Monday, 7 September 2009
I expected that my 'truth is...' post would be more controversial. After all, we're willing to debate art vs science or the technicalities of evolution at length. Yet the bigger question of 'what is truth' led to one single response. Perhaps people found it boring or trivial and obvious. Not only is this not the case, but it's implications for how we think about the world are staggering.
I want to continue this series here by discussing the most commonly met objection - that a belief in science is no more justified than a belief in God.
Let's start with what is a belief and what justifies it?
In general let's define a belief as an idea that reality works a certain way.
We know from our understanding of truth that the correspondence to reality is all important as far as keeping our beliefs honest. Reality is a certain way and truth is how close our mental model is to reality. We test this difference via making a prediction of an outcome then observing how close what we measure is to what we predicted. This is the scientific method.
When it's stated this way it quickly becomes clear that the accuracy of a belief - it's correspondence with reality - can soon be tested. To understand the difference between the scientific way of thinking and the religious let's take two examples - I believe that gravity follows the inverse square law and I also might believe that when I pray God cures people (i don't but let's follow the argument that got me to my current position).
Let's design experiments to test these beliefs. To test gravity I might stand on top of a tower and drop a ball, timing how long it takes to fall. Then I can take a completely different situation where my theory still claims to apply. I can measure the distances and speeds of the planets in the solar system.
It's completely astounding that we can apply the same law to both these situations but that's what we predicted and, of supreme importance, it's what our experiments show us. Conclusion - it's an extremely accurate and general belief.
My belief that God cures people when I pray is also measurable. I get together two groups of people and pray for one. It's easy to observe that when i do this it makes very little difference whether the person was in the praying or non-praying group. Both group die and survive equally. Since this is in direct opposition to our predictions it leads us to conclude that it's an inaccurate belief*.
This is the crux of the debate. It's possible to label both the 'inverse square law of gravity' and 'prayer as healing' as beliefs but this linguistic trick does Newton a massive disservice. One is a belief that is supported by a huge amount of evidence. The other is a belief that is contradicted by all the available evidence. It's disingenuous to label both statements as beliefs because they correspond to very different approximations to the truth. Let's simply agree to label one as a fact** and the other as bullshit.
It's this correspondence to reality that allows us separate science and religion. Imagine an alien race from the opposite side of the galaxy - however different their anatomy, their society, their values and their religion, I guaran-DAMN-tee that they still know the inverse square law***. And that's got to count for something.
*People will try to weasel out of this conclusion in so many ways. If you immediately jump to try to find ways out for prayer, please think all the details through. Do you really think that I can control who God can and can't heal by choosing to monitor their survival outcomes?
**I realise that this implies that a fact is not a certainty and can be slightly inaccurate. But since we can never provably attain the complete truth, a prediction supported by a huge body of evidence is as close to 'fact' as we can ever get. So we may as well label it as such.
***I'm aware of general relativity. How science builds on itself is the next but one post in this series.