Necessary Being? An Introduction To Cosmological Arguments For Theism

"All of this needs to come from somewhere, don't you think?' If we asked all theists to give us their reasons for believing in some kind of "Great Watchmaker', I'm pretty sure a good number of them would answer along these lines. Many of us find it very difficult to accept that the world as we experience it, both through science and in our everyday lives, could exist without cause. Cosmological arguments, which go back at least as far as Aristotle and his "Unmoved mover', are really just articulations of this common-sense intuition. If the God-question matters to you, then, a gentle introduction to cosmological arguments is in order.

Let's assume, for the sake of this post, the following principle: "everything is either dependent or necessary". Take "dependent' to mean "depends on something outside of itself for its existence'. Take "necessary' to mean "could not not have existed'. This, in essence, is a fancy way of saying "things don't randomly pop out of nowhere" & if it could have been true that you don't exist (i.e. you're not necessary), then you must depend on something outside of yourself for your existence (e.g. your mom and dad).

We could criticize this principle. But I'll leave that for another post. The kind of cosmological argument that we'll be looking at claims that we can infer, from this principle, the existence of a necessary being (NB), on which all dependent things ultimately depend. We should ask whether this inference is warranted.

How is this argument supposed to work? If everything is either dependent or necessary, the theist tells us, then, either 1) there are both necessary and dependent things, or 2) everything is dependent. But it cannot be that everything is dependent, because that would result in an infinite regress of dependence: "what does x depend on? On y. But what does y depend on? On z. But what does z depend on? &' and so on,ad infinitum. Hence, we are told, we need something to stop the regress, a being such that "x ultimately depends on NB, which, as a necessary being, doesn't itself depend on anything'. Therefore, there exists a necessary being.

But the obvious reply here is, what's wrong with an infinite regress? Sure, regresses are deeply unsatisfying & intuitively, we'd much prefer some "ultimate ground' for everything that exists, to a chain of dependence that goes back forever. But this might just be a problem with us. After all, infinite regresses break no laws of logic. And we can't reject them on the sole basis that we don't like them.

There are many ways in which theists can try to deal with this worry, but I'll only put forward one of them (the following discussion is heavily inspired by Ross P. Cameron's paper, Turtles all the way down, which I strongly recommend).

The study of phylogenetics attempts to discover the evolutionary origins of heritable traits, like, for instance, warm-bloodedness. Consider the following phylogenetic tree:

This reads somewhat like your average family tree & the tips indicate descendants, while the nodes indicate common ancestors. Suppose we are trying to explain why birds and dogs are warm-blooded, and fishes and frogs aren't. According to this tree, this is because birds and dogs have a common ancestral species which was itself warm-blooded. But now, consider another tree:

On this second theory, the trait "warm-bloodedness' emerged, not once, but twice: once in each of the lineages leading to birds and dogs respectively. Notice that each of our theories is of equal explanatory power, as both provide a reasonable explanation for why birds and dogs are warm-blooded, while fishes and frogs aren't. Let us imagine that no additional empirical data can help us decide which one is best supported. Which theory, then, should we choose?

The law of parsimony ("Ockham's razor') tells us that, all things equal, we should pick the theory that is most unifying. Explanatory unification is achieved when a single explanation can explain more than one phenomenon. A more unifying theory, then, is one that can account for the evidence using fewer explanations. The first theory hasone explanation for the warm-bloodedness of both birds and dogs, while the second puts forward two explanations. Therefore, until we find new reasons for doing otherwise, we must hold the first theory as superior to the second.

What does this have to do with cosmological arguments? In our case, we have two theories: "NB-theory' and "regress-theory'. Both could explain why the world as we know it exists, which was our initial question. But on NB-theory, there is one being on which everything else ultimately depends, and thus one ultimate explanation for everything. Contrast this to regress-theory, on which there isn't one unifying explanation for everything, but rather an infinite number of little explanations for each particular thing. Assuming, as is reasonable, that no empirical data favours regress-theory over NB-theory, we should hold the latter as superior to the former as a theory of why the world exists. Therefore, it is more reasonable to think that there is an NB.

At this point, it would be tempting to protest that this is far too bold a conclusion. Why should the universe comply with our theoretical expectations? For all we know, explanatory unification doesn't make a theory any more likely to be true & it just makes it more pragmatic. Perhaps it is not true that the world is more likely to be simple than complicated.

But this objection has a cost, namely, the threat of scientific anti-realism, the view that our scientific theories don't reflect literal truth. If considerations of parsimony are irrelevant to truth, then, given their key role in theory choice (as described above, with the phylogenetic case), anti-realism seems difficult to avoid.

This may or may not be a problem, depending on the particular brand of atheism you subscribe to. If you're of a "postmodern' bent, chances are you think both science and metaphysics are social constructs anyway. If, on the other hand, you're at Dawkins' end of the spectrum, regarding empirical science as supreme with respect to knowledge of the world, scientific anti-realism is the last thing you want. The above objection would hence not be available to you.

What this objection does call for is a certain degree of humility & the argument gives no hard proof for the existence of a necessary being, it only shows that believing such a being exists is the more reasonable option. But this is by no means unique to cosmological arguments. Neither philosophy nor (more controversially) science are generally in the business of giving hard proofs. Most of the time, "X is reasonable' is the best we can get. To object that the argument doesn't give us proof is thus misplaced.

I conclude that, the existence of a necessary being is supported. But of course, that isn't enough: why should we identify a necessary being with God, or anything like God? See you next time for the so-called "identification stage' of the cosmological argument.