Worked Examples
Fallacies and puzzle-solving strategies.
1Worked Example
Problem
Identify the fallacy: "Professor Jones says climate change is a hoax. He's a professor, so he must be right."
1
This appeals to authority — but what is the professor's field?
2
If Prof. Jones teaches literature, his opinion on climate science carries no special weight.
3
Fallacy: Appeal to Authority — Expertise doesn't transfer across fields.
⚠
Watch Out!
Not all authority appeals are fallacious — citing a climate scientist ON climate is fine!
2Worked Example
Problem
Knights & Knaves: A says "B is a knave." B says "We are different types." What are A and B?
1
Assume A is a Knight (truth-teller):
2
Then "B is a knave" is TRUE → B is a knave.
3
B (knave) says "We are different types" — this must be FALSE.
4
But A=Knight, B=Knave ARE different types! Contradiction. ✗
5
Assume A is a Knave (liar):
6
Then "B is a knave" is FALSE → B is a knight.
7
B (knight) says "We are different types" — this must be TRUE.
8
A=Knave, B=Knight ARE different types! ✓ Consistent.
9
Answer: A is a Knave, B is a Knight.
3Worked Example
Problem
Identify the fallacy: "We shouldn't raise the minimum wage. Next thing you know, they'll want $100/hour, and all businesses will close."
1
This claims a modest action will lead to extreme consequences.
2
No causal chain is provided for why this progression is inevitable.
3
Fallacy: Slippery Slope — Assumes cascade without evidence.
✦Tip
For Knights & Knaves: Assume one case, trace ALL implications, check for contradictions. No contradiction = valid solution.