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Workshop: Logical Fallacy

Portland State University

Jenny Woodman

on 20 July 2015

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Transcript of Workshop: Logical Fallacy

Creating a sound argument
Logical Fallacies
According to the Owl Purdue Website . . .
What is a logical fallacy?
The Slippery Slope
This fallacy occurs when we make connections between the points in our arguments to say that over the course of time, if A happens, then B, and so on, then z will be the final result.
The Hasty Generalization
A conclusion is drawn from little or no evidence. Sometimes we make sweeping and presumptive generalizations that have no factual basis in reality.
Post hoc ergo propter hoc
If something happens after another thing, it is assumed that the first thing was the cause.
Genetic Fallacy
"A conclusion is based on an argument that the origins of a person, idea, institute, or theory determine its character, nature, or worth" (Owl Purdue).

Sometimes we have a tendency to reject an idea because of the source rather than any inherent flaw in the idea.
Begging the claim
The writer sticks the conclusion into the argument without proof and hopes it
works . . .
"Fallacies are common errors in reasoning that will undermine the logic of your argument. Fallacies can be either illegitimate arguments or irrelevant points, and are often identified because they lack evidence that supports their claim"
We can see this all the time in political debates. . .
If Obama makes automatic weapons illegal, the government will eventually make all guns illegal, therefore we should not support a ban on automatic weapons.
That math class was really hard, therefore all math classes are really hard.
After the fact, therefore because of the fact
Roosters crow just before the sun rises. Therefore, roosters crowing cause the sun to rise.
Or how about this one . . .
Most divorced couples go to see a therapist before they separate. Therefore going to see a therapist will increase the chances that you will get a divorce.
Here's a great example of this one:

Eugenics (the study of human improvement by genetic means) was created in Germany during WWII. Therefore, eugenics is a bad thing.

Maybe it is, but the statement provides no evidence to support the claim.
From the owl website:

"Filthy and polluting coal should be banned."

Well, yes it should, but you haven't proved a thing!
Circular Argument
Simply repeating your claim does not count as providing evidence.
'President Reagan was a great communicator because he had the knack of talking effectively to the people.'
The argument is reduced to only having two choices. Essentially, things are oversimplified so that the range of viable solutions is incredibly narrow and shortsighted.
You are either for us or against us!
(If I wasn't before you said that, I am now!)
Ad hominem
This fallacy occurs when the writer attacks the character of the person or group, rather than the actions
The Republican party's ideas fail because they are all jerks.
Ad populum
"This is an emotional appeal that speaks to positive (such as patriotism, religion, democracy) or negative (such as terrorism or fascism) concepts rather than the real issue at hand" (Owl Purdue).
“The fact that the majority of our citizens support the death penalty proves that it is morally right.”
The Red Herring
Throwing something irrelevant into the argument to distract and avoid the weaknesses in your own position.
Reporter: "Mr. President, your opponent, Walter Mondale is considerably younger than you. Do you think that with the threat of nuclear war, age should be an issue in this campaign?"

President Reagan: "Not at all. I am not going to exploit my opponent's youth and inexperience."
The Straw Man
Rather than answer your opposition's claims honestly, oversimplify (often incorrectly) & attack their argument
Republicans want to end social programs because they hate poor people.
Moral Equivalence
This one compares a minor problem to a serious crime & vice versa.
Mandatory seatbelt laws are fascist.
A Few Final Tips for Organizing Your Paper
Title page
The title page should include:
Your paper's title
Your Name
Institutional Affiliation
The Abstract
Your paper begins here with an introduction. This is where you introduce the problem, your overarching question, and/or why this matters. The APA manual states that "a good introduction answers these questions in just a few pages and, by summarizing the relevant arguments and past evidence, gives the reader a firm sense of what was done and why" (2009, p. 27).
After you have walked the reader through all of the important details of your research, (in other words, presented the ideas and works of others in a concise manner), it is time for you to interpret the information and explain how the materials presented relate to your original research question and thesis.

Conclude the discussion with an explanation of how this all fits together and suggest a question for future research on the subject.
Body of Your Paper
In addition to your research and reflections, it is really important to include the thoughts and ideas of those that don't agree with your thesis. If you are open and transparent with criticism, it will give your argument more credibility. Be sure to answer the critics claims with logic and reasoning.
Thanks for sticking with this, and email me or schedule office hours if:
you have any questions
you get stuck, or
you have any funny jokes to share
Happy Writing!!!
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