First read this piece by St. Feser:

So you think you understand the Cosmological Argument?

about the traditional structure of Cosmological Arguments, rebutting several popular misconceptions.

Now take the following argument scheme, making suitable choices as needed:

(Major Premise) Every [thing/event] with property X needs a [cause/explanation/reason] outside of itself to [cause/explain/be the reason of it]

. (Minor Premise) There is at least one [thing/event] with property X.

. (Inductive Principle) You have a choice...

A. argue that an infinite regress of [causes/explanations/reasons] for the X's is unreasonable, OR

B. argue that such an infinite causal chain would itself have property X, OR

C. argue that the entire set of X's taken together (which might, depending on X, include the entire physical universe we know and love) has property X.

. (Conclusion) Tracing back the [causes/explanations/reasons] back to their ultimate origin, we find that there is [one/at least one] thing which does not have property X, which, taken [singly/together], [causes/explains/gives the reason for] all the things which do have property X.

. (Atheist Baiting) Add the famous words: "And this all men call God". Works best if ~X is a traditional divine attribute, or even better if you can collect several such ~X's and can argue that they all refer to one and the same Exalted Being!

For example, in the debate, St. Craig's kalam argument used "comes into existence" as X, and then used a lumping strategy (3C) to talk about the universe as a whole and ask whether it had a cause. This form of the Cosmological Argument ended up being strongly dependent on what the Science of the Big Bang actually shows, but most forms don't really depend that strongly on Science.

Other traditional X's include "changing with time", "contingent" (something that might or might not exist), "composite", and some other possibilities mentioned in the link above. The idea is that there are some features of objects which make us seek out causes for them, for example if an object is composed of several disparate objects, we naturally want to know what brought them together. Depending on what you pick for X, the Cosmological Argument may be more or less plausible.

You will also want to consider what type of causal concept you want to include in your argument. A key question is how we know there is such a thing as causation? If it is primarily for empirical reasons, then presumably we know about it through some type of inductive argument from experience, in which case we could wonder how applicable it will be in unusual situations. On the other hand, if it is primarily motivated by reason, through analyzing what types of explanations would make sense of the universe, it may be less dependent on observation. Or perhaps the truth is somewhere in the middle.

Another thing to figure out is what types of entities are connected by cause-effect relationships. Does a cause have to determine the effect with certainty, or is it sufficient if it in some way produces it? For example, if we want to argue that all contingent things were caused by something which is necessary, this is a contradiction in terms unless a necessary thing can produce contingent things, i.e. if causes don't have to be deterministic. A related question: when we talk about causes, are we primarily talking about beings causing things to happen (a.k.a. agent-causation), or states of affairs causing things to happen (a.k.a. event-causation), or both?



Regarding step (5), note that excessively glib atheist baiting obscures the fact that nearly everyone should accept some type of Cosmological Argument, even if they don't necessarily take it to a Theistic conclusion! If you are going to talk about causes/explanations/reasons AT ALL (and I really don't see how to avoid this) then you really need an account concerning the domain to which the concept is applicable. And then it is an interesting fact, that either you must accept infinite or circular chains of [causation/explanation/reasons] or you end up going outside the domain to something else which is different.

This type of reasoning should be interesting, even if you are an atheist. The trouble is, if people only encounter Cosmological Arguments in the context of Theism, then Atheists adopt an argumentative approach where they just feel the need to poke a few holes in the arguments and then retreat to where they were before. This doesn't do justice to the fact that there are numerous X's for which the argument's premises are at least plausible, even for people who don't start out committed to any particular religious doctrine.

For example, Carroll himself gives an account of the scope of causation when he says:

Why should we expect that there are causes or explanations or a reason why in the universe in which we live? It’s because the physical world inside of which we’re embedded has two important features. There are unbreakable patterns, laws of physics—things don’t just happen, they obey the laws—and there is an arrow of time stretching from the past to the future. The entropy was lower in the past and increases towards the future. Therefore, when you find some event or state of affairs B today, we can very often trace it back in time to one or a couple of possible predecessor events that we therefore call the cause of that, which leads to B according to the laws of physics. But crucially, both of these features of the universe that allow us to speak the language of causes and effects are completely absent when we talk about the universe as a whole. We don’t think that our universe is part of a bigger ensemble that obeys laws. Even if it’s part of the multiverse, the multiverse is not part of a bigger ensemble that obeys laws. Therefore, nothing gives us the right to demand some kind of external cause.

There seem to be some question-begging moves in this paragraph, but leave that aside. My point is that Carroll gives a positive account of when he thinks makes the notion of [cause/explanations] make sense. He endorses a version of (1) whereby the concept of causation makes sense if (a) there are laws of nature, understood as unbreakable regularities, and (b) there is a thermodynamical arrow of time whereby entropy increases, making a distinction between the past and the future. (Since causes normally precede effects, but the laws of physics don't strongly distinguish between the two directions of time except through thermodynamics, it seems clear that the arrow of time has to play some role in distinguishing causes from effects in physics.)

He also allows (2) that this concept—though not fundamental in his opinion—nevertheless makes sense for certain particular cases.

Then for (3) he allows us to lump together the universe taken as a whole, but claims that this whole does not meet his criterion (1). He thus comes to an object—the whole universe, apparently—for which, in his view, it wouldn't make sense for it to have a cause (4), although he does not identify it with God (5). Thus his reasoning has an implicit atheist version of the Cosmological Argument behind it. Though one can certainly question whether the metaphysical assumptions behind this claim are right.

But it's just possible you came here hoping, not to construct your own Cosmological Argument, nor to deconstruct Carroll's, but instead to find out what I think about it, something which you may think I have postponed saying for quite long enough. Well, it just so happens that I've written a 16,000 word essay on the Cosmological Argument and related topics, and will be posting it in installments over the course of the next few weeks.