The cosmological argument for the existence of God has taken many different forms for hundreds of years. However, the version that I take to be the most powerful, as some readers of my blog know, is the argument from contingency. And it is this version that I will be presently defending, as well as answering common objections put forward against it.
The termsBefore promulgating the argument I feel it necessary to define the terms being used (i.e. contingency and necessity). Now, there are different (though not contradictory) definitions of contingency, so let me spell these out. Something is contingent if: (1) it exists, but could have possibly failed to exist, or (2) it is not of the nature of it to exist, or (3) its nature can be contemplated without simultaneously contemplating its existence.
Let me now expand these definitions so as to illuminate how they each entail contingency. If some existent X satisfies (1) then, to reiterate, it is possible that X could not have been. But this necessarily entails that it is not of the nature of X to exist. For if it was of the nature of X to exist, then it could not be possible for it to fail to exist. (My claim here is that if it is of the nature of X to be Y, then you cannot have X without Y. As an example, if it is of the nature of a triangle to have three sides then it is not possible for an triangle to fail to have three sides.) This point seems to lead us directly to (2), and thus our first two definitions go hand in hand. Now what this means is that if it is not of X’s nature to exist, then X does not contain the reason for its own existence, and thus it must derive its existence from something else.
Let’s take a look at (3). If I can contemplate the nature of X without simultaneously contemplating its existence, then this entails the fact that it is not of the nature of X to exist—otherwise contemplating the nature of X would be to simultaneously contemplate its existence. Thus we see that (3) leads to contingency for the same reasons as (1) and (2).
From what precedes it should be obvious how we can define necessary. Something is necessary if it is non-contingent. That is to say, something is necessary if it is not possible for it to not exist (i.e. it must exist), or if it is of its very nature to exist, or if contemplating its nature entails simultaneously contemplating its existence.
The argumentIt is now appropriate to state the argument from contingency, and note that the term contingency in the argument can take the form of any of the above definitions:
1) If something is contingent, then it derives its existence from something outside of itself.2) The universe is contingent.
3) Therefore, the universe derives its existence from something outside of itself.The argument is logically valid, that is, the conclusion follows necessarily from the premises. But the question can be posed regarding its soundness, so let us go about demonstrating the premises. Premise 1) seems to follow necessarily from the definitions of contingency given above. To reiterate, if it’s possible that X could (have) fail(ed) to exist, then the reason for its existence is not contained within its own nature, and thus it must be contained in the existence of something else—and this thing would be where X derives its existence from. Premise 1) then seems to be on quite solid ground.
Let us now turn to what is most likely the premise that a naturalist will find most fault with, namely, premise 2). The easiest way to demonstrate premise 2) is to demonstrate that the universe satisfies the definition(s) of contingency. So, the first thing we can ask is whether it is possible for the universe to have failed to exist. Here we might meet some resistance. First, what exactly is meant by the universe, and how do we know that we can conceive of it failing to exist? Well, by universe I simply mean “all matter, energy, and space-time,” and therefore this includes not only our observable universe, but any meta-universe(s), if you will. Subsequently, to say that we can conceive of matter, energy, and space-time not existing does not seem to bring forth any inherent difficulty. That is to say, there is no contradiction or incoherence in such a statement, and thus I see no claim for inconceivability that could be made here. (Note that something is said to be metaphysically possible if it is conceivable.)What about the second definition of contingency? Does the nature of the universe contain the reason for its own existence? I don’t see how it does, in that having the nature of being all matter, energy, and space-time does not tell us why all matter, energy and space-time actually exist in the first place. That is, there is nothing in matter, energy and space-time together (or even apart) that tell us that it must exist. This goes hand in hand with the third definition of contingency. That is, I can contemplate the nature of the universe without simultaneously contemplating its existence. But if I can do this, then the reason for the existence of the universe is not found within itself.
What this demonstrates then is that the universe—all matter, energy, space and time—satisfies all three definitions of contingency, and thus the premises of the above argument seem to be vindicated. This obviously means that the conclusion is valid and sound, and therefore the universe necessarily derives its existence from something else.
ObjectionsIt should go without saying that the naturalist will not take this argument lying down, nor would I expect one to do so. There are many arguments or objections that could be leveled against the argument from contingency, and while I cannot deal with all of them here, I will currently try to deal with the most penetrating and popular ones.
