Of Rationality, Engineering and Faith

On Sunday I joined the audience for “The Big Questions”, a BBC2 debate filmed in York to be broadcast Sun 4th May at 10am. I listened to a range of speakers (including author Alastair McGrath, who was sitting in front of me) on the question, “Is it rational to believe in God?”

This got me thinking that in matters of both faith and engineering, reason can only take you so far, because there are limits to what we can know. Every day I try to apply scientific principles to model how a structure or slope will work, based on the evidence I have been able to obtain. But can we ever truly predict the loads that will be applied to a structure or the worst credible weather event that might occur? And performance will be significantly affected by how people actually use or maintain the structure over its 120 year design life, which might be completely different to what we expect (could the Victorians have predicted the rise of the motor car?)
So I keep butting up against the reality that our models are only a crude approximation to reality and we will never have the complete picture: if we waited until we understood everything to the last detail, nothing would ever get built!

As engineers, we have a solution to this problem. It’s called engineering judgement, and we are deemed competent (eg in the chartered professional review) if we can demonstrate that we have learned to apply our own experience and the collected wisdom of those who went before us captured in textbooks, design codes and wise old engineers. We have learned from failure and from the performance of old structures built 100 years ago, so we can then apply this to modify our expectations of how well things tend to work in the non-ideal world we live in. Often this means applying a “factor of safety” or a sense of “given that I know how this data was obtained and the difficulty in getting a reliable result when drilling holes in the pouring rain, how big a pinch of salt should I apply to these test results?”

As a Christian, I apply the same process to my faith. My faith in God started with a rational examination of the evidence: for example, I am convinced that Jesus rose from the dead because the other available explanations seem very unlikely – why would the disciples go from terrified people who just saw their friend and leader killed to boldly telling the world that Jesus was in fact alive, and then being persecuted and even killed for saying this if they knew it wasn’t true? And if the Romans or the Jewish leaders had stolen the body, why didn’t they produce it as counter-evidence when his disciples started saying Jesus was alive?

But as in engineering, I have found that reason is a good place to start (you need to ensure you’re going in the right direction) but if that’s all you’ve got, you’ll never build anything! A faith based only on argument is lifeless and dull, but my faith is based also on “engineering judgement” – my own personal experience of deep relationship with a God who wants to engage with his world, and the collected wisdom of all who have enjoyed this relationship within the church and written down in the Bible.
See also:
Why Tread Lightly?
Advent Reflections 2014