The Leibnizian cosmological argument is one of the cosmological arguments for the existence of God and is probably my favorite. The reason is because it gets to the heart of what the theist is arguing for: the existence of a necessary being. Here is how it goes.
Premise 1: anything that exists has an explanation of its existence either in the necessity of its own nature or an external explanation. Premise 2: the universe has an explanation for its existence and that explanation is grounded in a necessary being. Premise 3: the universe exists.
Premise 4: therefore the universe has an explanation of its existence. Premise 5: therefore the explanation of the existence of the universe is grounded in a necessary being. And the conclusion is: God exists.
Now looking at this argument we need to defend these premises for the argument to work. Starting with premise 1, we see it relies on the same reasoning behind Leibnizian principle of sufficient reason or a restrictor version. If we start by denying that everything that exists has an explanation, then it would undermine the very notion of science, since things could just pop into existence without a reason.
It would not need an explanation of how they arrived. We also accept there is sufficient reason for the logical conclusions we form. It would seem ad hoc to deny the PSR, but accept it to attack the PSR.
The conclusions we do come to are backed by reason. As Alexander Pruss says: "once we admit that some contingent state of affairs have no explanations, a completely new skeptical scenario becomes possible: there is no demon deceiving you, but your perceptual states are occurring for no reason at all. .
. Thus we cannot even say that violations of the PSR are improbable, if the PSR is false. " Although Hume was skeptical of causality, he did acknowledge: "If I ask why you believe any particular matter of fact, which you relate, you must tell me some reason: and this reason will be some other fact connected with it, but as you cannot proceed after this manner, an infinitum, you must at least terminate in some fact, which is present to your memory or senses; or must allow that your belief is entirely without foundation.
" So I hardly see premise 1 as being controversial. Premise 2 is where the majority of the objections will lie. The first being is: why can't the universe be necessary in itself and have its own explanation?
Many atheists like Hume argue the universe does in fact exist necessarily and is the foundation we reason everything else from. However given the scientific evidence and the philosophical reasoning we can see that this is most definitely not the case. For the universe to be necessary it must be eternal, meaning it cannot fail to exist; and it must be changeless, meaning it must be as it is, in all possible worlds.
There would be no other way space-time could have been which means hard determinism would follow. Now right off the bat our intuitions tell us otherwise. There seems to be nothing illogical about the possibility that parts of the universe could be different.
But going beyond the mere intuitive possibility, given the Heisenberg Uncertainty Principle, we can see that different measurements on particles could have been performed by an observer resulting in different outcomes. This has recently been confirmed by experiments by Anton Zellinger. In 2011 he and his team confirmed the Kochen-Specker Theorem, which showed that the obtained outcome depends upon the context of the time and cannot be predicted prior.
The abstract of the 2011 experiment says: quantum theory demands that, in contrast to classical physics, not all properties can be simultaneously well defined. The Heisenberg Uncertainty Principle is a manifestation of this fact. So the burden is really on those who argue for hard determinism to show that specific measurements, performed by observers, were preordained; since the evidence in quantum mechanics suggests otherwise.
The other issue to get around is the scientific research which has demonstrated the universe is not eternal and need not exist at all. Both Friedmann and Lemaître working with Einstein's theory of general relativity predicted the universe is expanding and this was empirically confirmed by Edwin Hubble in 1929. This led to the conclusion that an expanding universe must have sprang into existence at some point in the past.
Finally in 1965, two astronomers found the evidence which confirmed this event; which showed the universe sprang into existence from a big bang. They discovered the cosmic microwave background radiation, which was predicted by physicists to be the thermal radiation leftover from the big bang. This evidence confirmed the existence of a finite universe.
However despite this, attempts at eternal universe models have been crafted, but have all failed and recently in 2003 the Borde-Guth-Vilenkin Theorem was presented, demonstrating that any expanding universe cannot be passed eternal. As Vilenkin said in 2006 and is now a famous quote: "It is said that an argument is what convinces reasonable men and a proof is what it takes to convince even an unreasonable man. With the proof now in place, cosmologists can no longer hide behind the possibility of a past-eternal universe.
There is no escape, they have to face the problem of a cosmic beginning. " Now some argue we can avoid the theorem by postulating the universe was contracting prior to expansion. But this is just unreasonable and violates science.
If the universe was contracting it could not have re-expanded. As Vilenkin said in reply to Victor Stenger: "This sounds as if there's nothing wrong with having a contraction prior to expansion. But the problem is that a contracting universe is highly unstable.
Small perturbations would cause it to develop all sorts of messy singularities, so it would never make it to the expanding phase. . .
" So you cannot get around the Borde-Guth-Vilenkin theorem without violating science. There is no escape we have to face the problem of a cosmic beginning. But what about the second part of premise 2: why does the explanation have to be a necessary being?
Why can't it be a multiverse? Well the Borde-Guth-Vilenkin theorem even applies to the multiverse and higher levels of brain cosmology. But for the sake of argument: perhaps the universe did come from just a necessary existing substance instead of a necessary being.
