Deep within humanity lies a longing to make sense of things. Why are we here? What is life all about? These questions are as old as the human race. So how are we to answer them? Can they be answered at all? Might God be part of the answer?

Richard Dawkins, England’s grumpiest atheist, has a wonderfully brash way of dealing with this. Here’s how science would sort out this muddleheaded way of thinking: everyone else just needs to get out of the way, and let the real scientists, like himself, get to work. They would have these questions sorted out in no time. His swashbuckling The God Delusion sweeps to one side “dyed-in-the-wool faith-heads”, who are “immune to argument”. Belief in God is just for those who are mad, bad or sad. Science has all the answers — and God isn’t even on the short-list. Only science-hating idiots think otherwise. End of discussion.

For Dawkins, things are dazzlingly simple. There is a cosmic battle taking place between reason (represented by science) and superstition (represented by religion). Only one can win — and it’s got to be reason. Scientists who profess religious belief are appeasers, representing the “Neville Chamberlain” school. You can’t be reasonable and religious. It’s one or the other — science or faith in God. Scientists who believe in God are therefore fifth column-ists, traitors either to science or religion.

This quick fix is ideal for those who like glossy, superficial spins on complex questions. But in the real world, things turn out not to be quite that simple. Two other interesting books appeared in the same year as Dawkins’s. Owen Gingerich, Harvard University’s distinguished astronomer, published God’s Universe. Francis Collins, director of the Human Genome Project, brought out The Language of God. Both these scientists, with a long track record of peer-reviewed publications, made the case for belief in God as the best and most satisfying explanation of the way things are.

So what are we to make of this? Perhaps Gingerich and Collins aren’t real scientists at all. Maybe they are manipulative religious charlatans who are just pretending to be scientists to garner support for their mad ideas. Or they might be well-meaning people who have been deluded into belief by that bullying “psychotic delinquent” (that’s Dawkins-speak for God, by the way). These answers might persuade some “dyed-in-the-wool faith-heads” of the atheist variety. But most thinking people, atheist or otherwise, will regard them as highly implausible. It is worth reminding ourselves that the hallmark of intelligence is not whether one believes in God or not, but the quality of the processes that underlie one’s beliefs.

So why are things not as simple as Dawkins wants us to believe? The beginnings of an answer are to be found in a wise book written back in 1987 by Sir Peter Medawar, who won the Nobel Prize for Medicine for his work on immunobi-ology. In The Limits of Science, Medawar reflected on how science, despite being “the most successful enterprise human beings have ever engaged upon”, had limits to its scope. Science is superb when it comes to showing that the chemical formula for water is H2O. Or, more significantly, that DNA has a double helix.

But what of that greater question: what’s life all about? This, and others like it, Medawar insisted, were “questions that science cannot answer, and that no conceivable advance of science would empower it to answer”. They could not be dismissed as “nonquestions or pseudoquestions such as only simpletons ask and only charlatans profess to be able to answer”. This is not to criticise science, but simply to calibrate its capacities.

This deft analysis by a self-confessed rationalist casts light on why scientists hold such a variety of religious beliefs. It makes it clear that scientists are intellectually and morally free to believe (or disbelieve) in God, while at the same time challenging religions to take the findings of science seriously. It also shows that it makes little sense to talk about “proof” of a world view, whether Christian or atheist. In the end, as Gilbert Harman pointed out decades ago, the real question is which offers the “best explanation” of things. And as there is no general agreement on how to decide which of these explanations is the “best”, the argument seems certain to run.

Christians will argue that their world view represents a superb way of making sense of things, while accepting that this, like its atheist counterparts, is open to challenge by sceptics. “I believe in Christianity as I believe that the Sun has risen — not only because I see it, but because by it, I see everything else,” wrote C. S. Lewis.

They know that they can’t prove that God is there, any more than an atheist can prove that there is no God. The simple fact is that all of us, whether Christians or atheists, base our lives on at least some fundamental beliefs that we know we cannot prove, but nevertheless believe to be reliable and significant. We all need to examine our beliefs — especially if we are naive enough to think that we don’t have any in the first place. It’s one of the best antidotes against the ideological fanaticism that The God Delusion manages to deride and represent at one and the same time.

Alister McGrath is Professor of Historical Theology at Oxford University. His book The Dawkins Delusion? Atheist Fundamentalism and the Denial of the Divine, written with Joanna Collicutt McGrath, is published by SPCK at £7.99