The 12 most popular reasoning failures (Part 1 of 2)

We all believe that we are rational in our decisions and our reasoning is flawless, calling the others that disagree with us ‘irrational’. Damned, if there is only one important thing I learned in my life, it is the fact that our brain is good at fooling us to believe we are rational when it is our animal instinct that is driving us.

Our animal brain hijacks our reasoning with argumentation that looks good at face value but is just nonsense. They are called logical fallacies. The most amazing thing is that it works to convince ourselves about our intellectual superiority but also to influence others because we have all the same defects originating from our biological ancestors through our genes. Nothing is more common than logical fallacies. You listen at a speech of a politician, they come by dozens.

In his book https://www.amazon.fr/Logically-Fallacious-Ultimate-Collection-Fallacies-ebook/dp/B00GU3H270/ref=la_B004G76EI0_1_1?s=books&ie=UTF8&qid=1454780872&sr=1-1, the philosopher Bo Bennett collected 300 logical fallacies.

In this article, I will present 12 fallacies that could our reasoning and that I believe are the most common. Learn to recognize them, to avoid them and to counter them whenever you hear them.

1.    Ad Hominem Attacks

This is one of the most despicable tactics of argumentation. This tactic works as follows: “Person A makes a claim X, Person B reacts that attacking person A, his past, his origin, etc. (all elements that have nothing to do with claim X), therefore Person B concludes claim X is false.”

Example: “Marc claims earth turns around the sun, Marc is a communist, therefore we should not trust this information on earth turning around the sun.” The fact Marc is a communist is irrelevant to the argument.

One extreme case of such a fallacy is “Reductio ad Hitlerum” consisting in trying to link an argument to the Nazi program to counter it. For example, Betsy Hartmann used in an interview in 2003 (https://www.hartford-hwp.com/archives/25b/027.html )  this fallacy to counter arguments used by ecologists: “And how the ideas of ecologists about invasive species—alien species as they are often called—sound so similar to anti-immigration rhetoric. Green themes like scarcity and purity and invasion and protection all have right-wing echoes. Hitler’s ideas about environmentalism came out of purity, after all.” This is not done.

Recommendation: Focus on logic and evidence, not on people background.

2.    Authority Worship – Appeal to Authority Fallacy

This logical fallacy is similar than an ad hominem attack but in opposite. Remember we are just evolved chimps with an obsession for social ranks and power.  A weak spot in our brain drives us to obey someone with appearance of authority. This fallacy looks as follows: “A very important person claims X is true. Therefore, claim X is true.”

Example: “Mr. Donuts claims earth is only 10,000 years old. Mr. Donuts has a PhD in Medieval Literature; therefore, his claims must be true.” Indeed, it is a good start but not good enough.

In short, do not let authority be confused with logic and argumentation.

3.    Appeal to Popularity Fallacy

Again we are social animals. We tend to consider as true the wisdom of the masses. Remember truth is never decided by vote: majority has been wrong so many times throughout history. This fallacy looks as follows: “Everybody is doing/telling X. Therefore, X must be the right thing to do/believe.”

Example: “A majority of the Scottish people believe in Loch Ness monster. Therefore, it must exist.”

In the Middle Age, all the Europeans believed that earth was the centre of the universe; and yet nothing was less true.

4.    Circular reasoning

This is very popular among religious people. This illogical reasoning works as follows: “Person A claims X is true because of Y. Then the same person claims Y is true because of X.”

Example: Religious person says: “Sacred Book is the Word of God”. Then the skeptical person says: “How do you know that?”. The religious person answers: “Because God tells it so in Sacred Book.”

My most amazing debate was with a doctor in Islamic studies who, in short, claimed that you need to believe what you believe in order to believe what you believe. Actually it is logically correct but not very convincing.

A similar fallacy is called “begging the question”. This is when the conclusion is already included in the premise: “Claim C assumes X is true. Therefore, claim X is true.” Example: “Opium induces sleep because it has a soporific quality.”

5.    The emotional potion

This is a tactic sometimes used by politicians and salespeople: make a statement that causes an emotional reaction that clouds our logical reasoning. There are many studies that demonstrate that emotions affect logical reasoning. Be aware when we are emotional, we are not good in reasoning; therefore, postpone any decision if you are in such a state.

6.    Straw-man fallacy

This fallacious tactic is also very popular in debates: this is to use a distorted, exaggerated, misrepresented version of the opponent’s argument to attack and mock it easily.

Example: “Person A claims that teens should be taught contraception methods so they can practice safe sex should they choose to have intercourse. Person B, using a straw man fallacy, responds proponents of sex education like Person A want to give kids license to have sex with no consequences.” The fact Person A is in favor of sex education for teens does not mean that he is a proponent of teens having sex together. Therefore, the argument of Person B is not only fallacious but also despicable.

Next week, I will post the next 6 most frequent reasoning failures.