Inductive and Deductive Reasoning: Fallacies Lesson

Week 2

Week 2: April 5 - 11

Each weekly folder contains a list of assignments to help you stay organized.

Due Wednesday, April 7:

Read Chapter 5 of Practical Argument

Read the Inductive and Deductive Reasoning Supplemental Resource

Fallacies Lesson

2.1 Discussion Topic

2.2 Assignment

2.3 Discussions

Due Sunday, April 11:

Draft a minimum of two responses for the 2.1 Discussion topic.

Rhetorical Analysis Essay (submit in Week 1 folder)

Inductive and  Deductive Reasoning

 Inductive vs DeductiveReasoning_2011(1).docx

(Source: Tammy Peery)

Fallacy Examples


Avoiding Fallacies and Clichéd Arguments

Fallacies exist in two types:

1. Fallacies of matter

2. Fallacies of reasoning

Fallacies of matter occur when the writer has provided false information, a claim that is unsupported by facts and evidence or a half- truth.

In three cases, a statement does not require proof:

1. Self-evident statements

2. Accepted definitions

3. Statements that a minimally informed person would know

Fallacies of reasoning are flaws in logic.

1. Faulty Generalization - Assumptions are made based on insufficient evidence or an unrepresentative sample. Stereotypes are a type of hasty generalization. This is often referred to as leaping to a conclusion or a hasty generalization.


We'd better watch that man wearing the turban. He could be a terrorist.

Football linemen are athletic, but not intelligent.

I read in Newsweek that doctors' salaries are really high; my neighbor, Dr. Smith, must be really rich. Faulty generalizations can also occur with a statistical sample that is unrepresentative.

Faulty generalizations can also happen when we use authorities improperly: the authority itself might be at fault or we might misquote, misinterpret or take information out of context.

2. Post hoc ergo propter hoc (Faulty Causal Generalization)- These are commonly seen in cause/effect argument. This fallacy is an error in chronology; simply because one event occurred before another, the speaker assumes that it caused it.


Studies have conclusively proved that 85% of people who died in car wrecks in the last year ate ice cream within one month of the accident. This figure indicates that ice cream equals vehicle mortality.

I told you the seers were right. Didn't the volcano stop erupting after we tossed in those virgins?

3. Non sequitur - This fallacy occurs when no logical relationship exists between two ideas, yet the author represents it as such.


Although it has been demonstrated that inner city clinics need better facilities, I will not support appropriations for improving their facilities as long as doctors charge such exorbitant fees.

4. Faulty Analogy - A faulty or false analogy occurs when the analogy focuses on irrelevant or inconsequential similarities between circumstances instead of focusing on the pertinent similarities.

Example of a valid analogy:

A war in the Philippines would be disastrous. Our soldiers had a terrible time fighting in the jungles of Vietnam, and the terrain around Manila is even worse.

Example of a faulty analogy:

If we decide to attack the Philippines, we should probably do it in January. In 1991, we attacked Iraq in January, and look how well that turned out.

5. Begging the Question - This fallacy involves circular reasoning. The writer assumes the validity of an unproven premise, expecting the reader to take it as a fact:


Because the death penalty deters murderers, it should be made the mandatory sentence for convicted killers.

My client would not steal because he is an honest man. Begging the question can also occur more subtlety by word choice. Examples:

We don't want any controversial speakers influencing the students. This creeping socialism won't fool the American people.

Red flag words for begging the question are: obviously, of course, everyone knows, really, unquestionably. Obviously, upon seeing these words in a text, you should question if the statements are, of course, really unquestionable.

6. Ad hominem - This fallacy assumes that irrelevant character flaws should invalidate an individual's position on an issue. We see this a lot in politics.


How can this person be Commander in Chief of our armed forces? He experimented with marijuana in college.

How can we trust the Senator's work on the economy when he has been cheating on his wife for years?

Do not confuse this fallacy with simple name calling. That's just being a jerk. Also, focus on the word "irrelevant". Character defects can make a difference in policy decisions. If the Senator in question is passing laws on marriage reform, then, yes, we could call his marital history into question.

