The teleological argument is one of the oldest and most popular arguments for the existence of God. The World, claim its proponents, is an amazing place full of such complicated, intricate and clearly therefore designed things, that there must be a designer. If you find a rock on the floor, it would be safe to assume that it had just spontaneously appeared, and had been lying around being a rock pretty much forever; if you found a watch, however, it would be rash to presume it that it formed without some intelligent assistance. The same is true of the perfect ecosystem of Earth and the human beings at its pinnacle. Someone must have made it all. That someone is God.
A rethink of this position was forced with the advent of evolutionary theory. Almost all scientists now consider evolution an adequate explanation of how ordered complexity can arise from disordered rubbish, so instead of postulating that life itself was amazing, it was necessary instead to make the fact that the Universe has conditions appropriate for evolution to occur the unlikely, and thus God-requiring, stage.
This could well be fair enough. There are plenty of ‘fundamental constants’, as they are called, which, were they a tiny bit different, would not allow life to occur. A favourite is the so-called fine structure constant, α, which is a measure of the strength of the electromagnetic interaction. It is actually defined as the speed of an electron orbiting in a hydrogen atom divided by the speed of light, and this is what makes it appealing: it is a speed divided by a speed, so whatever units you choose, the answer will be the same number. Its value is 0.00729735…, more often written as 1/137.
Now, changing this by a fraction could mean that atoms were no longer bound together, an obvious disaster for life as we know it, or it could mean that the nuclear fusion which powers the Sun zips along a little too fast and life wouldn’t have time to evolve. In fact, changing it by anywhere from a small to a huge amount could have all manner of drastic repercussions at every scale in the Universe. Some bizarre form of life might be able to evolve, but it’s more likely that none would emerge at all. So why has it got that exact, rather convenient value?
There are tens of physical constants to which a similar logic can be applied. Knock the strength of gravity, alter how big the Big Bang was, change how much matter there is in the Universe or make the strong nuclear force a little less strong, and the chain of inevitable changes to the laws of physics would make any life untenable.
So, the chances of a life-supporting universe arising randomly are pretty slim.
Consider, on the other hand, the chances of life arising if there is a God who, for some reason, desires life. We need not question the nature of Him or His motives for the moment, merely that he wants life, and is capable of making a universe which can sustain it. What are the chances of life under this new regime? Unless he’s pretty cack-handed, close to one.
Say you told me that you had a coin with a one on one side and a six on the other and a six-sided die, and then told me that by either rolling the die or tossing the coin, you had just obtained a six. As a betting man I would put my money on you having used the coin to get that six, because fifty-fifty is much more to my taste than a meagre seventeen percent.
Scaling up the analogy, we have a one-sided coin (the pretty much certainty of life arising in a universe created by a life-loving God) versus a die with more sides than the human imagination can conceive, one for every single universe which can’t sustain life.
Therefore, to a pretty good approximation, God exists. Or rather, the probability of our having been created by something other than a life-desiring God is so small that it cannot be conceived by the human imagination.
Is there any further reason to be sceptical about God’s existence, beyond that inconceivably small fragment of possibility that he doesn’t?
Unfortunately, yes. The problem is that applying probabilistic arguments in this case is pretty much meaningless, because we have no idea what the likelihood of the options enumerated above really is.
To return to my coin and die, guessing the coin is all very well, unless you’re a running a scam and only ever use the die. Despite it being more likely to be the coin if you choose which to use at random, using each one half of the time, you don’t have to use the coin much less often for it to start becoming favourable to guess the die. Thus, if God’s existence is impossible or unlikely by a similar amount to a life-friendly universe arising by pure chance, the playing field starts to be levelled somewhat.
The other problem with this argument is that it is somewhat philosophically unsatisfying. All you know if you believe the probabilistic interpretation is that there is a God who likes creating life, and you have no idea of any other characteristics of His, from omnibenevolence to even his continued existence to this day.
So, the God versus atheism battle persists unresolved…but the teleological argument is strangely compelling, don’t you think?