Chapter 5: Logical Fallacies §

I. Logical Fallacy §

Fallacious Arguments are arguments which contain one more more Logical Fallacy.

Logical Fallacy (fallacy): arguments which contains mistakes in reasoning.

Divided into two:

• Fallacies of relevance premises logically unrelated/irrelevant to conclusion
• Fallacies of insufficient evidence: premises related but provide insufficient evidence to prove the conclusion

II. The Concept of Relevance §

💡 A statement is relevant if it counts either for or against that other statement

Applies for both Deductive and Inductive

Positively Relevant §

if the statement counts in favor of another statement

• Even making the conclusion slightly more probable than before is positively relevant

Concepts:

• Factually false statements can also be positively relevant
• statements are positively relevant when the context relates it to one another

  • Contextual statement could turn two NR statements to a PR statement

    Martina partied all night last night. However, Martina was valedictorian of her high school class. Therefore, she will do well on her critical thinking test this morning.

Negatively Relevant §

if the statement counts against another statement

• If the premise is true the conclusion is more likely to be false

Logical Irrelevance §

• if the statement neither count for nor against another statement
• The premise doesn’t related to the conclusion in any way

III. Fallacies of Relevance §

💡 Argument with Premises that are irrelevant to the conclusion

1. Personal Attack (Ad Hominem) §

Reject someone claim or argument and attacking the person rather than their argument or reasoning

• A person’s character does not reflect their argument’s strength

(Exception)

• A personal characteristic that is relevant to the conclusion is not fallacious however

  If a person’s character helps to prove the point it is a good argument

2. Attacking the Motive §

Criticizing a person’s motivation for offering the argument rather than examining the argument’s strength itself.

• Even if a person is not in position to raise that argument, the argument still needs to be evaluated for its reasoning, not it’s arguer’s motive.

Common Pattern:

1. X is biased or has questionable motives.
2. Therefore, X’s argument or claim should be rejected.

(Exception)

If the arguer has obvious bias that has reflected obvious lies in their argument. It’s not the critique to the argument but to the motive of the arguer.

3. Look Who’s Talking §

Reject someone claim or argument as they are a hypocrite who doesn’t practice what they preach

• Reasons need to be examined rather than invalidating an argument based on the arguer

Common Pattern:

1. X fails to follow his or her own advice.
2. Therefore, X’s claim or argument should be rejected.

(Exception)

Pointing out someone is a hypocrite and accepting the behavior is wrong is not a fallacy

4. Two Wrongs Make a Right §

Arguer attempts to justify a wrongful act by claiming some other acts are just as bad or worse.

(Exception)

• The justification must be sufficient and logical enough to conjure up a the response

  • Two wrongs make a right could be not fallacious if it’s a justified response Ex:

    Police officer: Why did you spray this man with pepper spray? You: Because he attacked me with a knife. I did it in self-defense.

-Difference between- §

Look Who’s Talking

The look who’s talking fallacy always involves a charge of hypocrisy or failing to practice what one preaches; the two wrongs make a right fallacy often does not.

Two Wrongs Make a Right

The two wrongs make a right fallacy always involves an attempt to justify an apparently wrongful act; the look who’s talking fallacy often does not.

Arguments can commit both ‘Look Who’s Talking’ and ‘Two Wrongs Make a Right’ Fallacy

5. Scare Tactic §

arguer threaten harm to the listener or reader if they don’t accept the arguer’s conclusion.

• The threat doesn’t relate any way to the conclusion
• Threats can be non-physical

(Exception)

• If the threat is relevant to the conclusion it is not a fallacy
• If it is a statement instead of an argument it’s not a fallacy

6. Appeal to Pity §

Inappropriately attempt to evoke empathy, pity, or compassion to the listener to make irrational choices.

• The premises are not in any way relevant to the conclusion

(Exception)

• If the premise is relevant and helps the conclusion it is not fallacy.

7. Bandwagon Argument §

to argue something is true because many people accept that it is so.

• Many people believing something does not mean it’s factually true.

Common Pattern:

1. Everybody (or a select group of people) believes or does X.
2. Therefore, you should believe or do X, too.

(Exception)

• If the people’s belief is understandable, logical, and relevant to the conclusion

  All the villagers I’ve talked to say that the water is safe to drink. Therefore, the water probably is safe to drink. (Inductive)

8. The Straw Man Fallacy §

arguer distort or misinterpret an opponent’s argument to more easily attack it.

• Attempt to take opponent’s argument to the extreme, out of context, to say it’s not logical stance.

Common Pattern:

1. X’s view is false or unjustified (but where X’s view has been unfairly characterized or misrepresented).
2. Therefore, X’s view should be rejected.

9. The Red Herring §

to distract the audience by bringing up an irrelevant issue and implying the argument is proven by the irrelevant issue.

Changing the topic isn’t fallacy (Exception)

• To evade and ignore an issue. Not bringing up irrelevant point to argue

-Differences between- §

The Straw Man Fallacy

The straw man fallacy always involves misrepresenting another person’s argument or claim; the red herring fallacy often does not.

The Red herring

The red herring fallacy always involves changing or evading the issue; the straw man fallacy often does not.

10. Equivocation §

is committed when a keyword with multiple meanings is used to prove a point to be true even though its not logical

• Ex

  It is a crime to smoke grass. Kentucky bluegrass is a grass. Therefore, it is a crime to smoke Kentucky bluegrass. (first grass meant marijuana, while the second grass meant lawn grass)

Common Pattern:

1. All A’s are B’s.

2. C is an A (Wrong) | C is a D (Corrected)

3. Therefore C is a B

(A is a double meaning term)

11. Begging the Question §

Rephrasing and restating the conclusion as the premise

• Ex:

  Bungee-jumping is dangerous because it’s unsafe.

Circular Reasoning or Arguing in a Circle

• The conclusion is stated as true and acts as one of the premises.
• A because B, B because A.

Summary §

💡 A. Personal attack: Arguer attacks the character of another arguer. B. Attacking the motive: Arguer attacks the motive of another arguer. C. Look who’s talking: Arguer attacks the hypocrisy of another arguer. D. Two wrongs make a right: Arguer tries to justify a wrong by citing another wrong. E. Scare tactics: Arguer threatens a reader or listener. F. Appeal to pity: Arguer tries to evoke pity from a reader or listener. G. Bandwagon argument: Arguer appeals to a reader’s or listener’s desire to be accepted or valued. H. Straw man: Arguer misrepresents an opponent’s position. I. Red herring: Arguer tries to distract the attention of the audience by raising an irrelevant issue. J. Equivocation: Arguer uses a key word in two or more different senses. K. Begging the question: Arguer assumes the point to be proven.