I have gone for the latter, as it seems to work quite well – the idea came to me during the recent Human Fertilisation and Embryology Bill which included debates on the use of animal-human hybrid embryos, Saviour Siblings, and lowering the time limit for abortions. DrAUST has written a comprehensive and sensible blog post on this issue, so no need to duplicate it all here.
What I wanted to blog was a brief summary of some of the tactics used to cloud debate, how to spot them and more importantly, how to deal with them.
(Incidentally, I should point out that there are undoubtedly more than 5, and indeed they may or may not begin with A, but the ones below are the main ones and will hopefully prove useful)
1. Argument from Authority
A real favourite for the Complementary and Alternative ‘medicine’ people. You can read the full silly story of lame homeopathic warrior Dana Ullman, insisting that Charles Darwin was an advocate of homeopathy.
Even if he was (he wasn’t) he’d have been wrong - it would add no value at all to the argument. Famous people are not infallible; because they were very clever about one area doesn’t mean they are knowledgeable about all.
2. Argument from Anecdote
“My sister often suffered from…… but since……”
Again, a classic (s)CAM argument – religious ‘miracles’ are also perpetuated this way.
This gives no idea as to confounding factors, people’s selective memories, story telling mistakes, mis-interpreted results etc etc. Humans are terribly prone to bias, which is why the gold standard for clinical trials is a randomised,double-blind, placebo-controlled, multi-centre trial. Also, from a statistical point of view, it may be pure chance, unless you have a handle on the numbers of people in the same position (the ‘n’ number). Derren Brown’s The System shown on Channel 4 in Feb 2008 is an excellent demonstration - a good overview is here.
3. Argument by Appeal to Emotion
I had a different example for this but MP Edward Leigh’s emotive nonsense in the Human Fertilisation and Embryology bill debate discussing human-animal hybrid embryos, takes some beating
If an embryo could talk, perhaps they would echo what Mary Shelley wrote in “Frankenstein”:
“I, the miserable and the abandoned, am an abortion, to be spurned at, and kicked, and trampled on."
OK. The embryo can’t talk. End of argument. This is pure appeal to emotion, carries no weight of evidence and in my view, demonstrates Mr Leigh’s poor debating technique.
If my coffee cup could talk perhaps it would say “I, the miserable stained cup made to endure boiling water……”. Nonsense.
4. Argument from the Alternative
This is trying to give weight to an argument by attempting to show that the alternative is not preferable. It may be a relevant point, but it doesn’t provide any evidence for what is being argued for. The textbook (and frequently trotted out) example of this is:
“There must be a God, otherwise there would be no point to life” – answer – why must there be a point to life, apart from you feel there should be one?
Regardless of the argument in point, arguing that the alternative is preferable is not evidence for the opposite. (For another example see Anonymous comment on the blog post regarding double-blind, placebo controlled trials – not only argument for the alternative, but argument from …em…. being wrong.
5. Argument by Ad hominem
Ad hominem is latin for ‘to the man’, but its meaning in debating circles is to use (irrelevant and often untrue) character slight as a means of winning an debate. Again, the homeopaths especially like to use this one - if you take them to task about the lack of evidence that exists for their quackery, you will often be portrayed as a ‘big Pharma shill’ with no independent thought. Again, even if it is true (it isn’t) it doesn’t change the fact that homeopathy (and other CAM techniques) are quackery and have no solid evidence of efficacy. The person making the statement of fact has no bearing on the veracity of the fact.
So there you have it. The Five A’s of Empty Argument – now, where is my book deal and whirlwind world tour?
(Post more below, but please try and make them begin with A or else we won't get anywhere :)
ETA - There is a prize of an internet to anyone who can find all five being used in the same place (sCAM fora, blog posts, etc).
Obviously this blog doesn't count.....
EDIT (18/06/08): Thanks to Nash for giving the 6th 'A' - Argument from Antiquity. Many CAM-type rationales (and religious reasonings) come from the thought that "it has been done for hundreds/thousands of years". It well have a long history, but it may also have been wrong as well.
EDIT (03/07/08): Seven seems a much better number that 6 or even 5, and so, thanks to Deano over at BadScience for adding "Argument by Analogy" to the list. Something along the lines of
"When steam builds up in a steam engine, it needs to be let out.
Emotions build in people just like steam builds up in steam engines.
Therefore, emotions need to be let out."
Keep them coming!