Reasoning Roots Worksheet Reasoning Roots Worksheet
Investigating Aristotle and Descartes
Name:
Date:
Part 1: The Thinkers
As you watch the video, record the core ideas of these two philosophers regarding how we find the truth.
Aristotle (4th Century BCE)
Inductive Reasoning
Definition/Method:
Visualizing the Logic:
Specific Observations General Conclusion
René Descartes (17th Century)
Deductive Reasoning / Skepticism
View on Human Senses:
The Only Tool for Truth:
Part 2: Categorizing Logic
Read the following statements. Categorize them as Inductive or Deductive and explain your reasoning based on the video's definitions.
"All swans I have seen are white, therefore all swans are white."
Inductive
Deductive
Why?
"All birds have feathers. A robin is a bird. Therefore, a robin has feathers."
Inductive
Deductive
Why?
"The sun has risen every morning so far. Therefore, it will rise tomorrow."
Inductive
Deductive
Why?
Part 3: Descartes' Challenge
Descartes famously said, "Cogito, ergo sum" (I think, therefore I exist). He believed we should doubt everything our eyes and ears tell us.
Why did Descartes trust mathematics more than his own human senses?
In your daily life, when is it better to use inductive reasoning (observing patterns), and when is it safer to use deductive reasoning (logic and math)?
Logic Lab Slides Logic Lab
Reasoning, Science, and the Pursuit of Truth
8th Grade Critical Thinking ELA
The Seeds of Science
Hook: Aristotle & The Time Machine
Inductive Reasoning
Making specific observations to reach a general conclusion.
"Aristotle planted the early seeds of the scientific method."
Let's Watch:
"You're right in the middle of a great kitten video when a horror strikes..."
Video Start: 0:00 - 5:00
The Thinkers
Watch & Take Notes (Worksheet Part 1)
Embedded media
Aristotle (4:55)
• Specific → General
• Observations first
Descartes (9:14)
• Skepticism of senses
• Trust in Mathematics
Discussion Tip:
Why does Descartes think our senses can lie?
The Logic Challenge
Applying Aristotle and Descartes
Task:
1 Identify if the statement is Inductive or Deductive .
2 Use the video's vocabulary (Specific, General, Skepticism, Observations).
"All humans are mortal. Socrates is human. Therefore, Socrates is mortal."
Aristotle? OR Descartes?
Closing Thought
If you couldn't prove something mathematically, well, then there was reason to doubt it.
Why did René Descartes trust numbers more than his own eyes?
Logic Lab Teacher Guide Logic Lab Teacher Guide
8th Grade ELA / Critical Thinking | Lesson Plan & Keys
Lesson Overview
Objective
Students will distinguish between inductive and deductive reasoning using text evidence from the historical thinkers Aristotle and René Descartes.
Materials
Logic Lab Slides
Reasoning Roots Worksheet
Thinker's Transcript Reference
Video: "The Scientific Method - Origins..."
Pacing (50 min)
Hook (Aristotle/Inductive) 05m
Video & Note-taking 15m
Application Activity 20m
Closure Discussion 10m
Worksheet Answer Key
Part 1: The Thinkers
Aristotle: Inductive reasoning is the use of specific observations to reach a general conclusion. He "planted the seeds" of experimentation.
Descartes: Believed human senses were untrustworthy and could misinterpret information. Reached the conclusion that math is the only way to prove truth beyond doubt.
Part 2: Application
Statement Category Reasoning (Look for these keywords) White Swans Inductive Specific observation (seen swans) → general conclusion (all swans). Robins/Feathers Deductive General truth (all birds) applied to a specific case (a robin). Sunrise Tomorrow Inductive Patterns from the past (specific instances) applied to the future.
Part 3: Descartes' Challenge
Math over Senses: Math is logical and universal. Senses can be fooled (optical illusions, mistakes), but 2+2 is always 4. If you can't prove it mathematically, you can doubt it.
Application: Inductive is great for everyday survival (predicting behavior, weather). Deductive is safer for high-stakes science, engineering, and structural logic where 100% certainty is needed.
Discussion Facilitation
Misconception Alert
Students often think "Inductive" means "Inaccurate." Remind them that science relies on *both*. Aristotle’s specific observations are what provide the data for the general rules.
Questioning Framework
Check for Understanding: How would Aristotle and Descartes differ on a witness's testimony in a court case? Thinker's Transcript Reference Thinker's Transcript Reference
Video: The Scientific Method - Origins, Thinkers, and Social Impact
Lesson Resource
Use this transcript to cite specific evidence in your worksheet. Pay close attention to the sections marked for Aristotle and Descartes .
[04:50]
Introduction to Ancient Philosophy
To tell the full story of the scientific method, we have to hop in the time machine and go back to Ancient Greece and the 4th Century BCE.
[04:55]
Aristotle: Inductive Reasoning
There, the philosopher Aristotle advocated the use of inductive reasoning , or making specific observations to reach a general conclusion . Aristotle, you could say, planted the early seeds of the scientific method.
[05:19]
Next, let's fast forward to the year 1000 CE... Ibn al-Haytham studied the movement of light using lenses and mirrors. He meticulously observed his findings, created hypotheses, and tested his hypotheses systematically.
[07:08]
Bacon believed that people should reject scholasticism... Instead, he advocated empiricism, using the five human senses to gain firsthand knowledge of natural processes through observation and experimentation.
[09:14]
René Descartes: Deductive Skepticism
René Descartes was born three decades after Galileo and Bacon. He was a French philosopher and mathematician who agreed with Bacon. Modern scientists should reject antiquated assumptions about the world. Descartes, however, essentially believed human senses couldn't be trusted at all . Even reaching logical conclusions based on observation wasn't enough. Flawed reasoning could lead to false logic.
[09:43]
Descartes felt that questions could be answered. But there was only one way: math . He was pretty sure that he himself existed, saying 'Cogito, ergo sum'—I think, therefore I exist. Other than that, if you couldn't prove something mathematically, well, then there was reason to doubt it.
[10:06]
Summary: Bacon said, 'Hey, here's how you observe, experiment, and reach a logical conclusion.' Galileo put it into practice and called for others to corroborate his findings through independent confirmation. And Descartes was like, 'How do you know what you think you know? Can you keep seeking further answers?'
Space for Evidence Analysis 
