11-17-2025, 08:33 AM
Logical Fallacies — The Hidden Traps That Break Reasoning
Even the smartest thinkers fall into logical traps. These errors in reasoning — called fallacies — can make arguments look convincing while being completely wrong. Understanding them is essential for mathematics, science, philosophy, and everyday critical thinking.
This thread explores the most important fallacies, how to spot them, and why they weaken an argument instantly.
1. What Is a Logical Fallacy?
A logical fallacy is an error in reasoning that weakens an argument.
Fallacies can appear in:
• debates
• scientific arguments
• news
• social media
• everyday conversations
They often sound persuasive, which is why they’re so effective.
2. The Two Types of Fallacies
A. Formal Fallacies (errors in structure)
These break the rules of logic itself.
Example:
“If A implies B, and B is true, then A must be true.”
This is the fallacy of affirming the consequent.
B. Informal Fallacies (errors in content)
These come from flawed assumptions, emotional tricks, or irrelevant points.
Example:
“You can’t trust her argument because she’s young.”
This is an ad hominem fallacy.
3. Common Logical Fallacies Everyone Should Know
Ad Hominem — attacking the person, not the argument.
Strawman — misrepresenting someone’s argument to defeat it easily.
Appeal to Authority — assuming something is true because an expert said it.
False Dichotomy — acting like only two options exist.
Circular Reasoning — the argument uses its own conclusion as proof.
Slippery Slope — claiming one step will lead to extreme outcomes.
Appeal to Emotion — using fear, guilt, or sympathy instead of logic.
Post Hoc Fallacy — assuming A caused B just because A happened first.
Hasty Generalisation — drawing big conclusions from tiny evidence.
4. Why Fallacies Matter in Mathematics
Mathematics depends on clean, airtight logic.
If reasoning breaks, the entire proof collapses.
Avoiding fallacies leads to:
• stronger arguments
• cleaner reasoning
• deeper understanding
• better problem-solving
5. How to Avoid Logical Fallacies
• Question assumptions
• Ask whether the conclusion *actually follows*
• Check for missing steps
• Focus on evidence
• Avoid emotional reasoning
• Be open to revising your view
Summary
Logical fallacies:
• weaken arguments
• mislead people
• appear everywhere
• must be understood for good reasoning
Written by LeeJohnston & Liora — The Lumin Archive Research Division
Even the smartest thinkers fall into logical traps. These errors in reasoning — called fallacies — can make arguments look convincing while being completely wrong. Understanding them is essential for mathematics, science, philosophy, and everyday critical thinking.
This thread explores the most important fallacies, how to spot them, and why they weaken an argument instantly.
1. What Is a Logical Fallacy?
A logical fallacy is an error in reasoning that weakens an argument.
Fallacies can appear in:
• debates
• scientific arguments
• news
• social media
• everyday conversations
They often sound persuasive, which is why they’re so effective.
2. The Two Types of Fallacies
A. Formal Fallacies (errors in structure)
These break the rules of logic itself.
Example:
“If A implies B, and B is true, then A must be true.”
This is the fallacy of affirming the consequent.
B. Informal Fallacies (errors in content)
These come from flawed assumptions, emotional tricks, or irrelevant points.
Example:
“You can’t trust her argument because she’s young.”
This is an ad hominem fallacy.
3. Common Logical Fallacies Everyone Should Know
Ad Hominem — attacking the person, not the argument.
Strawman — misrepresenting someone’s argument to defeat it easily.
Appeal to Authority — assuming something is true because an expert said it.
False Dichotomy — acting like only two options exist.
Circular Reasoning — the argument uses its own conclusion as proof.
Slippery Slope — claiming one step will lead to extreme outcomes.
Appeal to Emotion — using fear, guilt, or sympathy instead of logic.
Post Hoc Fallacy — assuming A caused B just because A happened first.
Hasty Generalisation — drawing big conclusions from tiny evidence.
4. Why Fallacies Matter in Mathematics
Mathematics depends on clean, airtight logic.
If reasoning breaks, the entire proof collapses.
Avoiding fallacies leads to:
• stronger arguments
• cleaner reasoning
• deeper understanding
• better problem-solving
5. How to Avoid Logical Fallacies
• Question assumptions
• Ask whether the conclusion *actually follows*
• Check for missing steps
• Focus on evidence
• Avoid emotional reasoning
• Be open to revising your view
Summary
Logical fallacies:
• weaken arguments
• mislead people
• appear everywhere
• must be understood for good reasoning
Written by LeeJohnston & Liora — The Lumin Archive Research Division