Understanding Logical Fallacies
Directed Learning Activity—Critical Thinking 05
Essential Question
What is a logical fallacy and how do I spot fallacies in a visual?
Purpose
This activity is designed to strengthen your knowledge of five common logical fallacies and how to
recognize them in literary works.
This DLA should take approximately 30 to 45 minutes to complete.
Directions
Read the information below taken directly from “Fallacies” by The Writing Center, University of North
Carolina at Chapel Hill, and Beyond Feelings: A Guide to Critical Thinking by Vincent Ryan Ruggiero, then
do the activity on the next page. You only need to print the activity page.
Hasty Generalization
Definition: Making assumptions about a whole group or range of cases based on a sample that is
inadequate (usually because it is atypical or too small). Stereotypes about people (“librarians are shy
and smart,” “wealthy people are snobs,” etc.) are a common example of the principle underlying hasty
generalization.
Example: “My roommate said her philosophy class was hard, and the one I’m in is hard, too. All
philosophy classes must be hard!” Two people’s experiences are, in this case, not enough on which to
base a conclusion.
Slippery Slope
Definition: The arguer claims that a sort of chain reaction, usually ending in some dire consequence, will
take place, but there’s really not enough evidence for that assumption. The arguer asserts that if we
take even one step onto the “slippery slope,” we will end up sliding all the way to the bottom; he or she
assumes we can’t stop partway down the hill.
Example: “Animal experimentation reduces our respect for life. If we don’t respect life, we are likely to
be more and more tolerant of violent acts like war and murder. Soon our society will become a
battlefield in which everyone constantly fears for their lives. It will be the end of civilization. To prevent
this terrible consequence, we should make animal experimentation illegal right now.”
False Analogy
Definition: Many arguments rely on an analogy between two or more objects, ideas, or situations. If the
two things that are being compared aren’t really alike in the relevant respects, the analogy is a weak
one, and the argument that relies on it commits the fallacy of weak analogy.
Example: “Guns are like hammers—they’re both tools with metal parts that could be used to kill
someone. And yet it would be ridiculous to restrict the purchase of hammers—so restrictions on
purchasing guns are equally ridiculous.”
Either/Or (False Dichotomy)
Definition: In false dichotomy, the arguer sets up the situation so it looks like there are only two choices.
The arguer then eliminates one of the choices, so it seems that we are left with only one option: the one
the arguer wanted us to pick in the first place. But often there are really many different options, not just
two—and if we thought about them all, we might not be so quick to pick the one the arguer
recommends.
Example: “Caldwell Hall is in bad shape. Either we tear it down and put up a new building, or we
continue to risk students’ safety. Obviously we shouldn’t risk anyone’s safety, so we must tear the
building down.”
Irrational Appeal to Tradition
Definition: An irrational appeal urges maintaining the tradition merely because we’ve always done so.
Example: For many years, doctors refused to accept indisputable evidence that washing their hands
between patients curtailed the spread of disease simply because washing hands between patients was
not part of the medical tradition (Ruggiero 131).
Exercise
Now that you have read about five common logical fallacies, read the excerpts below, indicate which
fallacy is at play (if any), and then explain why.
1) “That’s all there is,” my father said. “War and peace with nothing in between. It’s always one or
another.” (Taken from “Because My Father Always Said. . .” by Sherman Alexie)
2) Scout says, “Until I feared I would lose it, I never loved to read. One does not love breathing.”
(Taken from To Kill a Mockingbird by Harper Lee)
3) “Damn pack of crazy fools,” says Old Man Warner after being told that some people want to
give up the lottery. “Next thing you know, they’ll be wanting to go back to living in caves,
nobody work any more. Live that way for awhile.” (Taken from “The Lottery” by Shirley Jackson)
4) “There’s always been a lottery,” asserts Old Man Warner in defense of keeping the lottery.
(Taken from “The Lottery” by Shirley Jackson)
5) As my white friends revived me and prepared to take me to the emergency room where doctors
would later diagnose my diabetes, the Chicano teacher ran up to us. “Hey,” he said. “What’s
that boy been drinking? I know all about these Indian kids. They start drinking real young.”
(Taken from “Indian Education” by Sherman Alexie)
Review your answers with an instructor or tutor in the Virtual Writing & Reading Center. Be sure you can
answer the essential question above.
—-
Understanding Logical Fallacies—Critical Thinking Directed Learning Activity 05
The Crucial Question
What is a logical fallacy, and how can I identify one in a visual?
Purpose
This activity is intended to improve your understanding of five basic logical fallacies and how to avoid them.
They can be found in literary works.
This DLA should take between 30 and 45 minutes to finish.
Directions
Read the information below, which was taken directly from “Fallacies” by The Writing Center at the University of North Carolina.
Carolina at Chapel Hill, as well as Vincent Ryan Ruggiero’s Beyond Feelings: A Guide to Critical Thinking,
Carry out the exercise on the next page. The only thing you need to do is print the activity page.
Excessive Generalization
Making conclusions about a whole group or range of situations based on a small sample size
inadequate
