Lawrence Krauss caused quite a stir with his claim that physics – and, in particular, his book A Universe from Nothing – could explain why the universe exists. In his afterword Richard Dawkins claims that Krauss has torn up ” the last remaining trump card of the theologian, ‘Why is there something rather than nothing?” This is sometimes referred to as the “cosmological argument”; and it is worth evaluating because thinkers from Plato to Leibniz , from Wittgenstein to Sartre to Weinberg have all wondered why there is something rather than nothing. The cosmological argument insists that theism provides the only reasonable answer to that question. There are several versions of this argument that seem persuasive. Here we will focus on cosmological arguments that ask “what is the explanation for the universe’s existence?”
One such argument is based on the principle that there is some explanation for everything that happens or exists. This idea seems compelling. Scientists and historians examine the world believing that there are explanations for the facts they discover; they do not do so in vain. But if laws of nature, billions of fundamental particles, relativistic quantum fields – if entire universes, in effect – can exist without explanation, why should we assume that there are explanations for everything that happens in the universe? Why not give up when we fail to find explanations for something mysterious. There is good reason to accept the principle, whereas denying it seems to lead to scepticism.
So we need to provide an explanation for the existence of the universe. Now some speculative physicists have tried to demonstrate that the universe could come to exist out of nothing. We should note that they have conceded that we should not treat the existence of the universe as a brute fact, in no need of further explanation. We should also note that “nothing” always turns out to be “something”. These accounts always make use of laws of nature and strange fields or unimaginable forces. By “nothing” they mean “nothing-like-our-space-time-universe”.
But in metaphysics, and indeed, in ordinary language, “nothing” typically means “nothing- at -all!” No laws, no energy, no potential, no activity; this is why we cannot imagine “nothing”. We immediately think of a black, empty space. In which case, of course, we are imagining something. We are imagining a space and darkness. But nothing actually means “non-being”; there isn’t anything to imagine. It cannot be described by the laws of physics. There is nothing to describe!
Perhaps we could argue that each state of the universe is explained by the state just prior to that. If scientists explain, one by one, all the physical reactions and transformations that have taken place within the universe won’t they explain why the whole universe exists? And suppose the universe is infinitely old. Each state of the universe will then have a full explanation. Won’t we have an explanation for the existence of the universe at that point?
Unfortunately, this does not seem to be the case. By explaining each physical transformation and reaction in the universe we don’t answer the question “why can transformations or reactions happen at all?” Even if there are infinitely many events, we are still left with the questions – “where did this infinitely long series of events come from? Why does it involve these laws and not others? Why is any of this happening?”
It is impossible for physics to give an ultimate explanation for the universe. Physics describes a system: a collection of objects – the basic “stuff” of the universe, if you like (for example particles or fields). There are also rules – or laws of nature – which tell us all the possible states of a system and how that system can evolve over time from one state into another. As Sean Carroll explains:
Ever since Newton, the paradigm for fundamental physics has been the same, and includes three pieces. First, there is the “space of states”: basically, a list of all the possible configurations the universe could conceivably be in. Second, there is some particular state representing the universe at some time, typically taken to be the present. Third, there is some rule for saying how the universe evolves with time.
Now, what physics cannot explain is why the basic stuff exists or why there are rules that govern its behaviour. In other words, physics cannot tell us why a system exists and why it is governed by laws of nature. In other words, physics cannot tell us why there is something rather than nothing. Lawrence Krauss suggests relativistic quantum fields are the basic stuff of the universe and that these are governed by the laws of relativistic quantum field theories. Now, interestingly, particles are not part of the basic stuff of the universe on such theories. Rather, they are understood as specific arrangements of the fields. And the fields can be arranged so that there are no particles at all in the universe (what is called a “vacuum state”).
Krauss thinks that such vacuum states are “unstable” and this can explain why there is something rather than nothing; but if the universe we observe today emerged from a vacuum state it would not have come out of “nothing”! Relativistic-quantum-field-theoretical vacuum states are physical states and Krauss would not have explained those! Furthermore, Krauss would not have explained the laws of nature. Suppose the laws of quantum mechanics are explained by some deeper law. Well, what is the explanation for that law? Physics presupposes laws of nature: it cannot, ultimately, explain them.
But why should we look for a creator to explain the universe? Well, we have already argued that everything that exists has an explanation for its existence; and the universe cannot explain its own existence, and science cannot explain the universe’s existence. So theism seems like a live option. Here we can introduce another principle: we should push our explorations as far as possible; we should try to understand as much as we possibly can. A good explanation will have power – it will make our observations seem less surprising; it will also account for the evidence as simply as possible. However, sooner or later we will reach a stopping point. When our explanations no longer enlighten the evidence, when they become more and more complex, when they make the facts seem more mysterious, we will have reached the limits of our understanding. We need a stopping point for our explanations; and, when explaining the existence of the universe it seems reasonable to make God that stopping point.
There are two types of explanation. Scientific explanations deal with impersonal objects and laws of nature; we observe and measure how some events regularly follow others. We then use our knowledge of those regularities to explain some state of affairs. But we are asking why there are impersonal objects, and why there are laws of nature! So there cannot be a scientific explanation for the existence of the universe, because there can be no such explanation without laws of nature and the physical objects they describe. Yet that is exactly what we are trying to explain when we ask “why does the universe exist?”However, there are also agent explanations. These do not depend on impersonal objects and laws; rather, they describe an agent’s powers, and then give reasons why such an agent would want to bring an event about. We all know what a person, or an agent, is. We can’t help but think of ourselves, and others, as agents who have purposes and act on those purposes. This is how we explain and predict what other people do.
