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Kat's note: I'm looking forward to talking about this on air in a few weeks!]
Coming out of my kitchen cupboard at the moment is a terrible smell. A miasma of rotting potatoes threatening to inflict upon me some awful disease. At least, that’s what I might think if I believed the old theory that foul smells could spread disease.
Now we could all chuckle, thinking patronising thoughts about how quaint it is for anybody to believe such a thing. We know that infection is caused by microbes, and the only way a smell is going to make you sick is if it were a disusting pile of…..(insert description here). We might feel a bit nauseous but we’re not going to conract Yellow Fever from a smell.
Still, you can see the logic. I went to a swamp. Thick gloopy anerobic mud, and it smelled disgusting. Next week I fell sick. Ergo the smell infected me with Yellow Fever. Here we have an example of false logic, which is what I want to talk about in this blog story.
You know what’s missing in the story above. The smell is associated with the swamp, but I forgot to mention the mosquitos.
Scratch, scratch, scratch, yourself
Life is really rotten
Especially with mosquitos there
To bite you on the bottom
Aristotle might’ve known about Yellow Fever, but he’s very unlikely to have known of its connection to mosquitos. He probably wasn’t much chop on disease, but he sure knew about logic, and when I invent my time machine and go to visit him, and to this story he will undoubtedly say non causa pro causa. Actually he wouldn’t because he was Greek, so please just use your imagination.
This is a case of The Fallacy of False Cause. A variant is reductio ad absurdum, which literally means “reduce to absurdity”. As a distinctly non-muscly kind of bloke I’m happy to give you an example of this. A body builder might say if some muscle is good, then lots of muscle must be really good. In fact, if I bound myself up in so many layers of muscle that I can hardly move, I must be the pinacle of human health. Yet you may have heard of body builders so focused on muscle development aided by steriods and diet restrictions, they die of heart failure.
My other favourite story is of a weapon called the “Mini Gun”. You’ve probably seen that (muscle man) Arnie swinging one of these around laying waste to aliens and bad people. It’s a water cooled gatling gun flinging out 6,000 bullets a second. Great for big time movie street cred, great for councelling people not like us, but not so good for winning the hearts and minds of people on the receiving end. If a few bullets are good for winning a war, then lots of bullets must be extremely good, but apparently not good enough to win the Vietnam war.
Meanwhile, Aristotle has been scratching out on parchment a catalogue of the forms of false logic. Some wag titled this his Sophistic Refutations, probably in the hope of making it sound impressive for publication. Here’s my interpretation.
The General to the Particular
Violent spectators have been a problem at English soccer matches, therefore English soccer fans are hooligans.
The Particular to the General
People find football entertaining, therefore I find football entertaining.
Irrelevent Conclusion
There are a few variants of this, but they all revolve around unrelated causes: Ad Hominem, against the man; Ad Misericordiam, an appeal to pity; Ad Populem, most people say..; Ad Vericumdiam, an appeal to authority – Rod says…; Ad Ignorantiam, in the absence of evidence; Ad Baculum, agree with me or else.
Circular Argument
Paula is bad because she is racist. She’s racist because she’s bad.
Many Questions
Have you stopped beating your wife? Is actually two questions posing as one.
False Cause
The miasma theory of disease.
Non Sequitur
Sue is wrong, therefore Bill must be right. Actually they’re both wrong. Rod is probably right.
By this time you might be wondering why I would be prattling on about philosophy on a science blog. Strictly speaking the Sophistic Refutations are about formal logic, which leaves no room for intuition or judgement based balance of probability. Circumstantial evidence is not permitted.
Science, on the other hand is based on evidence, and pure logic is not enough. I cannot simply don a robotic Dr Spock voice and make grand pronouncements on cold logic alone. Interestingly this is what our Greek friend did when he said things such as that the Sun revolved around the Earth.
In other words, in science you need logic and evidence, and this Sophistic stuff gives you a clue to the traps to avoid when drawing conclusions. Science had to invent methods to overcome the little logic traps nature sets for us. Deep breath, here’s one – smoking.
I remember great aunt Betty’s withered hand holding a Capstan cigarette, but did that kill her? Or perhaps it was he old age. Or because she had polio. To say with a confidence that A causes B, you need to control all the vairiables. But Betty objected to being stuffed into a test tube, so we have to use statistics instead and say that on the balance of probabilities, we think smoking is a cause of early death.
Ultimately this story comes down to a question of what is inherently knowable. I don’t know that logic will solve this problem, but I do know that without it we are left with a smelly miasma of diseased science.
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