In the film Contact, the scientist Ellie Arroway who discovers the ETI signal (played by Jodie Foster) is an atheist/agnostic who has a romantic relationship with a theologian Palmer Joss (played by Mathew McConaughey). The film’s creators were clearly trying to strike a middle ground between these two competing views, presumably to not alienate any potential audience segment. So they tried to soften the agnostic implications of the novel by trying to find a way to put religious beliefs on a par with science. To do so, the film essentially resurrects the convenient (but dubious) argument that science deals with the physical world while religion deals with the spiritual world.

In one scene, Arroway explains to Joss why she does not believe in god. She says it is because there is no evidence of his existence. At that point, he asks her whether she is certain that she loves her late father and she says she does. Then he asks her to prove it. Of course she can’t and he looks triumphant, as if he had made a brilliant insight.

I hear this argument a lot and it frankly puzzles me. As a justification for believing in god it makes no sense at all. The argument seems designed to make the point that there are things that are real whose existence we cannot prove and that god is of this nature. But as a justification for believing in god, it is silly. The fact that the smart scientist Arroway does not promptly destroy Joss’s argument shows how far the filmmakers were trying to strike a middle ground between belief and non-belief.

I think of ‘love’ as the label we give to a complex mix of physiological and neurological phenomena that occur in our bodies and brains as a result of particular kinds of interactions that we have with other people in specific emotional contexts. So it is ‘real’ in the same way that other emotions like anger, pride, sadness, etc. are real. We can relate the emotion to actual physical phenomena.

But why is this an argument for the reality of god? All it implies is that when we talk about ‘belief in god,’ all we are saying is that it too is just a label we give to a ‘complex mix of physiological and neurological phenomena that occur in our bodies and brains as a result of particular kinds of interactions that we have in specific emotional contexts.’ If this is what people mean by believing in god, then I would agree with it. After all, there is no doubt that when people experience something they like to call ‘spiritual’, there will be some corresponding physiological changes in their bodies, as there is for any emotion.

But we cannot extend this to assert that just because our bodies experience a real physiological change due to a belief, that therefore the thing we believe in has a reality and existence apart from us. Just because belief in god is a real experience does not mean that god is real. It would be like arguing that the love (or whatever emotion) I feel for someone or something, because it is real to me, therefore also exists independently of me.

POST SCRIPT: Common single blue-eyed ancestor

The idea of descent with modification is central to Darwinian evolution, and it implies that as we go back in time we can expect to find common ancestors (sometimes just a single one) in which some feature originally appeared. This feature can grow in the population and spread even if it provides no specific survival advantage. But its rate of growth is much slower than if it had even a small selective advantage.

Machines Like Us reports on how researchers have concluded that the blue-eyes that some people have can be traced back to a mutation that occurred in a single ancestor who lived 6,000 to 10,000 years ago.

The mutation of brown eyes to blue represents neither a positive nor a negative mutation. It is one of several mutations such as hair colour, baldness, freckles and beauty spots, which neither increases nor reduces a human’s chance of survival. As Professor Eiberg says, “it simply shows that nature is constantly shuffling the human genome, creating a genetic cocktail of human chromosomes and trying out different changes as it does so.”