Logic & Reasoning

Critical Thinking Unit - Lesson 4 of 22 | Year 9-10 | Social Studies

🌿 Whakataukī (Māori Proverb)

"He aha te mea nui o te ao? He tangata, he tangata, he tangata"

Meaning: What is the most important thing in the world? It is people, it is people, it is people

Today we learn that good reasoning serves people - it helps us make better decisions and understand truth together. In te ao Māori, wisdom comes through collective reasoning and listening to all voices.

🎯 Learning Objectives

By the end of this lesson, you will be able to:

🔍 Engage: Reasoning in Daily Life

We use reasoning constantly! Click each scenario to see different types of reasoning at work:

🧠 Explore: Types of Logical Reasoning

🔬 Deductive Reasoning

Pattern: General rule → Specific case → Certain conclusion

NZ Example:

• All NZ citizens can vote at 18
• Aroha is a NZ citizen who is 19
• Therefore, Aroha can vote

🔍 Inductive Reasoning

Pattern: Specific observations → General pattern → Probable conclusion

NZ Example:

• Wellington has been windy every day this week
• It was windy last week too
• Therefore, Wellington is probably a windy city

💡 Abductive Reasoning

Pattern: Observation → Best explanation → Likely conclusion

NZ Example:

• The kauri trees are dying
• There's a known disease called kauri dieback
• The trees probably have kauri dieback disease

🤝 Activity: Reasoning Detective

In groups of 3, examine the following NZ-based scenarios and identify the type of reasoning used. Be prepared to explain your choices:

  1. "Every All Blacks game I've watched this year, they've won. They'll probably win today too."
  2. "All public transport in Auckland requires a HOP card. I need to catch the bus, so I need a HOP card."
  3. "My phone battery died suddenly, and I noticed it's been getting hot lately. It probably needs replacing."

Time: 10 minutes

🌺 Te Ao Māori: Collective Reasoning

In Māori tradition, decision-making often follows collective reasoning processes:

This approach values the collective wisdom and ensures decisions benefit the whole whānau/community.

🚫 Common Logical Fallacies

Understanding fallacies helps us spot weak reasoning. Here are some common ones in New Zealand contexts:

🎯 Ad Hominem (Attacking the Person)

Example: "Don't listen to her views on housing policy - she's too young to understand."

Why it's wrong: Age doesn't automatically invalidate someone's reasoning about policy.

🌊 Bandwagon Fallacy

Example: "Everyone's moving to Australia, so it must be better than NZ."

Why it's wrong: Popular choices aren't automatically correct choices.

⚡ False Cause

Example: "Since the new government came in, house prices rose. The government caused high house prices."

Why it's wrong: Correlation doesn't equal causation - many factors affect house prices.

🎭 Straw Man

Example: "You support the smoking ban? So you want to control every aspect of people's lives!"

Why it's wrong: This misrepresents the original position to make it easier to attack.

🕵️ Fallacy Hunt

Find examples of these fallacies in:

  • Social media posts about New Zealand issues
  • Letters to the editor in NZ newspapers
  • Political debates or speeches

Document one example and explain why it's a fallacy. Share with a partner.

Time: 15 minutes

🏗️ Building Strong Arguments

A well-constructed argument has three key parts:

  1. Premises: The evidence or reasons you're starting with
  2. Logic: How your premises connect to your conclusion
  3. Conclusion: What you're arguing for

🎯 Practice: Argument Construction

Topic: Should New Zealand lower the voting age to 16?

Let's build arguments together. Consider:

  • What premises (evidence/facts) might support each side?
  • How do these premises logically connect to the conclusion?
  • What might be the strongest argument for each position?

🛡️ SIFT Method for Logical Claims

When you encounter arguments and claims, use SIFT to evaluate their logical strength:

🛑 STOP

Pause and ask: What is the actual claim being made? What's the evidence? Do I notice any immediate logical problems?

🔍 INVESTIGATE the Logic

Check: Are the premises actually true? Does the conclusion follow from the premises? Are there any logical fallacies?

📊 FIND Better Reasoning

Look for: More complete arguments, counter-evidence, expert analysis of the logical structure.

🔗 TRACE the Argument Chain

Follow: What are the underlying assumptions? What evidence supports each premise? Where did this reasoning originate?

🚀 SIFT Practice: Political Logic

Scenario: "Young people don't vote because they don't care about politics. Therefore, we shouldn't lower the voting age."

Apply SIFT to analyze this argument:

  1. Stop: What's the claim? What's the reasoning?
  2. Investigate: Is the premise true? Does the conclusion follow?
  3. Find: What other explanations or evidence exist?
  4. Trace: What assumptions underlie this argument?

📝 Assessment: Argument Analysis & Construction

Part A: Fallacy Identification (10 minutes)

Read the provided arguments about New Zealand issues. Identify any logical fallacies and explain why they weaken the reasoning.

Part B: Argument Construction (20 minutes)

Choose one of these New Zealand topics and construct a well-reasoned argument:

Your argument must include:

Success Criteria: Demonstrates understanding of logical reasoning principles, constructs coherent arguments, shows cultural awareness in reasoning.

🤔 Reflect & Connect

Individual Reflection (5 minutes):

  • How has learning about logical fallacies changed how you evaluate arguments?
  • Which type of reasoning (deductive, inductive, abductive) do you use most in daily life?
  • How might Māori approaches to collective reasoning improve decision-making in your community?

Pair Share:

Share one fallacy you've noticed in recent news or social media. Discuss how the argument could be strengthened.

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