🎯 Critical Reasoning: Become a Detective of Arguments
Imagine you’re a detective. But instead of solving crimes, you’re solving puzzles made of words and ideas. Welcome to Critical Reasoning!
🌟 What Is Critical Reasoning?
Think of an argument like a building made of blocks:
- The conclusion is the roof (what someone wants you to believe)
- The premises are the walls and foundation (the reasons they give)
- Assumptions are invisible glue holding it all together
Your job as a detective? Find out if the building is strong or if it might fall down!
graph TD A["🧱 Premises<br>The Evidence"] --> B["🏗️ Assumptions<br>Hidden Connections"] B --> C["🏠 Conclusion<br>What They Want You to Believe"]
🔍 The Six Detective Skills
Let’s learn the six superpowers every reasoning detective needs!
1️⃣ Strengthening Arguments 💪
What is it? Making an argument STRONGER by adding helpful information.
🎪 The Circus Analogy
Imagine a circus tent held up by ropes. If some ropes are weak, the tent might fall. Strengthening is like adding MORE strong ropes!
Simple Example
Argument:
“The school should get a new playground because kids will be happier.”
What would STRENGTHEN this?
“Studies show that kids who play more have better moods and grades.”
This is like adding a strong rope! Now we have PROOF that playgrounds help.
🎯 How to Find Strengtheners
Ask yourself:
- Does this give more evidence for the conclusion?
- Does it make the hidden assumption more likely true?
- Does it remove a doubt someone might have?
Quick Practice
Argument: “Eating vegetables makes you healthy.”
Which strengthens it?
- ✅ “Doctors found that people who eat vegetables live longer.”
- ❌ “Vegetables come in many colors.”
The first one gives PROOF. The second one is just a random fact!
2️⃣ Weakening Arguments 🔨
What is it? Making an argument WEAKER by showing problems with it.
🎪 Back to Our Circus Tent
If strengthening is adding ropes, weakening is like showing that some ropes are frayed or the ground is slippery!
Simple Example
Argument:
“Everyone should drink coffee because it helps you wake up.”
What would WEAKEN this?
“Too much coffee can make your heart beat too fast and make you sick.”
Now we see a PROBLEM with the idea!
🎯 How to Find Weakeners
Ask yourself:
- Does this show the conclusion might be wrong?
- Does this attack the hidden assumption?
- Does this show the evidence is not reliable?
Quick Practice
Argument: “Dogs are the best pets because they’re friendly.”
Which weakens it?
- ✅ “Cats can also be very friendly and need less care.”
- ❌ “Dogs come in many sizes.”
The first shows dogs might NOT be the “best” — other pets have good qualities too!
3️⃣ Identifying Assumptions 🔎
What is it? Finding the HIDDEN beliefs that the argument depends on.
🌉 The Invisible Bridge
Imagine someone says: “I live on one side of a river. My school is on the other side. So I can get to school.”
Wait! They assumed there’s a bridge or a boat! That’s the hidden assumption.
graph LR A["🏠 My Home"] --> B["❓ Hidden Assumption<br>There is a bridge!"] B --> C["🏫 School"]
Simple Example
Argument:
“It’s raining outside, so you should take an umbrella.”
Hidden Assumption:
“You don’t want to get wet.”
If you LOVE getting wet, you don’t need an umbrella!
🎯 How to Find Assumptions
Ask yourself:
- What MUST be true for this argument to work?
- What is the speaker NOT saying but BELIEVING?
- If this hidden thing was FALSE, would the argument fall apart?
The Gap Test
Look for the gap between the evidence and the conclusion. The assumption fills that gap!
| Evidence | Conclusion | Hidden Assumption |
|---|---|---|
| “It’s sunny” | “We’ll have a picnic” | The picnic depends on weather |
| “He studied hard” | “He’ll pass the test” | Studying leads to passing |
| “She’s tall” | “She’s good at basketball” | Height helps in basketball |
4️⃣ Drawing Inferences 🧩
What is it? Figuring out what MUST be true based on what you’re told.
🎁 The Present Box
If someone tells you: “The box is red, and there’s a toy inside,” you can INFER (figure out) that “There’s a toy in a red box.”
You’re putting pieces together like a puzzle!
Simple Example
Given Information:
“All cats have whiskers. Fluffy is a cat.”
What can you INFER?
“Fluffy has whiskers.”
This MUST be true!
🎯 Rules for Good Inferences
graph TD A["✅ MUST be true<br>No other option"] --> D["Good Inference!"] B["❌ MIGHT be true<br>Just possible"] --> E["Bad Inference!"] C[❌ COULD be true<br>We don't know] --> E
Watch Out!
