Arguing from the Evidence: The Fine-Tuning Argument


The Universe that we live in is special. In fact, it is very, very special. Scientists are in awe of just how special this Universe appears to be. The apparent fine-tuning, or precise calibration, that we see in the Universe is quite simply amazing.

For the Christian, this all makes sense. For the non-believer this poses a problem. This, the second part in our ‘Arguing from the Evidence’ series, is the Fine-Tuning Argument.

Dialled In

Sir Martin Rees, our top Astronomer, wrote the book on the science behind this wonder. Just Six Numbers shows how our basic physical constants need to be dialled in to precisely the right setting for life to have come to exist after the Big Bang. A slight variation from this, and there would be nothing.

And the variation needed for change is slight indeed. Let’s take gravity for instance. Robin Collins tells us that if we change gravity by “one part in ten thousand billion, billion, billion” there would be “no humanly populated world”.

There is no ‘safe zone’, no happy band for which these settings can exist. They’re either right or they’re wrong, and there are billions and billions of other settings that are ‘wrong’.

The dial is set, and is set well for life. Either this is pure cosmic accident, chance, or something set the dial that way.

But when you look deeper into this, as scientists do, it gets harder and harder to believe that is luck. The odds just don’t stack up.

Sir Fred Hoyle, himself an atheist, honestly concludes that, “a common sense interpretation of the facts suggest that super intellect has monkeyed with physics … and that there are no blind forces worth speaking about in nature.”[1]

Alister McGrath sums up the findings of evidence this way: 

“The phenomenon of fine-tuning is widely conceded; all debates concern its interpretation.”[2]

So What?

As you read this perhaps you are thinking to yourself, “so what?” “I’m here, we’re here – does it really matter what the odds were? Even if the odds are strongly against this outcome – like the odds of an English fight-back in The Ashes – still, it could happen.”

Well, let me use an illustration at this point. You’re playing poker. You’re playing poker with your friends, after a couple of beers, the same thing you do every Sunday night. One night, one of your friends turns a Royal Flush in one hand.

Now you’re quite the poker guru. You fancy that if you were made unemployed it would be no big deal. You would be on the Pro-Poker circuit making much more money and having much more fun within days. So you know that the odds of your friend having those cards is 0.000154%.

But maybe it’s his lucky day, you surmise. But then he gets those cards again, and again, and again.

Common sense screams so loudly into each players mind that something is not right. This just can’t happen.

Sure, it could – but what are the odds! In the same way, the odds of the Universe arriving in this condition are so low that we should think twice about what this means.

What if …

Not everyone is led to believe in a divine intellect from the analysis of the data. Martin Rees himself, acknowledging the incredible facts, is not led to believe in God.

One theory, and one that Rees goes for, is that there are many universes, and we live in just one of them. If there are many universes – or perhaps an infinite number – then the odds are greater for life on one or many, or further still, expected.

Of course, actual infinities are tricky (something we looked at with the Kalam Cosmological Argument). Furthermore, even if we indulged in speculation on the idea of many Universes why should this one have the right conditions for life? It’s still a huge stroke of good fortune.

Following the Evidence

The noted philosopher Anthony Flew was led to change his mind, and back down from his strident atheism, in part due to the weight of the Fine-Tuning argument.

This remarkable, finely-tuned world that we live in prompts us to ask ‘Why?’ The data invites us to lay aside our preconceptions, our prejudices, our presuppositions, and consider the facts as neutrally as possible. When we do that, the case for a God takes on new weight, and far from being an intellectual cop-out, becomes a position of intellectual honesty.

Alvin Plantinga, one of the world’s leading philosophers, concludes that the evidence shown by the Fine-Tuning Argument ultimately makes more sense for Christians than for atheists:

“Given theism, fine-tuning is not at all improbable; given atheism it is; therefore theism is to be preferred to atheism.”[3]

The question now becomes, where will you let the data take you?

[1] Fred Hoyle, quoted in Douglas Groothius, Christian Apologetics

[2] Alister McGrath Mere Apologetics p. 99

[3] Alvin Plantinga Where The Conflict Really Lies p. 199