Navigating the information world today has become somewhat of a daunting task. The internet allowed information to spread like wild fire and not all of it is what it seems. A lot of lies wrapped up with some truth, agendas promulgated and even trolls just trying to get an emotional rise out of their next group of victims. How does one orient themselves in this sea?
One tool for discerning of information is that of the logical fallacy. A fallacy is pretty much faulty reasoning in the construction of an argument, so logical fallacies are errors in that reasoning that end up invalidating the entire argument. Fallacies can be committed intentionally to manipulate or persuade by deception, as well as general carelessness or ignorance on a given topic.
As we can see with this language-independent fallacy:
1. "James is different from Bob."
2. "Bob is a man."
3. "Therefore, James is different from a man."
We're making the statement that Bob is different from James. Then somehow making a logical leap to say that because James is different from Bob, James can't be a man.
Another example would be:
1. "Basket ball players are tall."
2. "Playing basket ball makes you tall."
This was probably the first logical fallacy I was introduced to and been rather simplistic I think it's a good one to see how this can be applied further. If you can't already tell, we're making a selection bias and presuming an outcome, when all basket ball players are chosen for their height.
Fallacies have been around for a long time but the first systematic study we are aware of begun with Aristotle's work, De Sophisticis Elenchis (Sophistical Refutations). Very much worth a read for anyone interested to discover more about logical fallacies.
So, what types of logical fallacies exist?
Probably the most used logical fallacy and is basically exaggerating, misrepresenting, or just completely fabricating someone's argument.
Example: John said we should put more money into health services, Carlos responded by saying John hates our country so much that he wants to leave us defenceless by cutting military spending.
This is our basketball example from above. It's when we presumed that a real or perceived relationship between things means that one causes the other. This is shown a lot in statistics where correlation doesn't equal causation. Sometimes these things are entirely coincidental or may be down to a common cause.
Example: Imagine for a second, we have a fancy chart. Showing an increase in global temperatures and a decrease in global pirate activity. We can easily assume from this that pirates cool the earth and their decline is the cause of global warming.
Appeal to Emotion
This I saw a lot during our local elections in the UK, consistently repeating the rhetoric "Think of the children".
An attempt is made to manipulate an emotional response in place of a valid or compelling argument. Arguments may illicit an emotional response but the fallacy occurs when emotion is used instead of a logical argument, or to obscure the fact that there is no compelling rational reason for the position taken. These are all very effective argumentative tactic's that are completely dishonest. We are all emotional beings bar psychopaths so creating an emotional response becomes an easy task.
Example: Gillian didn't much like eating her vegetables but her mother told her to think about the poor, starving children in a third world country.
A presumption is made over a claim that has been poorly argued or a fallacy has been used, so the claim itself must surely be wrong. A claim may be logically coherent but false or vice versa true but not logically coherent with poor arguments.
Example: Discovering Charles' fallacy in his argument of eating healthy food, just because his nutritionist said he should, Carl said we should eat Ice-cream and snickers every day for breakfast.
A criticism is responded with criticism taking the heat off the accuser. Pronounced Too-Kwo-Kwee it literally translates to 'you too' and is a complete red herring and appeal to hypocrisy. This puts the accuser into the clear and puts the focus back on the person making the original criticism.
Example: George had identified that Charles had committed a logical fallacy, but instead of addressing the substance of his claim, Charles accused George of committing a fallacy earlier in the conversation.
When something requires some previous awareness or knowledge making it difficult to understand, a person would make out like it's probably not true. Complex subjects will always require some amount of understanding before one is able to make an informed judgement about the subject at hand. The fallacy happens because one just dismisses the subject without gaining that understanding.
Example: Bill drew a picture of a chimp and a human to show how evolution may have progressed for us. Richard suggested we were really stupid to believe that a monkey turned into a human just through random things happening over time.
An appeal is made to popularity or the fact that many people do something as an attempt to validate a claim. The flaw comes in this argument because just as many people do one thing, that does not validate the argument they are making. It would be like the earth making itself flat just to validate the flat-earth theory.
Example: Gillian had asked George to explain how so many people could believe in leprechauns if they're only some silly old superstition. George looked very perplexedly over his pint and nearly fell from his stool.
These are just a few of the many, many logical fallacies out there. They are worth learning and trying to apply to yourself and others. This is some kind of intellectual kung-fu, the vital art of self-defence during a debate.
Most fallacies fall under one of these four categories: Fallacies of Relevance, Component Fallacies, Fallacies of Ambiguity and Fallacies of Omission.
There is also Occam's Razor which is another useful tool in logical reasoning formed from logical fallacies. The original Latin "non sunt multiplicanda entia praeter necessitatem" basically means "don't multiply the agents in a theory beyond what's necessary." This means if two competing theories explain a single phenomenon, and they both generally reach the same conclusion whilst been equally persuasive and convincing then the logician should always pick the less complex one.
An example to help illustrate this would be someone coming home from work to find their dog has vanished from their garden. Now the dog could very well have vanished into thin air, been a teleporting dog an all. It's probably more likely though that the dog just escaped because of the faulty latch on the gate and isn't some canine superhero.