Theism provides an agent explanation for our universe. It describes an agent, God, who has the power to bring the universe about. And God would have good reasons to bring an ordered universe about; it allows him to create things of beauty and wonder. If God exists, by definition, he could not be explained by anything outside himself. God could not have a beginning; whereas it is at the very least possible that the universe has a beginning. At this point we can give no further explanation; because God is unlimited in power, there is nothing outside God that could explain his existence. We cannot gain any more understanding in this area, so our enquiry is complete
There are other reasons for thinking that God is the best stopping point for our explanation: the differences between God and the universe strongly suggest that God is a suitable terminating point for explanation since, if he exists, he must be the terminating point. If God exists (and most atheists grant that this possibility) there could not be any cause of his existence and so his existence could not be explained by anything outside of himself. By contrast, it seems entirely possible that the universe could have a cause and hence an explanation. Second, if God exists, there could not have been a beginning to his existence, whereas there is good evidence that our universe probably did have a beginning (and it certainly could have had a beginning)
Third, many theists have argued that if God exists his existence is necessary in the sense that he could not have failed to exist.By contrast, the universe appears to be contingent: if it has an explanation, it must be explained by something beyond itself. Why think that God’s existence is “necessary”? What does that mean? If God is a “Necessary Being” no matter what else is true, then God must exist. It is impossible for God not to exist! To understand that, we need to reflect on the meaning of “God” (and atheists must reflect on the meaning of “God”: one cannot reject an hypothesis before one even considers what that hypothesis means!)
God is defined as a maximally great being (MGB) – the greatest thing that we can conceive. Why would we define God as a “Maximally Great Being”? Well, God is meant to be the being most worthy of worship. If there was a being greater than God, it would be most worthy of worship.So, by definition, if God exists God is a Maximally Great Being. Theism fills out that definition by describing God as having at least four properties. (i) Maximal Power (ii) Maximal Knowledge (iii) Personhood (iv) Self-existent. “Maximal knowledge” and “Maximal power” simply mean that there are no limits on what God knows and what God can do, other than the limits of what is logically possible. Now physical beings have limitations by nature – the physical universe is limited by time and space and energy. So if there is a God he would have to transcend the limitations of the physical universe.
“Personhood” simply means that God has beliefs, is free to choose and to make plans, and he can bring some of his desires about. That’s all it takes to be a person. “Self-existent” just means that nothing made God, and God made everything else. Nothing else made God, and everything else that exists depends on him to exist. That is to say, God depends on nothing else for his existence. So God is unlimited, personal power. We all know what it is to be personal: to be thinking, conscious beings. We can all readily experience personal power – this is simply the power to make choices. Our power is quite limited in nature, as we are finite physical beings. As sole creator, God’s power and awareness could not be limited by anything else. So, because God would be aware of everything that he could do, and everything that he has done, God would know every truth. This idea of God is perfectly meaningful; and if science has taught us anything it is that we should not dismiss an idea because it seems strange or difficult to imagine.
So what explains God? Well, nothing external to God. If that were the case, God would be dependent on something else for his existence, and he would not be the MGB. Asking “who made God?” is rather like asking “what does the colour red sound like?” It simply indicates that you don’t understand the concept in question. Because God simply is unlimited intentional power – or less technically, unlimited power and love – nothing can limit God. No force or state of affairs could prevent God’s existence.
So everything that exists has an explanation, including God. God is only limited by his choices and the laws of logic. And God has the power to bring the universe about. The universe is limited because it is composed of limited physical forces and particles. So here is the key point: unlike the universe, God is explained by his own nature. God is what philosophers describe as a “Necessary Being” – no matter what else is true, God must exist. It is impossible for God not to exist! This is why God’s existence needs no further explanation and God can explain the existence of the universe.
David Albert “On the Origin of Everything ‘A Universe From Nothing,’ by Lawrence M. Krauss” http://www.nytimes.com/2012/03/25/books/review/a-universe-from-nothing-by-lawrence-m-krauss.html?pagewanted=all (retrieved 15/11/14)
Lawrence Krauss A Universe from Nothing
Alexander Pruss and Richard M. Gale, “Cosmological and teleological arguments”, in: William J. Wainwright (ed.), Oxford Handbook of Philosophy of Religion, Oxford: Oxford University Press, 2005
Alexander Pruss “The Leibnizian Cosmological Argument” in: Craig and Moreland (ed.), The Blackwell Companion to Natural Theology (2009)
Richard Swinburne The Existence of God (Oxford:2004)
 Or the “argument from contingent existence”, to distinguish it from the Kalam cosmological argument.
 Carroll goes on to explain
“Quantum mechanics, in particular, is a specific yet very versatile implementation of this scheme. (And quantum field theory is just a particular example of quantum mechanics, not an entirely new way of thinking.) The states are “wave functions,” and the collection of every possible wave function for some given system is “Hilbert space.” The nice thing about Hilbert space is that it’s a very restrictive set of possibilities (because it’s a vector space..); once you tell me how big it is (how many dimensions), you’ve specified your Hilbert space completely. This is in stark contrast with classical mechanics, where the space of states can get extraordinarily complicated. And then there is a little machine — “the Hamiltonian” — that tells you how to evolve from one state to another as time passes. Again, there aren’t really that many kinds of Hamiltonians you can have; once you write down a certain list of numbers (the energy eigenvalues…) you are completely done.”
 See our article “Agent Explanations: a Guide for the Perplexed” for more detail
 Won’t brain science someday replace this way of thinking? Maybe, but probably not. In any case this objection misses the point. We don’t need scientific explanations involving brain states to understand what other people will do. We just need to think of them as rational agents. Agent explanations are non-scientific explanations which are conceptually clear and practically useful. What more can you want from a type of explanation?