Christians, and Jews before them, have long seen God’s hand in the wonders of the universe. Psalm 8 begins: “LORD, our Lord, how majestic is your name in all the earth! You have set your glory in the heavens….. When I consider your heavens, the work of your fingers, the moon and the stars, which you have set in place ….” And Hebrews 11:3 affirms: “By faith we understand that the universe was formed at God’s command, so that what is seen was not made out of what was visible.”
It is no wonder then that christians have used the universe in their apologetics as a reason to believe. Two arguments have been prominent: the Cosmological argument about the cause of the universe and the Teleological argument about the design of the universe. But many christians, unfortunately, present the arguments in less than effective ways. I think it helps to keep our thinking clear and rigorous if we adopt the practice of philosophers and understand the arguments in a formal manner, with premises and conclusion, even if we don’t always present it this way.
I have researched the arguments used by a few philosophers and apologists, and believe we can use what these experts teach us to present a strong reason to believe. I have been most impressed by William Lane Craig’s versions of these two arguments in his book Reasonable Faith, and I have based my summary of the arguments on a modified version of his presentations.
The Cosmological argument
This version of the argument is called the ‘Kalam’ argument, named from an Arabic school of philosophy which first developed the argument.
- Whatever begins to exist has a cause external to itself.
- It is impossible for a series of events in time to have no beginning.
- Therefore the universe began to exist at some time.
- Therefore the universe has a cause.
The argument is logically valid, so we need to look at the justification of the two premises.
Premise 1 seems obvious at first glance. Everything we experience and know in the universe has a cause (or many causes), and a thing that doesn’t exist cannot cause itself to exist. Even in quantum physics, where quantum events can occur unpredictably, there are still antecedent conditions which cause the events. So it isn’t much of an extrapolation to say that everything in the universe has a cause, and therefore the universe as a whole has a cause. Notice that the argument doesn’t say “everything has a cause” (then God would have a cause) but “everything that begins to exist” (thus God doesn’t have a cause because he has always existed).
Premise 2 is a little more complicated. There are several ways we might look at it:
- It is impossible to count to infinity, so it is equally impossible to count down from a past infinity to zero (or any other number) – no matter how long we count, even for an infinite time, we cannot reach a finite number because: ∞ – ∞ = ∞ . Thus it is impossible for there to have been an infinite and beginningless series of past events.
- The laws of physics (specifically the second law of thermodynamics) tell us that the universe is “running down”, moving from a state of highly uneven temperature and distribution of matter, to a state of being homogeneous. This is inexorable – though there can be localised times and places where the process reverses, in the long run the second law will apply. But if the universe consisted of a beginningless series of events, every physical process that could occur would have occurred, and the universe would have long since become a homogenous eventless “soup”. The fact that the universe is still dynamic is proof that it hasn’t been around an infinite time.
It seems therefore that the conclusion 3 is justified for the whole universe. (Certainly it is known to be scientifically true for our universe, but science cannot tell us if there was anything before the big bang.) Thus the conclusion that the universe had a cause also seems reasonable.
But what can we know of this cause? Does the argument get us very far?
If the conclusion of the Kalam argument is accepted as true, then some properties of the first cause can be gleaned from the argument. For example, the cause is outside the universe and therefore, by definition, outside of space and time; it must be powerful, beginningless and necessary.
This cause may even be seen to be personal, on the following grounds. We currently only know two types of explanation – scientific (in terms of physical processes and laws, e.g. the plate fell because of gravity) and personal (in terms of a person’s motivations and action, e.g. the plate fell because I wasn’t looking when I put it down). But the cause of the universe is not physical, spatial or temporal, so cannot be scientific – so it seems it must be personal.
There are many counter arguments, the main ones being:
1. Who made God? If God can be uncaused, why can’t the universe?
This rather trivial riposte is surprisingly made by some intelligent critics. It is clearly stated in the argument that God is a necessary being which is eternal and uncaused. However it is clear that the universe is contingent and has a cause (unless we can show that it is the one contingent thing that doesn’t have a cause.
2. How do we know everything has a cause? Quantum physics shows that some things are uncaused, so why not the universe?
However it is not certain that quantum events occur without a cause. It is true that the most accepted quantum models included uncaused events, but other models do not. In any event, they require certain antecedent conditions which are necessary but not complete causes (e.g. the existence of a quantum field, which is far from nothing – especially a quantum field capable of starting the universe!) so the parallel is not really valid.
