Critical Reasoning
Week 5 Guided Learning Activity: Relevance and Fallacies
Directions: Type the letter answer into Canvas. You may also include the whole line. The letter
comes before the line or sentence
Example:
[A] Paris is the biggest city in France. [B] It is a major cultural center with many famous
museums. [C] The most famous of these museums is the Louvre.
In this passage, A = Paris is the biggest city in France. B = It is a major cultural center with many
famous museums. C = The most famous of these museums is the Louvre.
Section 1: Relevance
Fallacies are mistakes in reasoning. Before we can spot mistakes, we need to understand what
counts as relevant. A positively relevant claim gives a reason to believe something. A negatively
relevant claim gives a reason not to believe something. Read pages 122–124 before starting this
section.
Passage:
The issue is whether Jamal should buy an electric bike
[A] Jamal enjoys cycling for exercise and commuting.
[B] His city has limited bike lanes, making some routes unsafe.
[C] He recently bought a new car that he rarely drives.
[D] Jamal works long hours and sometimes struggles to find time for exercise.
[E] The local bike shop is offering a discount on electric bikes this month.
[F] Friends who own electric bikes say they make commuting faster and less tiring.
[G] His apartment building has limited storage space for bicycles.
Question 1: Line A is
a. Positively relevant
b. Negatively relevant
c. Irrelevant
Question 2: Line B is
a. Positively relevant
b. Negatively relevant
c. Irrelevant
Question 3: Line C is
a. Positively relevant
b. Negatively relevant
c. Irrelevant
Question 4: Line D is
a. Positively relevant
b. Negatively relevant
c. Irrelevant
Question 5: Line E is
a. Positively relevant
b. Negatively relevant
c. Irrelevant
Section 2: Getting Personal
Critical thinking requires separating a person’s argument from the person themselves. While
we’re wired to evaluate people, this can get in the way of evaluating logic. Review pages 125–
130 before starting.
Passage:
[A] Don’t subscribe to StreamPlus — the CEO wears designer suits and obviously doesn’t care
about regular people.
[B] Also, their most popular competitor, FlixZone, has had a few outages, so maybe all
streaming services are unreliable.
[C] StreamPlus claims that its algorithm recommends the best shows, but you are sure to get
viruses that will steal your identity
[D] StreamPlus’s low prices are just designed to rope you in. Later, they will increase prices.
[E] Try CineWorld instead — sure, it loads more slowly sometimes, but at least it didn’t crash
during last night’s premiere.
Question 6: Line A is
a. Ad hominem
b. Attacking the motive
c. Look who’s talking (tu quoque)
d. Two wrongs don’t make a right
e. Scare tactics
Question 7: Line B is
a. Ad hominem
b. Attacking the motive
c. Look who’s talking (tu quoque)
d. Two wrongs don’t make a right
e. Scare tactics
Question 8: Line C is
a. Ad hominem
b. Attacking the motive
c. Look who’s talking (tu quoque)
d. Two wrongs don’t make a right
e. Scare tactics
Question 9: Line D is
a. Ad hominem
b. Attacking the motive
c. Look who’s talking (tu quoque)
d. Two wrongs don’t make a right
e. Scare tactics
Question 10: Line E is
a. Ad hominem
b. Attacking the motive
c. Look who’s talking (tu quoque)
d. Two wrongs don’t make a right
e. Scare tactics
Section 3: Changing the Subject
Straw man and red herring fallacies twist arguments or distract from the issue. Read pages 132–
133 before continuing.
Dialogue:
Taylor: We should encourage visitors to use reusable containers instead of disposable plastic at
the beach to reduce pollution.
Morgan: (A) So you want to make everyone bring their own containers and ban ice cream
cones? That’s extreme.
Taylor: (B) No, just suggesting alternatives to single-use plastics for snacks and drinks.
Morgan: But even if we reduce plastics, seagulls will still scatter trash everywhere—it won’t
really solve pollution.
Taylor: (C) Honestly, the bigger issue is that people leave food wrappers behind, which attracts
wildlife. That’s what we should focus on.
Morgan: (D) You’re just trying to change the subject from the real problems, like overcrowded
beaches and insufficient lifeguards.
Taylor: (E) The goal is to reduce plastic waste; that doesn’t mean ignoring other beach
management issues.
Question 11: Line A is
a. Straw man
b. Red herring
c. Neither
Question 12: Line B is
a. Straw man
b. Red herring
c. Neither
Question 13: Line C is
a. Straw man
b. Red herring
c. Neither
Question 14: Line D is
a. Straw man
b. Red herring
c. Neither
Question 15: Line E is
a. Straw man
b. Red herring
c. Neither
Section 4: Fallacies of Evidence
These fallacies involve improper use or interpretation of evidence. Read pages 143–154 before
doing this section.
Dialogue:
Lee: I think installing smart thermostats in our apartment building could save energy and reduce utility
bills.
Jordan: (A) If we install a few smart thermostats, soon every appliance will be automated, and we’ll lose
control over everything in our homes!
Lee: That’s not the case. Smart thermostats can be managed individually and don’t take over other
devices.
Jordan: (B) If smart thermostats really saved energy, don’t you think all buildings would already have
them? don’t save energy.
Lee: Studies show that smart thermostats generally help reduce energy usage when programmed
correctly.
Jordan: (C) Last month, my neighbor installed a smart thermostat and the heating bill went up, so these
devices clearly
Lee: (D) So either we don’t install anything, or our building will be fully automated and out of control
Jordan: (E) A few people I know who installed smart devices have had constant tech problems, so all
smart home tech must be unreliable.
Question 16: Line A is
a. Appeal to ignorance
b. Post hoc fallacy
c. Hasty generalization
d. Slippery slope
e. False alternative
Question 17: Line B is
a. Appeal to ignorance
b. Post hoc fallacy
c. Hasty generalization
d. Slippery slope
e. False alternative
Question 18: Line C is
a. Appeal to ignorance
b. Post hoc fallacy
c. Hasty generalization
d. Slippery slope
e. False alternative
Question 19: Line D is
a. Appeal to ignorance
b. Post hoc fallacy
c. Hasty generalization
d. Slippery slope
e. False alternative
Question 20: Line E is
a. Appeal to ignorance
b. Post hoc fallacy
c. Hasty generalization
d. Slippery slope
e. False alternative