How to Spot a Mental Trap — The Logic of Fallacies

✍️ Inspired by Logically Fallacious by Bo Bennett, PhD

(Direct quotations reproduced from the Academic Edition, 2020)

🧠 What Is a Logical Fallacy, Exactly?

If you’ve ever listened to an argument that sounded right but felt wrong, congratulations — you’ve probably met your first logical fallacy.

Bo Bennett opens his third section with a deceptively simple question:

“What is a logical fallacy, exactly?”

And his answer cuts right to the point:

“An error in reasoning.”

That’s it. A fallacy isn’t just a mistake or a lie — it’s a flaw in the logic of how we connect ideas. It’s not about what you believe, but how you came to believe it.

Bo traces the term all the way back to its Latin root, fallacia, meaning “deception” or “trick.” In his words:

“The word ‘fallacy’ comes from the Latin fallacia, which means ‘deception, deceit, trick, artifice,’ however, a more specific meaning in logic (a logical fallacy) that dates back to the 1550s means ‘false syllogism, invalid argumentation.’”

A fallacy, then, is like a mental magic trick — it makes a bad argument look good.

🎭 The Difference Between Being Wrong and Being Fallacious

One of Bo Bennett’s most important clarifications is this:

“Factual errors are not fallacies.”

If someone says, “The sun is 30 miles from the earth,” that’s not a fallacy — it’s just wrong.

A fallacy happens when the reasoning process itself goes off the rails — when the structure of the argument is deceptive, even if the facts are true.

For example:

“Timmy is a poo-poo face; therefore, Timmy is wrong.”
This is not a factual error. It’s an error in reasoning.

You’ve attacked Timmy’s face, not his logic.

🧮 Two Types of Fallacies — Formal and Informal

Bo explains that fallacies come in two main categories:

Formal Fallacies – Errors in the structure of an argument (like a broken formula).
Informal Fallacies – Errors in the content of an argument (like using bad evidence or emotion instead of logic).

“Formal fallacies are classified by their structure (logical form), while informal fallacies are classified by their content.”

A formal fallacy is like saying:

“No X are Y. Some Z are X. Therefore, some Z are Y.”

Looks neat — but it’s structurally invalid.

An informal fallacy is like saying:

“Timmy is wrong because he’s ugly.”

It’s not broken math — it’s broken reasoning.

Bo warns us not to expect to see formal syllogisms in everyday life:

“We rarely see one present a formal syllogism that is subject to a formal fallacy. What we find in real life is a bunch of words that need to be parsed into an argument.”

So don’t go hunting logic puzzles in coffee shop debates — real-world fallacies are messier, sneakier, and much more common.

🧩 Fallacies vs. Cognitive Biases — A Friendly Distinction

You’ve heard of cognitive bias, right? That’s your brain’s tendency to take shortcuts — like assuming something is true just because it’s popular or recent.

Bo Bennett clarifies the link beautifully:

“The main difference… is that logical fallacies require an argument, whereas cognitive biases and heuristics refer to a problematic pattern of thinking.”

Example:

Cognitive Bias: “Everyone is buying this stock, so it must be good.”
Logical Fallacy: “Everyone is buying this stock; therefore, it must be the right investment.”

One is a mental habit, the other is an argument built on that habit.

🚧 Why Fallacies Matter — The Hidden Danger

Fallacies are deceptive because they often sound reasonable.
As Bo puts it:

“Logical fallacies are not always easy to spot, especially to the untrained mind. Yet they often elude our critical faculties, making them persuasive for all the wrong reasons — sort of like optical illusions for the mind.”

They trick us into confidence.
They make bad reasoning feel like common sense.
And they spread fast — especially online.

Spotting them doesn’t just make you smarter — it makes you harder to manipulate.

🎯 Dr. Bo’s Three Criteria for a Logical Fallacy

Bo Bennett gives us a crystal-clear checklist for what really counts as a logical fallacy:

“1. It must be an error in reasoning, not a factual error.
2. It must be commonly applied to an argument either in the form of the argument or the interpretation of the argument.
3. It must be deceptive in that it often fools the average adult.”

If it meets these three, congratulations — you’ve found a true fallacy.

🗣️ Let’s Meet a Few Early Examples

To make it real, let’s explore two simple but powerful examples Bo starts with in his book.

1. Accent Fallacy (Accentus)

“When the meaning of a word, sentence, or entire idea is interpreted differently by changing where the accent falls.”

Example (from My Cousin Vinny):

Police: “At what point did you shoot the clerk?”
Bill (shocked): “I shot the clerk? I shot the clerk?”
Later in court, the officer reads it as a confession: “He said, ‘I shot the clerk.’”

Here, a simple shift in emphasis changes the meaning completely.
Bo jokes that this is a failure of critical thought — not crime-solving.

2. Accident Fallacy (A Dicto Simpliciter)

“When an attempt is made to apply a general rule to all situations when clearly there are exceptions to the rule.”

Example (from the book):

“I believe one should never deliberately hurt another person; that’s why I can never be a surgeon.”

The reasoning here destroys the exception — surgery does cause pain, but for healing.
Bo writes:

“Simplistic rules or laws rarely take into consideration legitimate exceptions, and to ignore these exceptions is to bypass reason to preserve the illusion of a perfect law.”

🎓 Why You Should Care

Once you start seeing fallacies, you’ll see them everywhere:

In political speeches
In news debates
In ads that say “9 out of 10 people agree”
Even in your own late-night arguments with friends

Bo Bennett calls this ability “a way that you can do your part to bring more truth back into our post-truth world.”

That’s what makes this more than an academic exercise — it’s intellectual hygiene.

💡 Quick Recap

Concept	Meaning	Example
Logical Fallacy	An error in reasoning (not just a wrong fact)	“Timmy is ugly, therefore he’s wrong.”
Formal Fallacy	Flawed logical structure	“No X are Y. Some Z are X. Therefore, some Z are Y.”
Informal Fallacy	Flawed reasoning or evidence	“She’s rich, so she must be right.”
Cognitive Bias	Faulty thinking pattern, no argument needed	“Everyone’s doing it, so it must be good.”

🚀 Call to Action: Train Your “Fallacy Radar”

Watch or read any political or social debate this week.
Write down one argument that made you emotional.
Ask: “What reasoning pattern is being used?”
Check if it’s a factual disagreement or a reasoning fallacy.

And remember Bo’s humor and humility — spotting fallacies isn’t about showing off; it’s about thinking clearly in a noisy world.

🔖 Reference:

Bo Bennett, PhD (2020). Logically Fallacious: The Ultimate Collection of Over 300 Logical Fallacies (Academic Edition). Archieboy Holdings LLC.