3. It may be true that we can’t count to infinity from any starting point, but an infinite series never had a starting point.
But this only confirms the fact that we can’t count down from infinity to a number, so neither can an infinite past ever get to now by progressing one year at a time.
This is a strong, common sense argument – most people accept the logic of the universe having a cause. The fact is that scientists don’t have any real alternative explanations (the attempts to use quantum physics are often presented dishonestly).
For a more comprehensive discussion of two versions of the Cosmological argument, and eight different objections, see The cosmological argument.
The teleological argument
- The character of our universe is determined by, or described by, physical laws and constants.
- If these laws and constants had been different, life would probably not have arisen.
- The laws and constants which led to this suitability for life must have been determined by either physical necessity, chance or design.
- The laws and constants have not been determined by physical necessity.
- The laws and constants have not been determined by chance.
- Therefore our universe was designed.
Premise 1 is obvious and uncontroversial, but the remaining premises require justification.
Premise 2 is the conclusion of most cosmologists. For example Martin Rees, one of the world’s most respected cosmologists, and John Gribbon write in ‘Cosmic Coincidences’:
“If we modify the value of one of the fundamental constants, something invariably goes wrong, leading to a universe that is inhospitable to life as we know it …The conditions in our universe really do seem to be uniquely suitable for life forms like ourselves.”
Paul Davies says:
There is now broad agreement among physicists and cosmologists that the universe is in several respects ‘fine-tuned’ for life … [or] rather it is fine-tuned for the building blocks and environments that life requires.
Premise 3 is simply a statement of the possibilities. It is difficult to find any others. The logic is this: Either our universe could have been any different or it couldn’t (physical necessity). If it could have been different, it took this form either because it was designed or not designed (chance).
Premise 4 is the same as saying there is an underlying physical “law” that determines the characteristics of our universe – sometimes called a ‘Theory of Everything’ (ToE). However we can say of a ToE:
- We do not currently have such a theory, and it isn’t certain that we ever will.
- A ToE, as currently conceived, has the purpose of providing a unifed explanation of the four fundamental forces (gravity, electro-magnetism, the weak nuclear force and the strong nuclear force); explaining the universal fine-tuning is way beyond this.
- Many cosmologists say the nature of the fundamental laws and the values of the constants do not seem to allow of such an explanation, and so Martin Rees (in ‘Just Six Numbers’) eliminates underlying physical laws or a ToE from his list of possible explanations of fine-tuning. Currently the most promising possibility for a ToE is string theory, but Stephen Hawking said: “Does string theory predict the state of the universe? The answer is that it does not.” In other words, string theory does not provide the physical necessity for the universal fine-tuning.
- Finally, even if the laws could be seen to inevitably lead to a hospitable universe, we are faced with the dilemmas of (i) how these laws could exist in the state of nothingness before the universe commenced, and (ii) how is it that the fundamental reality was like this. It doesn’t seem to make sense without God.
Thus Paul Davies concludes: “It seems, then, that the physical universe does not have to be the way it is; it could have been otherwise. and Lee Smolin says: It strains credulity to imagine that mathematical consistency could be the sole reason for the parameters.”
Premise 5 is considered to be virtually impossible by almost all cosmologists – the fineness of the tuning is immensely improbable by chance. The following quotes from eminent cosmologists show this:
“To make the first 119 decimal places of the vacuum energy zero is most certainly no accident.” Leonard Susskind (‘The Cosmic Landscape’)
“Perhaps before going further we should ask just how probable is it that a universe created by randomly choosing the parameters will contain stars. Given what we have already said, it is simple to estimate this probability. For those readers who are interested, the arithmetic is in the notes. The answer, in round numbers, comes to about one chance in 10^229.” Lee Smolin (‘Life of the Cosmos’)
“This now tells us how precise the Creator’s aim must have been: namely to an accuracy of one part in 10^10^123. This is an extraordinary figure.” Roger Penrose, former Professor of Mathematics at Oxford University and a cosmologist who worked with Stephen Hawking (‘The Emperor’s New Mind’)
Conclusion (proposition 6): The argument is logically valid and its premises seem more probably true than false. Thus it leads to the probable conclusion that our universe was designed. The argument stops there, but, when combined with other arguments, it is reasonable to conclude that the only possible designer is God.
Again there are many counter arguments, the most important being:
Premise 2: If the laws had been different, life would have evolved differently.