Don’t confuse “must be true” with “might be true”!
| Statement | Inference | Good or Bad? |
|---|---|---|
| “All birds have wings” + “Sparrows are birds” | “Sparrows have wings” | ✅ Good! |
| “Some dogs are big” | “All dogs are big” | ❌ Bad! Only SOME! |
| “It usually rains in April” | “It will definitely rain in April” | ❌ Bad! Only usually! |
5️⃣ Finding Flaws 🕳️
What is it? Spotting MISTAKES in how someone is reasoning.
🍕 The Pizza Logic Problem
Bad Argument:
“Pizza has cheese. I love cheese. Therefore, pizza is the healthiest food.”
Wait! Loving cheese doesn’t make pizza HEALTHY! That’s a flaw!
Common Flaws (Mistakes)
1. Confusing Correlation with Cause
“Every time I wear my lucky socks, my team wins.”
Socks don’t CAUSE winning! It’s just coincidence!
2. Attacking the Person, Not the Idea
“You can’t trust what she says about exercise because she’s not an athlete.”
Her idea could still be correct!
3. Assuming Everyone Agrees
“Everyone knows chocolate is the best flavor.”
Not everyone agrees! That’s an assumption, not a fact!
4. False Either/Or
“Either you’re with us, or you’re against us.”
Maybe someone is neutral! There are more than two options!
5. Hasty Generalization
“I met two rude people from that city. Everyone there must be rude.”
Two people don’t represent EVERYONE!
🎯 Quick Flaw Finder
| The Argument Says | The Flaw Is |
|---|---|
| “A happened, then B happened, so A caused B” | Confusing sequence with cause |
| “Most people believe X, so X is true” | Appeal to popularity |
| “This expert says so” (on unrelated topic) | Misusing authority |
| “If we allow X, terrible Y will follow!” | Slippery slope |
6️⃣ Parallel Reasoning 🪞
What is it? Finding arguments that have the SAME STRUCTURE even if they talk about different things.
🎭 The Copy Machine
Imagine you have a recipe for cookies. You could use the SAME recipe but with different ingredients to make brownies. The STRUCTURE is the same!
Simple Example
Original Argument:
“All dogs are animals. Buddy is a dog. So Buddy is an animal.”
Parallel Argument (same structure):
“All roses are flowers. This plant is a rose. So this plant is a flower.”
Both use this pattern:
- All X are Y
- This thing is X
- So this thing is Y
🎯 How to Match Structures
Ignore the specific words. Look at the PATTERN!
graph TD A["Original: All cats are mammals"] --> B["Pattern: All A are B"] C["Parallel: All squares are shapes"] --> B D["NOT Parallel: Some birds can fly"] --> E["Different Pattern!"]
Practice Matching
Original: “If it rains, the ground gets wet. It rained. So the ground is wet.”
Pattern: If P then Q. P happened. So Q happened.
Which is parallel?
- ✅ “If you study, you’ll pass. You studied. So you’ll pass.”
- ❌ “If you study, you’ll pass. You passed. So you studied.” (This is backwards!)
🎮 Putting It All Together
Here’s a complete example using all six skills:
The Argument:
“Video games make kids violent. Tommy plays video games a lot, and yesterday he was mean to his sister. We should ban all video games.”
Using Our Six Skills:
| Skill | What We Find |
|---|---|
| Find the Assumption | Video games CAUSE the meanness (not something else) |
| Strengthen It | A study shows kids who play violent games are more aggressive |
| Weaken It | Tommy was mean because his sister broke his toy |
| Find the Flaw | One example (Tommy) doesn’t prove all video games cause violence |
| Draw an Inference | If the argument is right, all gamers should be violent (but they’re not!) |
| Parallel Reasoning | “Books have violence. Kids read books. Ban all books.” (Same bad logic!) |
🌈 Remember This!
graph TD A["🔍 Critical Reasoning"] --> B["💪 Strengthen<br>Add support"] A --> C["🔨 Weaken<br>Find problems"] A --> D["🔎 Assumptions<br>Find hidden beliefs"] A --> E[🧩 Inferences<br>Figure out what's true] A --> F["🕳️ Flaws<br>Spot mistakes"] A --> G["🪞 Parallel<br>Match patterns"]
You’re now a Reasoning Detective! 🕵️
Every argument you hear is like a puzzle. Sometimes the pieces fit perfectly. Sometimes they’re missing pieces. Sometimes the pieces are in the wrong places.
Your job? Find the truth!
🎯 Quick Reference Card
| When They Ask… | You Should… |
|---|---|
| “What strengthens this?” | Look for SUPPORTING evidence |
| “What weakens this?” | Look for PROBLEMS or counter-examples |
| “What’s the assumption?” | Find the HIDDEN belief |
| “What can you infer?” | Find what MUST be true |
| “What’s the flaw?” | Name the REASONING mistake |
| “Which is parallel?” | Match the STRUCTURE, not the topic |
Now go forth and detect! Every conversation, every advertisement, every argument is a puzzle waiting to be solved. You have the tools. Use them wisely! 🎓✨