Common Logical Fallacy People Often Do
“Mathematics is not about numbers, equations, computations, or algorithms: it is about understanding” — William Paul Thurston (Mathematician)
In this story, I would like to share a common misconception or fallacy of logic that people often do. No… it’s not gonna be a theoretical or an analytical story. I just want to share my perspective on this particular topic. It’s gonna contain a little bit of material on Discrete Mathematics. But don’t worry, it’s not gonna be math-heavy-type of a story 😀 I’m no expert in Mathematics. Believe me guys, I got a B- in my college year for this class 😂 So I’m going to say this firsthand: sorry if I’m not using scientific terms in this story and also if I mistyped or misused a term. I will try to explain this story in the simplest way possible. So without further ado, let’s get started!
1. Misconception
The issue that triggers me to write this story is the common misconception people often get related to sickness and symptoms. Have you ever heard that if you have sweaty hands, then you got heart disease?
This is a logical fallacy. The correct one is if you have heart disease, you probably got sweaty hands.
In Discrete Mathematics, we learned about one logical operator called implication (→) Ex: p → q. It means “p implies q”. This logical relation explains “cause and effect”, or in other words “causality”.
A common example of this is: “it’s raining” → “bring an umbrella”
If we translate it to human language, it will sound: “If it’s raining, then bring an umbrella”
Or my preferred way to read that is: “cause it’s raining, as the result bring an umbrella”
So with that said, can we say if someone brings an umbrella that means it’s raining outside? No way, that’s ridiculous, right? Same as my example about the relation between sweaty hands and heart disease above. It will be ridiculous to say that a person with sweaty hands is having heart disease. Because the correct way to explain sickness and symptoms is sickness → symptoms not the other way around (symptoms → sickness).
Like the arrow symbol is trying to tell us ( →), this relation is merely one-way. It means we can’t reverse the statement cause it will result in a logical fallacy. So next time you see a person being nervous and got sweaty hands — don’t worry, they are not having heart disease.
2. Bi-implication
But there is one reversible relationship which is a bi-implication (↔). As the symbol implies, it indicates that both of the statement is affecting each other. For example:
He's a man <--> He's got a male reproductive organ
We can sound it both ways:
- cause he’s a man, as the result he’s got a male reproductive organ
- cause he’s got a male reproductive organ, as the result he’s a man
and both of the statements above are true.
3. Tips
I would like to share a simple tip you can use so you won’t face the same logical fallacy in the future. Please note this is just my tip 😂 which is not scientifically accurate.
The first thing to do is to determine which fact is the cause of the other fact that is happening. To put it as an example, you need to determine which facts are the “sickness” and “symptoms”. By doing this, you’ll see the relationship between the two facts and can deduct information correctly. If the fact lands on the right side of the arrow (symptoms), then the other fact on the left side may or may not be true (it can be false). If a person brings an umbrella, it might not be raining outside.
Secondly, see if the two facts can be considered as a cause. If it is, then it’s a bi-implication relationship and you don’t need to worry about the logical fallacy cause it’s pretty trivial since you can sound it both ways and the relationship between the two facts will always be true 😁
