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Ibn Zohr University�ENSA- Agadir�Dr. Mohamed NouhiAdvanced Composition/ CommunicationLogic Fallacies��

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An argument consists of:

  • a premise
  • a claim
  • a conclusion

A Logical fallacy is:

  • a serious defunct in reasoning
  • There is no validity in logic because the components of the argument are inconsistent

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False Dilemma

  • It is also Known as: Black & White Thinking.
  • 1. Either 1+1 =4 or 1+1=12 .
  • 2. It is not the case that 1+1 = 4.
  • 3. Therefore 1+1 =12.

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Red Herring

It is also Known as: Smoke Screen, Wild Goose Chase

A Red Herring is a fallacy in which an irrelevant topic is presented in order to divert attention from the original issue. The basic idea is to “win” an argument by leading attention away from the argument and to another topic. This sort of “reasoning” has the following form:

1. Topic A is under discussion.

2. Topic B is introduced under the guise of being relevant to topic A (when topic B is actually not relevant to topic A).

3. Topic A is abandoned.

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Argumentum ad hominem 

  • A serious mistake in reasoning. Instead of developing an argument, you attack the person who is the source of information.
  • It is abusive since it is “against the man” or “against the person who is making the claim, because of his circumstances, or his actions .
  • It is associated with Poisoning the Well trying to discredit what a person might later claim by presenting unfavorable information (be it true or false) about the person.

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Ad Verecundiam

  • Appeal to Authority, Misuse of Authority, Irrelevant Authority.
  • It is committed when the person in question is not a legitimate authority on the subject, or S/he is not an expert, or qualified to make reliable claims in subject
  • In such cases the reasoning is flawed because the claim does not provide any rational reason to accept the claim as true.

  

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Argumentum ad misericordiam (or appeal to pity)

  • Appeal to Emotion: It incite emotions in people does not serve as evidence for a claim
  • Most political speeches are aimed at generating feelings in people so that these feelings will get them to vote or act a certain way. In the case of advertising, the commercials are aimed at evoking emotions that will influence people to buy certain products.
  • Pity does not serve as a valid argument.

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Appeal to Novelty

  • Appeal to the new: everything new is better than the old.
  • Correctness and validity is never associated with the newness of an item, an idea, concept, or a product….
  • It is the opposite of the Appeal to Tradition or the Appeal to the past ,Old Ways are Best

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Begging the Question

  • It is also Known as: Circular Reasoning, Reasoning in a Circle
  • Bill: “God must exist.”
  • Jill: “How do you know.”
  • Bill: “Because the Bible says so.”
  • Jill: “Why should I believe the Bible?” Bill: “Because the Bible was written by God.”

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Confusing Cause and Effect

  • This fallacy is committed when a person assumes that one event must cause another just because the events occur together. More formally, this fallacy involves drawing the conclusion that A is the cause of B simply because A and B are in regular conjunction

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Guilt by Association

It is also Known as: Bad Company Fallacy

You reject the claims simply because this would put you in the company of people you dislike.

The person will be rejecting the claim based on how he thinks or feels about the people who hold it and because he does not want to be associated with such people.

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Hasty Generalization

  • It is known also as Biased Statistics, Loaded Sample
  • Making assumptions about a whole community based on a small inadequate samples
  • Creating a general rule based on a single case

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Argumentum ad numerum (appeal to numbers).

  • It is similar to  argumentum ad populum.
  •  This fallacy is the attempt to prove something by showing how many people think that it's true. But no matter how many people believe something, that doesn't necessarily make it true or right.

Appeal to common belief: Most people believe that… / Most people approve of…

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The Horse Laugh

  • Appeal to Ridicule or Appeal to Mockery.
  • ridicule or mockery is substituted for evidence in an “argument.”

  • The argument is reduced to absurdity:

“Those crazy conservatives! They think a strong military is the key to peace! Such fools!

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Logic Chopping

(also known as: quibbling, splitting-hairs, trivial objections)

Description: Using the technical tools of logic in an unhelpful and pedantic manner by focusing on trivial details instead of directly addressing the main issue in dispute.  Irrelevant over precision.

For example, Paul is avoiding the request for assistance by attempting to make a deep philosophical issue out of a simple request:

John: Can you please help me push my car to the side of the road until the tow truck comes?

Paul: Why push it to the side of the road?  Why not just leave it?

John: It is slowing down traffic unnecessarily where it is.

Paul: Many things slow down traffic—do you feel you need to do something about all them?

John: No, but this was my fault.

Paul: Was it really? Were you the direct cause of your car breaking down?

John: Are you going to help me move this damn car or not?

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Argumentum Ad Ignorantium: It is also known as the either/or fallacy.

For instance, one might mistakenly argue that, since the Newtonian theory of mathematics is not one hundred percent accurate, Einstein’s theory of relativity must be true. Perhaps not. Perhaps the theories of quantum mechanics are more accurate, and Einstein’s theory is flawed. Perhaps they are all wrong. Disproving an opponent’s argument does not necessarily mean your own argument must be true automatically.

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Package-Deal Fallacy: It is also known as: false conjunction

 Assuming things that are often grouped together must always be grouped together, or the assumption that the ungrouping will have significantly more severe effects than anticipated.

Example:

If indoor smoking laws are passed for bars, the bars will go out of business since people who drink, smoke while they drink.

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Stacking the Deck: In this fallacy, the speaker "stacks the deck" in her favor by ignoring examples that disprove the point, and listing only those examples that support her case. This fallacy implies deliberate deception to exclude or omit relevant examples from a sample. For instance:

Jack asserts, “The Scottish national character is brave and patriotic. No Scottish soldier has ever fled the field of battle in the face of the enemy.”

Nancy objects, “Ah, but what about Lucas MacDurgan? He fled from German troops in World War I.”

Jack retorts, “Well, obviously he doesn’t count as a true Scotsman because he did not live up to Scottish ideals, thus he forfeited his Scottish identity.”

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Division:. It is the misapplication of deductive reasoning. It argues falsely that what is true of the whole must be true of individual parts. Such an argument concludes that because Mr. Smith is an employee of an influential company, he must be an influential individual. Another fallacy of division attributes the properties of the whole to the individual member of the whole. "Microtech is an immoral business incorporation that engages in unethical trading schemes. Susan Jones is a janitor at Microtech. She must be an immoral individual.“

This fallacy is the reverse of Composition since it applies the properties of the parts of the whole to the properties of the whole itself.

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Non Sequitur: It is also known as Invalid Inference. Latin for "It does not follow. It is “a statement that is not connected in a logical or clear way to anything said before it. For example:

People generally like to walk on the beach.  Beaches have sand.  Therefore, having sand floors in homes would be a great idea!

Example 2:

Mac Donald has the greatest food in town.  Mac Donald was voted number 1 by the local paper.  Therefore, Jones, the owner of Mac Donald , should run for president of the United States.

A major illustration of Non Sequitur is post hoc, ergo propter hoc: Latin for "It happened after, so it was caused by." Similar to a non sequitur, but time dependent. (e.g. She got sick after she visited China, so something in China caused her sickness.) Perhaps her sickness derived from something entirely independent from China.