Why do we have to appeal to a necessary being? Well we can just say a necessary substance exists and that is the explanation for why contingent things exist. They both avoid the illogical position of an infinite regress, since they are both necessary and uncaused by definition.
Well let's look at these two options. The first is a non-physical necessary mind and has the intelligence and creative ability to create a universe or a multiverse. But the second is simply a substance that just exists.
So for it to create the universe, it has to be able to do something by itself. So it would have to be conscious as a non-conscious substance cannot cause itself to create something contingent. So agent causation follows instead of event causation because event causation would result in an infinite regress of events without a final explanation.
It also cannot be made of any substance we know of in the universe, since this would mean it is made of contingent substances. And it would also have to be independent of space-time, since that is also finite. It also must have intelligence to understand how to produce a variety of contingent things and the power to do so.
But then it sounds pretty much like the first option anyway; and it should be obvious: how can any substance act to create a universe without being these things? Which is why we say the explanation of the universe is what we call God. A non-physical conscious substance that is powerful wise and most importantly necessary.
So since premise 3 is just a statement of fact, we can then draw from premise 1 and 3 that the universe has an explanation of its existence. It would be an obvious case of special pleading to argue our universe is the only thing that doesn't have an explanation and just created itself. As the obvious question is: how does nothing collide with nothing to form everything?
But what about the argument that the universe came from nothing like how subatomic particles come into being from nothing? If particles can pop into existence, why can't this be how the universe came about? Well this objection is nothing more than a misunderstanding of physics.
Subatomic particles do not pop into existence from nothing, but from a fluctuation of energy contained in a vacuum. They are not literally coming from nothing but from energy. If the universe came about like a subatomic particle, then it didn't come from nothing, but from some pre-existing substance which came from something else or is necessary of itself.
And in order to avoid an infinite regress, the chain of explanations must end in that of a necessary being Properly speaking, the idea that the universe came from nothing, would be to argue that the universe didn't just come from empty space but from the absence of space, time, matter and energy. And this idea is the biggest leap of faith I've ever heard. So with this premise defended we can then move from premise 2 and 4 that the explanation of the existence of the universe is what we call God; a necessary being.
And anything necessary would have to be able to be a first cause in order to cause something else to exist. So I don't see any reason to deny that a necessary being exists. Other alternatives go against science, violate logic and are just plain ludicrous.
The best and most logical explanation is that a necessary being exists and is the explanation for why the universe exists. Now there are two other possible objections I am expecting. The first is: if the universe is contingent, then how can its explanation be necessary?
If something necessary causes something else, then its effect must also be necessary. So the universe cannot be explained by something necessary. In other words contingent things are only true because of contingent explanations.
So the existence of the universe cannot be explained by a necessary being. Well the important thing about this objection is to note that premise 1 of this version of the argument, was specifically formulated to avoid this objection. Leibnizian in its original premise 1 in PSR seems to presuppose that explanations must entail the facts they explain.
But this is of course false. And this version of the argument avoids that, because premise 1 just says that anything that exists just has an explanation. In 'The Blackwell Companion to Natural Theology' Alexander Pruss says: "When I talk of the PSR, by 'sufficient reason' I mean reasons that are sufficient to explain the explanandum.
Leibniz may have erroneously thought that a reason is only sufficient to explain something that it entails, but we do not need to follow him in his error – and should not, since that route leads to modal fatalism. But if the reader is not convinced, I can just rename the principle I'm defending the 'Principle of Good-Enough Explanation'. " William Lane Craig says on his website: "the theist could maintain that for any contingently existing thing, there is an explanation why that thing exists.
Or again he could assert that everything that exists has an explanation of his existence, either in the necessity of its own nature or in an external cause. These are more modest non-paradoxical and seemingly plausible versions of the PSR. Thus the objection raised by Van Inwagen misses a target – or, more accurately, is aimed at another target.
" So this objection fails, because premise 1 doesn't say an explanation must entail the thing it is explaining. Just that it explains why it is there. No one is arguing non-conceptual explanations must entail the explanandum.
Just that, as Pruss says: "either render the explanandum more probable that it would otherwise be, or at least are explanatory relevant to the explanandum. " What about the argument that we can explain the universe entirely in terms of contingent principles? Alexander Vilenkin suggests this in 'Many Worlds in One', that one day we might be able to explain the universe in purely scientific terms.
However the problem is contingent or scientific principles cannot be the reason something exists. Pruss responds: "A principle cannot by itself pull beings into existence out of a metaphysical magic hat, since a principle itself must be true of something and true in virtue of something. " So principles are simply descriptive accounts of the way things are.
They do not actually stand as the reason concrete things exist. So the Leibnizian Cosmological Argument is a pretty good argument. If we accept the logic of premise 1 and the science behind premise 2 we have to accept the conclusion of a necessary being.
And when looking at the problems of the alternatives the only logical inference we can draw is a necessary being, as the explanation of the universe.