But even small changes to some of the constants make it unlikely even that stars or planets would form, or that any atoms other than hydrogen or perhaps helium (which are not enough to make anything nearly as complex as life) would form, or even that our universe would last long enough to allow life to form. Physicist Victor Stenger has constructed a computer model that shows that about half the possible universes would exist long enough to allow stars and planets to form. However the model is very simplistic and he doesn’t seem to have convinced any cosmologists.
Premise 3: The multiverse hypothesis is that our universe is part of a much larger universe (often called a multiverse) which has generated a large number of universes. If there were enough of these alternative universes, and if each one had different settings of the laws and constants, then eventually an inhabitable universe would be created and that is the one we find ourselves in.
Outlandish as this idea might appear at first, cosmologists believe it is consistent with current cosmological theory, even though other universes could never be observed. However the multiverse hypothesis doesn’t appear to be sufficent to throw doubt on Premise 3, because:
- Some cosmologists reject it as a scientific hypothesis because, it is believed, it can never be observed or verified.
- It requires that the multiverse be capable of generating billions of universes each with a different set of parameters. But, as Paul Davies has pointed out, such a multiverse would have to be fine-tuned to produce such an outcome, which simply brings us back to the same difficulty – is it this way by necessity, chance or design?
So it appears the same three possibilities remain even if the multiverse is considered to be possible.
Premise 4: It remains possible that science will one day find an underlying reason or law which makes the characteristics of our universe inevitable.
Despite the facts that (i) we don’t have this now, (ii) some cosmologists doubt we ever will, and (iii) it is hard to see how the ‘nothing’ out of which our universe appeared could have contained any laws, this remains a possibility. But the current interest of cosmologists in the multiverse throws this objection into serious doubt, because they all assume that each universe within the multiverse has different settings, and so are not fixed by physical necessity at all.
Premise 5: It is meaningless to talk about probability when we only have one known universe and no frequncy distribution of universe on which to make a judgment of probability.
But there are forms of statistics which can deal with this situation, and if we consider the set of all possible universes, a frequency distribution can be calculated. This was the approach used by Roger Penrose (Professor of Mathematics at Oxford University and clearly qualified to make a judgment on the validity of making statistical estimations of the probability of our present universe occurring by chance). And he is the one who made the probability estimate most often quoted.
The multiverse doesn’t help with the probability objection either. Currently string theory predicts that, if there is a multiverse, there would be 10^500 universes. This is an enormously large number, but only an infinitessimal fraction of Penrose’s estimate of probability. Even 10^500 universes don’t make our universe even remotely likely by chance.
Conclusion (proposition 6)
- We shouldn’t be surprised we live in a universe that supports life – we wouldn’t be here if it didn’t.
But this objection (sometimes named ‘the anthropic principle’) has been shown to be a logical fallacy. Of course, granted we are here, it must be true that our universe supports life. But how likely is it that we are here (i.e. out of all the possible universes, how many could support life?), and what is the explanation? Which ever way we look at it, the present situation is highly unlikely, and the design argument can legitimately ask for an explanation.
- Who designed the designer? If the universe requires an explanation, then so does God, and we have gained nothing.
But all scientific explanations have the same form, they explain one thing in terms of something else. If this objection was true, then all scientific explanations would be disallowed also. The truth is that every step backwards in an explanatory chain gains us knowledge. Then why stop at God? But we are not compelled to stop at God – it’s just that we seem unable to go further, and a logical place to stop (and so avoid an infinite regress) is at a ncessary being.
Again, this seems like a common sense argument. I think in this form it is even stronger than the cosmological argument. And again, the scientists don’t really have an explanation of these facts. You can read about the objections in more detail in The teleological argument, or read about the scientific facts behind the teleological argument in Science and the design of the universe.
Formal arguments and apologetics
I would guess most people don’t need to see formal ‘proofs’ of God’s existence. But having these clear in our minds can be very helpful for:
- Our own faith – sometimes when I have doubts, I think through the reasons why I believe (which includes these two arguments) to check whether I still think the reasons are true.
- Helping other christians with their doubts – they too may need reminding of why they believe.
- Answering the questions of non-believers – these arguments probably won’t even convince anyone who is committed to non-belief, but they may help more open-minded non-believers.
I believe these two arguments are strong reasons to believe in God. And not just some vague God, but a powerful, creative God who designed the universe for a purpose.