7. Ad populum - This fallacy appeals to irrational fears and prejudices in the reader to provoke them into action. Although emotional appeals are a necessary part of persuasion, appealing to irrational fears and biases is unethical when the issues become clouded or emotion begins to cloud reason. This fallacy relies on buzzwords that cue certain emotional responses: patriotism, Homeland, godlessness, reactionary, socialism...


Curtailing freedom of speech may be necessary to maintain the national security of our homeland.

Although Medicare is an important program for the elderly and the infirm, increasing Medicare eligibility is nothing more than a liberal plan to promote big government and socialized medicine.

8. Red Herring - The red herring is a diversionary tactic. The speaker avoids the actual issue and instead focuses the reader on an irrelevant, distracting idea; it is changing the subject.


You accuse me of cheating on my taxes, but who doesn't cheat a little bit?

So what if the general did lose that battle? Think of all the glorious victories of the past.

It may be true that I failed the test, but think of all the other important, good things I did this week.

9. Complex Question - This fallacy occurs when the speaker asks a question that is impossible to answer without incrimination. This is also known as a leading question.


When did you stop beating your wife? Why did you steal the money?

The complex question occurs frequently in legislation when smaller, rider bills are attached to larger important issues.

10. False dilemma - Similar to the complex question, the false dilemma or false dichotomy forces the reader into making a choice between two options as if no other options exists It also implies a logical relationship where none exists.


If you are not for the war, you are against the troops. I support the war because I support our troops.

I am pro-choice because to be otherwise would be antiwoman.

11. Straw Man - The speaker builds an intentionally weak or erroneous summary of the opponent's argument to make it easier to refute it. By defeating this fictional version of the opponent's argument, the speaker can claim victory despite the fact that the speaker has not actually dealt with the issues at hand.


Those who want to adopt campus-wide codes against sexist, racist and homophobic speech believe that they can prevent such kinds of

speech. As noble an idea as this is, realize the idea is practically impossible. Prejudice, a basic component of human nature, will not be eliminated with the passage of new riles and laws. Those who would try to limit free speech on campus would curtail a vital part of the American Constitution in the name of a pipe dream.

The problem with anti-porn feminists is that they think sex is bad because men are evil. They tell us that any sexual relationship between a man and a woman will demean the woman and enforce the patriarchal hegemony of the man. This idea ignores the fact that a lot of men really do respect and care for women.

12. Dicto Simpliciter - This fallacy assumes that because something is good in general, it must also be good in a specific circumstance.


Milk is good for you, so everyone should drink milk. It is good to date, therefore you should date me.

13. Bandwagoning - This fallacy asks the reader to assume that the reader should believe in something based on the idea that everyone else already does. It's an appeal to peer pressure. This is very similar to the Ad Populum appeal in that it relies on the audience's emotional desire to belong.


Don't be the last person in your neighborhood to make the switch to Kern's Lawn Care. Don't be the only one who doesn't care about the appearance of the neighborhood.

Support for anti-guns in school legislation will become increasinly hard to maintain. A recent poll suggests that 90% of Americans support the idea of teachers and students carrying guns.

14. Appeal to Ignorance - This fallacy makes the assumption that something is true as long as it has not been proved to be false.


UFO's must be alien spacecraft because scientists have not proved that they are not.

Dolphins have not been negatively effected by the BP oil spill because no evidence has scientifically shown that it is true.

15. Thought terminating cliché - This fallacy seeks to quell any cognitive dissonance in the audience by bringing up a piece of folk wisdom or an often repeated statement that ends all arguing with a platitude instead of a resolution. George Orwell played around with the concept in his "Newspeak" in Nineteen Eighty-Four.


When guns are outlawed, only outlaws will have guns. Make love not war.

This fallacy renders critical thinking not only unnecessary but non-existent.

Source Image:  "Man  Standing  Near  Body  of  Water"   by  Silver  Works licensed as free to use no attribution required

Optional Supplemental Resource: "Love Is a Fallacy"  (adapted from Max Shulman's short story)

Love  Is a Fallacy

User: n/a - Added: 4/18/13

Watch Video

This video is intended to be  a fun  way to deepen your understanding of fallacies! Enjoy!

Do you recognize the Black  Panther star in this short lm?