Reading Time: 5 Minutes

list of most common logical fallacies explained

Before going to the actual list of most common logical fallacies, let’s take a closer look at what an argument actually is. An argument is an attempt to convince. It’s a set of reasons that someone presents in order to convince another party to accept a certain idea or belief.

Similar to a chess game where each player must follow a set of rules, a good argument must adhere to certain principles of logic. However, when the argument violates these basic principles of logic, it is considered to be fallacious. The reasoning error’s in the argument is what’s called a logical fallacy.

In other words, a logical fallacy is a bad argument.

This article will examine the numerous ways that one can make a bad argument by highlighting the most common logical fallacies. Each of the fallacies that have been listed contains a brief description along with details about its structure as well as examples. 

#1  Fallacy of Division

The fallacy of division involves incorrectly assuming that if something is true for the whole, then it must also be true for its parts.

 

Whole X has property A

Therefore, each part of X has property A

 

Example: “If this bucket of sand is heavy, then it follows that each grain of sand in the bucket must also be heavy.”

 

#2 Fallacy of Composition

This is the opposite of the Fallacy of Division. It’s the incorrect assumption that because something is true for the parts, then it must also be true for the whole.

 

Whole X has property A

Therefore, each part of X has property A

 

Example: “If three players from my football team are great, then it follows that every member of my team must also be great.”

 

#3 Appeal to Nature

This is when the arguer asserts that because something is ‘natural,’ it is must be good or correct and vice versa.

 

X is natural     

         Therefore, X is good.

 

Example: “Don’t take those pills, they’re full of chemicals and are bad for you. Here, why don’t you try these nightshades, they’re natural!”

 

#4 Appeal to Tradition

Assuming that because something has been done a particular way in the past, that it is true or better.

 

X has always been done this way

         Therefore, X is better

 

Example. “We’ve been using this same recipe for the last three generations, why change it now?”

 

#5 Personal Incredulity

This fallacy occurs when an individual refuses to accept a claim because it contradicts their beliefs or expectations. In other words, the person has trouble ‘entertaining the thought.’

 

I can’t imagine claim X

         Therefore, claim X is false.

 

Example: “I can’t get my head around the idea that our planet is rotating around some mysterious axis. I just don’t buy it!”

 

#6 Ad Hominem

In Latin, Ad Hominem means ‘to the man,’ A person commits this fallacy when instead of challenging the argument itself, they attack the individual making the argument, pointing to their character flaws so as to undermine their position.

Out of all the fallacies mentioned in this list, the Ad Hominem fallacy would arguably be the most common logical fallacy that you’ll observe in debates, especially in political discussions.

 

Person A claims X

But Person A is useless

Therefore, claim X is rejected

 

Example. “He suggested that the government ought to reduce its taxes on imports. What does that corrupt drunkard know about economic policy!”

 

#7 Tu Quoque

In Latin, Tu Quoque means ‘you too.’ Someone commits this fallacy when they reason that a claim is false because the person who made the claim does not act consistently with it.

 

Person A claims X

But Person A acts contrary to claim X

Therefore, claim X should be rejected

 

Example; “You are lecturing me about driver’s safety when you’re the one who practically never wears a seatbelt! Why should I listen to you?”

 

#8 Moving the Goalposts

This is when the arguer, changes the parameter of their claim in the middle of a discussion, in order to avoid evidence that might falsify it.

 

Person A claims X

Person B refutes claim X with evidence

Person A claims X1

Person B refutes claim X1 with evidence

Person A claims X2

 …                                                  

Example: Paul claims to have Extra Sensory Perception (ESP).

“I can read minds,” he says. 

His abilities are put to the test. 

Paul fails… 

He reasons: “but it’s just that the individual has to be functioning predominantly at an Alpha state.” [He moves the goalpost]

Paul’s abilities are put to the test again. He fails the second time as well… 

 “Well, I am only able to read minds that are operating on Alpha, but also, the individual must be a believer of ESP!” [He moves the goalpost again]

Each time Paul fails, he re-defines the parameters of his claim to the point where it would be impossible to test the validity of his mysterious powers.    

 

#9 Straw Man

Another commonly abused logical fallacy. To straw man is when an individual distorts, exaggerates or misrepresents their opponent’s claim.  

 

Person A makes claim X

         Person B distorts claim X

Person B challenges Person A with distorted claim X

 

Example:

John: “It’s has been observed that cats prefer to sleep in warm places.”

Jane: “So you’re saying that cats are responsible for global warming!?”

Example:

Person A: “The government should cut down its military expenditures and focus on other sectors.”

Person B: “Would you believe it, the senator wants to leave our nation defenseless!”

 

#10 False Dilemma

When someone presents a situation where only two alternatives are considered, when in fact there are other options.  

 

Either X or Y

 

Example: “If you’re not married, then you must be a bachelor.”

Example: “You are either with us or against us.”

 

#11 Circular Reasoning

Circular reasoning is when someone makes a claim and instead of providing reasons to support it, they merely restate that claim in different terms.  

 

X because X1,

         X1 because X.

 

Example: “Rock music is better than country music because country music is not as good as rock music.”

Example: “This box of Kellogg’s cornflakes is the healthiest cereal out there because it says so right here on its packaging, ‘healthy choice.’ ”

 

#12 Cum Hoc Ergo Propter Hoc

Cum Hoc Ergo Propter Hoc in Latin, translates to “with this, therefore because of this.” One commits this fallacy when they incorrectly reason that because two events occurred at the same time, one must have caused the other.

 

Events X and Y occurred at the same time

         Therefore, X caused Y

                          

Example. “The four years when the President was at the office, our economy had the lowest unemployment rates.”

 

#13 Appeal to False Authority

When someone reasons that a claim is true because a person in a position of authority said it is. Appeal to false authority is a fallacy because someone being an expert or authority in one particular field does not make them an expert in another. 

 

Person A is an authority

         [Person A is not an expert on the topic]

                  Person A says X      

                           Therefore X must be true

 

Example. “We shouldn’t let 17-year-olds vote! My sister is a teacher and she told me that her teenage students are way too young and immature to make such a decision.”

 

#14 Appeal to Pity

The Appeal to Pity fallacy occurs when someone attempts to win an argument by evoking feelings of pity instead of using reason. 

 

If X was true, it would be terrible

         Therefore, X must not be true

 

Example: “Your Honor, if my client goes to prison, then he will be unable to care for his elderly parents. Please consider his circumstances before reaching a verdict.”

 

#15 Appeal to Force

When an arguer uses the threat of physical or psychological harm to coerce another party to accept (or drop) a particular conclusion.

 

Accept X or you will be hurt

 

Example: “If you want to be a part of this team, I suggest that you put in some effort and start contributing more.”

Example: “Make sure you’re back by five! Need I remind you about what happened the last time you stayed out late?”

 

#16 Slippery Slope

Slippery slope fallacy is when someone rejects a course of action whilst reasoning that this small action step will trigger a chain of successive events, that will eventually lead to a bad outcome.

 

If A, then B

If B, then C

If C, then D

Therefore, we shouldn’t do A.

Example. “If the drinking age was lowered then the next thing you know is that these kids will be allowed to drive when they’re 13 and vote when they’re 15! It’s a bad idea, we shouldn’t lower the legal drinking age.”

 

Those were the 16 most common logical fallacies that you’ll encounter in most arguments. Whilst this is not a comprehensive list of logical fallacies, it’s a starting point to help you identify when you’re on the receiving end of poor attempts to convince, deceptive manipulation and half-truths.