Surviving the Internet: Logical Fallacies Part 2

Our species has accumulated so many of these things. It’s downright amazing.

Again: not a logician, magician, or statistician. Just a guy with time on his hands.


Appeal to consequences

Structure: “If everyone believed there were nearly 7 billion people on the face of the Earth, some of them would become serial killers because they have so many targets. Thus, there are not nearly 7 billion people.”

Calculating the accuracy of a statement using the consequences you think it will have is like trying to calculate the weight of a car based on its colour. They’re just…not comparable.


Argument from verbosity

Structure: “[800 pages of rambling]. Therefore, Xenu exists.”

If you’ve said too much for anyone to ever actually read, a) you win automatically, and b) you really, really need to get a life. Those are the two fundamental premises of this one.


Begging the question

Structure: “Bill will back me up on this, and you know he’s trustworthy because I can vouch for him.”

It’s quite hard to pull off a proper question-beg. The first thing you need to do is come up with a premise that already assumes that what you are trying to argue is true. Then you need to run that premise through a neatly cyclic argument so that it ends up proving itself.


Chronological snobbery

Structure: “They believed sex made babies back when people thought the Earth was flat. Therefore, sex does not produce offspring.”

According to chronological snobbery arguments, when one thing believed at a time is wrong, it makes everything else believed at that time wrong simultaneously. The logical corollary is that everything that anyone has ever believed is wrong and we should just take up chainsaw juggling instead.


Exception proves the rule

Structure: “Life is good, apart from the groin beetles. They’re the exception that proves the rule.”

“The exception proves the rule” is easily the most misused phrase in human history, narrowly beating out “I’ll respect you in the morning” because the people using that one at least know that they don’t mean it. What it actually means is that if you see a sign saying “No starting fires during January”, you can infer from that exception that the rule is “you can start fires in any other month”.


Gambler’s fallacy

Structure: “I’ve rolled all the 1s out of this twenty-sider, thereby making it more likely to come up as 20.”


More seriously (and when I’m being serious things have gone downhill), the gambler’s fallacy is assuming that the relative probability of events remains the same no matter which stage you’re at. If a die has rolled multiple 1’s, this does not make it less likely to be 1 next time. (Indeed, it could indicate that the die is poorly balanced.) Likewise, a number of black results on a fair roulette wheel (not that any casino would use one) does not indicate that red is due for a run.


Ignoratio elenchi

Structure: “All dogs are animals. All terriers are dogs. Therefore, all terriers are animals. What do you mean, we were discussing werewolves?”

Ignoratio elenchi arguments tend to be robustly logical, internally consistent, and generally correct, but do not, in fact, address the point they were trying to refute.


Kettle logic

Structure: “I never borrowed your Xbox! I returned it undamaged! It was damaged when I borrowed it!”

The favoured tactic of Bart Simpson and anyone who’s ever panicked, a kettle logic approach consists of throwing multiple inconsistent positions at your opponent, then running away.


Misleading vividness

Structure: “[describes partial birth abortion in the most grotesque terms available], therefore we should ban abortion.”

The trick to making vividness misleading is to direct it at an extreme case and hope the more mundane and reasonable variants get caught in the blast radius. Then you describe that extreme case as convincingly as possible, and let it run from there.


Nirvana fallacy

Structure: “Your suggestion of going around the quicksand is good, but it doesn’t prevent us from getting stuff on our boots or tripping over rocks. Come up with something better.”

Ah, perfection. If you have no ability to produce it yourself but demand it from your underlings, you may be a middle manager. You may also be quite fond of the Nirvana fallacy, in which you reject good solutions for being imperfect. Well, yes, everything is imperfect, even chocolate.


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