One of the things that annoy one most is having a discussion with someone who doesn't follow the rules of logic. The most common error is arguing from the particular to the general instead of the other way round. Here are some more of the logical fallacies we encounter, with examples. Identifying them makes one feel better immediately!
GENERALIZING FROM SELF: I'm a liar. Therefore I don't believe what you're saying.
THE FEW ARE THE SAME AS THE WHOLE: Some Londoners are animal rights activists. Some Londoners wear fur coats. Therefore, all Londoners are hypocrites.
FAULTY CAUSE AND EFFECT: On the basis of my observations, wearing huge trousers makes you fat.
I AM THE WORLD: I don't listen to country music. Therefore, country music is not popular.
IGNORING EVERYTHING SCIENCE KNOWS ABOUT THE BRAIN: People choose to be obese/gay/alcoholic because they prefer the lifestyle.
ARGUMENT BY BIZARRE DEFINITION: He's not a criminal. He just does things that are against the law.
ANYTHING YOU DON'T UNDERSTAND IS EASY TO DO: If you have the right tools, how hard can it be to generate nuclear fission at home.
IGNORANCE OF STATISTICS: I'm putting ALL my money on the lottery this week because the jackpot is so big.
IGNORING THE DOWNSIDE RISK: I know that bungee jumping could kill me but it's three seconds of pure thrill.
SUBSTITUTING FAMOUS QUOTES FOR COMMON SENSE: Remember "all things come to those who wait." So don't bother looking for a job.
IRRELEVANT COMPARISONS: £100 is a good price for a toaster, compared with buying a Ferrari.
CIRCULAR REASONING: I'm correct because I'm smarter than you. And I must be smarter than you because I'm correct.
INCOMPLETENESS AS PROOF OF FACT Your theory of gravity doesn't address the question of why there are no unicorns, so it must be wrong.
IGNORING THE ADVICE OF EXPERTS WITHOUT GOOD REASON: Sure the experts say you shouldn't ride a bicycle in the eye of a hurricane, but I have my own theory.
FOLLOWING THE ADVICE OF KNOWN IDIOTS: Uncle Horace says eating pork makes you smarter. That's good enough for me.
REACHING BIZARRE CONCLUSIONS WITHOUT ANY INFORMATION: My car won't start. I'm certain the spark plugs have been stolen by rogue traffic wardens.
FAULTY PATTERN RECOGNITION: His last three wives were murdered mysteriously. I hope to be wife number four.
FAILURE TO RECOGNISE WHAT'S IMPORTANT: My house is on fire! Quick, call the post office and tell them to hold my mail!
OVERAPPLICATION OF OCCAM'S RAZOR: The simplest explanation for the moon landings is that they were hoaxes.
INABILITY TO UNDERSTAND THAT SOME THINGS HAVE MULTIPLE CAUSES: The Beatles were popular for one reason only: they were good singers.
JUDGING THE WHOLE BY ONE OF ITS CHARACTERISTICS: The sun causes sunburns. Therefore the planet would be better off without the sun.
BLINDING FLASHES OF THE OBVIOUS: If everyone had more money, we could eliminate poverty.
BLAMING THE TOOL: I bought an encyclopedia but I'm still stupid.
TAKING THINGS TO THEIR ILLOGICAL CONCLUSION: If you let your barber cut your hair, they next thing you know he'll be lopping your limbs off.
PROOF BY LACK OF EVIDENCE: I've never seen you drunk, so you must be one of those weird people.
BAD ANALOGY: You can train a dog to fetch a stick. Therefore, you can train a cat to do the same.
TOTAL LOGICAL DISCONNECTION: I enjoy pasta because my house is made of bricks.
Also frequently misunderstood:
CORRELATION DOES NOT IMPLY CAUSATION in science and statistics emphasizes that correlation between two variables does not automatically imply that one causes the other.
The opposite belief, correlation proves causation, is a logical fallacy by which two events that occur together are claimed to have a cause-and-effect relationship. The fallacy is also known as cum hoc ergo propter hoc (Latin for "with this, therefore because of this") and false cause. By contrast, the fallacy post hoc ergo propter hoc requires that one event occur before the other and so may be considered a type of cum hoc fallacy.
A wonderful illustrated guide to Bad Arguments here
