving past you. Baffled, you wonder how the boxcar is moving. You come to realize that it is being pulled by another boxcar in front of it, and so on, down the tracks beyond your view.
This picture allows us to visualize the various naturalist's scenarios, so commonly heard in our society that attempts to describe how it is that things come to be in our world. "The cosmos is a great circle of life," we are told. But, stringing boxcars all the way around the world in a circle until the last one hooks up to the first will still not explain the motion of even the first boxcar. And just so, if contingent things cause each other to exist in a closed circle, there is nothing to initiate the causality, nothing ever starts. The naturalist offers perhaps a more promising scenario, "The cosmos is an intricately evolved ecosystem in which everything is related causally to everything else." So boxcars clutter the world in an unimaginably complex system of railroading, such that in some way every boxcar is coupled to and therefore pulling the first one. Still, we have no accounting for the motion of that first boxcar, and likewise, for the existence of actual things in our world.
It is always tempting, of course, to say that it is enough to know that each boxcar is being pulled by the boxcar in front of it. In one sense it is clearly true that boxcar A is pulled by boxcar B. But B can pull A only because at the same time C is pulling B. The pulling action of B is transferred from C. And so it is also true that A is being pulled by C. The same is true, of course, about D, and about E, and so on.
One last option suggests itself. Suppose that there are just infinite boxcars, or as the naturalist says, "The intricacy of the universe is lost in infinite complexity." But infinite boxcars, no matter how complexly arranged, still leave unexplained why our first boxcar is moving and hence why any of them are. Letting the sequence go to infinity fails to explain anything.
Point 3: The system of causally dependent contingent things must be finite.
This last idea simply draws the obvious conclusion from point 2. If the series or system cannot be infinite, then it must be finite. No other option remains, unless one wanted to argue that nothing actually exists. The world is just my private fantasy, some think, but that is hardly a rational option.
Conclusion: There must be a first cause in the system of contingent causes.
If the causal sequence is finite then there must be a first cause regardless of how many causes there might be in the series. This concept of "first cause" brings together two ideas. To say that it is the first cause is to say that it neither requires nor has a cause itself. First is first! So it is fundamentally different from every other cause in the series: it is not contingent. It depends on, is limited by, or exists because of absolutely nothing else. It simply initiates causality.
On the other hand, to say of the conclusion that it is the first cause, is to define its relation to everything else in the series: namely, that it is the cause of them all. It is the cause of all things in that it initiates all of the causal activity, without negating that each cause is, in fact, a cause in its own right of the following one in the series, and is an effect of the proceeding one. This is the full meaning of omnipotence - that quite literally all power has its single source here.
The only explanation for the moving line of boxcars is that somewhere there is a locomotive powerful enough to pull the whole train while it itself does not need to be pulled. So the idea of a first cause is fuller than it might at first appear. It is the initiating cause of existence of everything in the system of causes, and it exists without any cause or dependency whatsoever. It is strictly uncaused. Note that it is not self-caused, as if it had deficiencies or needs that it is capable of supplying by itself. It is strictly uncaused, unlimited, infinite.
There are three kinds of objections that are typically given to this argument. First, certainly the most frequent criticism of CA is that there is no reason to think that the conclusion here is the Christian God - the God of the Bible. Even if it were a sound argument, the objection typically goes, it only gives us a "first cause". This could well be some space/time factor, say the Big Bang Theory, elementary particles, energy state, or even an original vacuum. It certainly does not give us an infinite creator God who loves us and desires relationship and worship.
Now we should certainly agree, strictly speaking, the argument discussed above does not give us a full concept of God in its conclusion. However, what it does give us, that is, that there must be only finite links in every causal system, and thus a first and uncaused cause, is already enough to defeat atheistic naturalism which holds that the universe is a closed causal system, existing on its own, purely by chance, without any external source.
Still the best response is to agree: CA only proves what it proves. Certainly we will want more and different kinds of input about God - other arguments, and especially revelation. People who use this objection often suppose that unless we know everything about God, we do not know anything. This is obviously false. I certainly know much about many things without knowing everything about any of them. I know much that is true about my wife, but would not pretend to know even close to everything.
A second objection says that infinite series are possible after all. Since CA depends on a denial of an infinite series of causes, the argument supposedly fails. The sequence of cardinal numbers, as we all learned in elementary school, is infinite. We could assign a cardinal number to each member of any causal sequence and we would then have an infinite sequence of causes.
This objection occurs in many forms, but they all overlook the specifics of the system of causes in CA. There are four characteristics of this series. Each is crucial to eliminating the possibility of infinity. (1) It is a system: an interconnected network of causes and effects. (2) Each cause is itself contingent: each in turn, itself needs a cause. (3) The dependency in the Aristotlelian/Aquinistic CA is concurrent not chronological. It refers to concurrent dependency relations within a system of causes. (4) The specific relation to which the generic CA refers is the causing of existence itself. The key point in CA is that there cannot be an infinite series of causes with all four of the above characteristics, not that there cannot be infinite series of other types, including some closely similar types, such as sequences of causes in time, like parent/child relationships.
Note that, given this point, it is irrelevant to the argument whether the universe itself might be infinite in any sense. Aquinas thought that it is at least possible that the universe exists in infinite time, as Aristotle had held. He held that we know only from the Bible that God created the universe at a beginning of time. The argument shows only that there cannot be an infinite sequence of concurrent dependent causes of the existence of things.
A third typical objection holds that we do not know about the whole universe and therefore cannot begin the argument with a statement about the whole universe. We do not know if everything is contingent. The simplest way to answer this is to admit that it is true, but note that we did not and on purpose avoided, any mention of all things or of the whole universe. The conclusion holds regardless. Furthermore, the argument shows that if there is something else that is not contingent, then it is by definition uncaused and therefore cannot be the big bang, or some particle, or any other contingent event or thing.
At worst this would mean that there are multiple Gods. Granted, CA by itself does not eliminate that. However, Aquinas learned from Aristotle, and in fact Parmenides had it even earlier, that there could only be a single uncaused or infinite being. Any second infinite would have to differ from the first in some way, but an infinite being cannot be either more or less than anything. We all learned early on that infinity minus or plus anything is still infinity. So there can only be one infinite God.
It is clear that Aquinas intended this argument to play a critical role in our understanding, not just of God and religion, but as it did for Aristotle as well, of everything. What it says is that we cannot make sense of our reality at all apart from God. The God of the cosmological argument best explains life as we experience it.