Unit 3 Discussion Assignment
Sherlock Holmes: Induction, Deduction or Both?
Sherlock Holmes was a fictional detective created by the British author Sir Arthur Conan Doyle.
Holmes was renowned for his reasoning talents, in particular his ability to “deduce” the causes
and perpetrators of spectacularly heinous crimes. In preparation for this Discussion Forum
assignment, review the following materials and take notes to yourself on any arguments you
detect in both the Video and in the Short Story (attached as a separate PDF):
• Video: Sherlock Holmes’ Reasoning — Induction or Deduction? (ignore the Greek
subtitles), Duration: (4:25), YouTube URL:
• Short Story: The Adventure of the Speckled Band (attached)
Note: “The Adventure of the Speckled Band is one of the 56 short Sherlock Holmes stories
written by Scottish author Sir Arthur Conan Doyle. It is the eighth of the twelve stories collected
in The Adventures of Sherlock Holmes. The story was first published in Strand Magazine in
February 1892, with illustrations by Sidney Paget. It was published under the different title “The
Spotted Band” in New York World in August 1905. Doyle later revealed that he thought this was
his best Holmes story.”
(Quoted from Wikipedia at http://en.wikipedia.org/wiki/The_Adventure_of_the_Speckled_Band)
Given what you’ve learned in this Unit about induction and deduction, think about the arguments
by Holmes in both the Video and in the Short Story. Try to determine if his arguments are
inductive or deductive. Could you possibly spot both? Post your answer to the following guide
questions on the Discussion Forum, then be sure to follow the instructions in Step 3 to comment
on each other’s posts.
• Can you find and reconstruct a deductive argument? (Remember to follow a deductive
form). How about an inductive argument? What’s the difference between the two?
• Is Holmes’ argumentative style a convincing as a method of reasoning? Why or why
not. Be sure to include examples from both the video and the short story.
• Can you think of other disciplines, other than criminal forensics, where Holmesian logic
could be applied?
• Do you ever reason like Holmes? Give us an everyday example of how you might reason
PHIL110 Critical Thinking – SPS CUNY
Instructions for the ‘Critical Thinker’s Peer Commentary’.
Once you completed and posted your response to Sherlock Holmes’ argumentation on the
Discussion Forum, engage with your classmates as a ‘Critical Thinker’.
We all know, it’s all too easy nowadays to just click the ‘Like’ button on our social media
interactions. ‘Oh, I love it!’, or ‘Gee, that’s so sad’ and other emotional reactions are very human
responses. But as we learn to become more critical and logical thinkers, we must begin to
differentiate between purely emotional and more rational reactions. We need to follow-up our
emotive responses with rational and critical considerations. In this discussion form Peer
Commentary, we will begin practicing just that.
On the Discussion Forum, respond to three of your classmates with the following:
Start with one (1) emotional reaction. Choose from the following, or feel free to use another
Emoji. Once you pasted your Emoji into your Discussion reply, explain what you mean by it
and why you chose it. For example, something like this: I liked your argument because… or
Your argument was funny because….
After your emotional reaction, then add at least one (1) cognitive or critical thinking reaction.
Choose from the following or come up with your own. For your cognitive reaction be sure to
explain why you chose it, what you mean by it and give examples from the post to justify your
reaction. For example, something like this: I found the evidence you provided in your argument
very convincing because… or Your argument made good connections between….x and y. Be
specific and give details.
PHIL110 Critical Thinking – SPS CUNY
Recommendations for Success and Grading Criteria:
• Respond to the assignment with clear and detailed answers, organized thoughts.
• Follow all assignment prompts and answers all prompt questions.
• Incorporate relevant examples and evidence to support claims.
• Write clearly and without errors a well-composed answer and post it on time.
• Respond to other students with interesting comments and follow-up
questions. Acknowledge all students who commented on your post.