Evidence – How To Change My Mind

Let’s take something that is quite obviously a load of rubbish: Homoeopathy. I will now state the following:

Homoeopathy does not work

My reasoning for homoeopathy goes as follows:

  • Implausible (there is no prior plausibility that suggests HOW it should work)
  • No good scientific evidence to show it works

I want to make the following clear:

I would love for homoeopathy to work. It would revolutionise medicine and curing people and it would also create whole new areas of physics for us to learn about.

However, the evidence does not show it works. The gold standard of medical trials, double blind random controlled, all show negative. See my “discussion“.

If you can show me the evidence and it needs to be good evidence then I would be willing to change my mind. I will shout it from the rooftops and I will become your cheerleader. I will work tirelessly for your cause because it would be so wonderful.

If you can show me the evidence I will change my mind.

I think that’s quite a simple rule to live by. It does mean I have to be able to evaluate the quality of evidence and I could make mistakes there, but I am willing to correct myself.

If what you are suggesting is a quite remarkable “new thing” then the evidence needs to also be quite remarkable to persuade me. If what you are suggesting adds to my current understanding then it will take a normal amount evidence. This is not to say I am closed minded. I would love to be wrong about many of the things I currently know are not true. It would be a brilliant and happy thing to be shown good evidence for something you say is true. As I mentioned earlier I would happily change my mind. Here’s a list of types of evidence ranging from very bad to good:

  • Anecdote [NOT evidence. NOT even interesting]
  • Testimony [NOT evidence. Human memory is remarkably poor at recalling what happened]
  • Human Experience [NOT evidence. We can only explain the world within our understanding]
  • A single experiment or non-blinded medical trial [an interesting start but NOT fact]
  • Results of single experiment reproduced by teams working separately [Good evidence]
  • A medical trial which is controlled [still more interesting]
  • Results of different reproducible experiments leading to same conclusion [this can go in stone]
  • Results of large scale double-blinded placebo controlled medical trial NOT paid for by pharmaceutical company [expect the results to lower efficacy a bit over time but this is a good treatment]

The wonderful thing about this process of requiring evidence, oh I know, let’s call it the scientific method, is that it does not rely on me believing. The truth is there whether I believe it or not. A scientist working in Japan should come to the same conclusions as a scientist working in Brazil. The scientific method leads us to knowledge whatever our social and cultural background.

A good place to start when faced with something you understand to be quite fanciful is to ask for the VERY BEST evidence for the thing. If this is poor, then walk away. Do NOT accept the following argument:

Oh, the effects are subtle and can’t be measured.

If the effects are that subtle that they can’t be measured by scientific means then they don’t exist. We observe our world and we do our best to understand it and measure it. If you can’t measure it then it deserves to be rubbished. Just because someone believes it dearly it doesn’t mean it’s any more true. Aren’t we doing them an injustice by not educating them?