(a) How do we know that what the universe derives its existence from is God? There is nothing logically wrong with claiming that perhaps the universe derives its existence from something that is itself contingent. However, this only pushes the problem back a step further, for then this thing requires an account for its existence. The point here is that we must, at some point, admit of something which is non-contingent, that is, necessary—something that cannot fail to exist. This would be something whose nature contains the reason for its own existence, and whose nature we can contemplate while simultaneously contemplating its existence. This thing then just would be existence, that is, it would be pure existence, or pure being. And surely this is worthy of earning the name “God.”(b) Why admit of something necessary? Why can’t we have an infinite series of contingent beings? I will not answer this objection by asserting that an actual infinity cannot exist. For this is something that it seems even mathematicians and philosophers cannot agree on. Rather, my argument is that a chain of contingent beings remains contingent. Now, before one levels a fallacy of composition at me, remember that not every inference from a part to a whole is fallacious. For instance, if every brick in a wall is red, then it does in fact follow that the wall is red. What this means is that claiming that a chain of contingent things is itself contingent commits the fallacy of composition would need to be demonstrated. Moreover, this could be avoided if one simply demonstrates that a collection of contingent things is in fact contingent, and this I plan to do currently.
Physicist Paul Davies explains the problem elegantly:
[I]t is quite wrong to suppose that an infinite chain of explanation is satisfactory on the basis that every member of that chain is explained by the next member. One is still left with the mystery of why that particular chain is the one that exists, or why any chain exists at all.
This point was also made a long time ago by the mathematician Leibniz when he gave an example of an infinite collection of books, of which each book was simply a copy of the content in the previous book. The point being that the content in the books is not accounted for simply because the collection is infinite, and there must be something outside this collection that does account for it. The big picture here, then, is that if we have an infinite collection of individual things of which it is possible for them to fail to exist, then it is possible that the collection in its own right could fail to exist, and thus the infinite chain is still contingent. Therefore something necessary must still be admitted.
(c) Why expect the universe to admit of explanation at all? Why can’t the universe simply be? To claim that the universe (or anything) might escape explanation in principle is to admit of brute facts—in fact, that’s exactly what a brute fact is, namely, a state of affairs which has no explanation for its existence. There are a few problems with this line of reasoning. First, since things are made intelligible by explanation then a brute fact does not have an explanation for itself, and it has no explanation to impart to anything else. This entails that a brute fact cannot be a participant in an explanatory chain, and therefore it certainly cannot be the end of an explanatory chain, as the universe would have to be. (Note that I have argued this at much greater length here.)The second problem is that an object or substance can only either possibly fail to exist, or not. This is to say that something can only either be contingent or necessary. There is no middle ground here, of which a brute fact would have to be. To deny that something can either only be contingent or necessary is to deny the law of excluded middle, and would thus be illogical.
(d) It’s possible that the universe is eternal, and thus it would not be contingent. I have no problem with theoretically granting the possibility of an eternal universe. However, simply asserting that the universe could be eternal does not thereby make it necessary. Let us return to Leibniz’s example of the collection of books to see why this is so, except let us not imagine a collection of books but, rather, simply one book existing eternally. Does the fact that this book has always existed demonstrate that it is necessary? No, because one can still ask why this book exists, has the content that it does, and why this content was not different. The point is that it remains true that nothing about the book, not even its eternality, provides the reason for why it exists at all. To always exist is not the same as existing necessarily, because duration of existence does not enlighten us to the reason of existence. Moreover, duration of existence does not affect a thing’s nature. A triangle is still a triangle, whether it exists for a second or for an infinite amount of seconds.Similarly, it would remain the case that an eternal universe could possibly have been different, or it could have not existed at all. Moreover, it would still remain the case that contemplating the nature of the universe does not entail contemplating its existence. Thus, even an eternal universe satisfies the definition, not of necessity, but of contingency.
There are other objections that can be raised (e.g. “What created God?” or “Why does God exist?”) but I felt the need to only address, what I take to be, the most substantial ones. The point seems to remain that the universe is indeed contingent, and that it ultimately derives its existence from something which is necessary and which we call God. The argument from contingency then seems to be successful.