1 / 18

Fallacies of Presumption, Ambiguity, and Grammatical Analogy

Fallacies of Presumption, Ambiguity, and Grammatical Analogy. Fallacies of Presumption Overview. Key characteristic: Premises presume what they claim to prove. Begging the Question: Definition.

kumiko
Télécharger la présentation

Fallacies of Presumption, Ambiguity, and Grammatical Analogy

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Fallacies of Presumption, Ambiguity, and Grammatical Analogy

  2. Fallacies of PresumptionOverview • Key characteristic: Premises presume what they claim to prove.

  3. Begging the Question:Definition • Occurs when an arguer uses some form of phraseology to conceal a key premise that may be unsupported by argument

  4. Begging the Question:Examples • Murder is morally wrong. This being the case, it follows that abortion is morally wrong. • Comment: Ignores the fact that the argument doesn’t prove that abortion is murder, which is the real point of controversy.

  5. Complex Question:Definition • Occurs when a single question that is really two (or more) question is asked and a single answer is then applied to both questions

  6. Complex Question:Examples • Do you still beat your wife? • Comment: However you answer this question, it commits you to saying that you engaged in this behavior in the past. • Have you stopped cheating on exams? • Comment: Supposes that you have cheated in the past.

  7. False Dichotomy:Definition • Occurs when the arguer assumes there are only two alternatives when in fact there are more than two.

  8. False Dichotomy:Example • Either you buy only American-made products or you don’t deserve to be called a loyal America. Yesterday you bought a new Toyota. It’s clear you don’t deserve to be called a loyal American! • Comment: The person may still be a very loyal citizen.

  9. Suppressed Evidence:Definition • Ignores some important piece of evidence that: 1) outweighs the presented evidence 2) entails a very different conclusion. • Difficult to detect because you must know about the details of the case.

  10. Suppressed Evidence:Example • Used car salesman: “This car is a great value. It’s clean and has low mileage.” • Comment: The salesman may not be telling you that the car had been in a serious crash.

  11. Equivocation:Definition • Occurs when the conclusion of an argument depends on a word or phrase that is used (explicitly or implicitly) in two different senses. • Such arguments are either invalid or have a false premise.

  12. Equivocation:Example • Some triangles are obtuse. Whatever is obtuse is ignorant. So some triangles are ignorant. • Comment: “Obtuse” is used in two ways: • Greater than 90 degrees • Not smart

  13. Amphiboly:Definition • Occurs when the arguer misinterprets a statement that is syntactically or grammatically ambiguous • and then proceeds to draw a conclusion based on this faulty interpretation.

  14. Amphiboly:Example • Professor Johnson said that he will give a lecture about heart failure in the biology lecture hall. It must be the case that a number of heart failures have occurred there recently. • Comment: The phrase “in the biology lecture hall” should be placed immediately after “lecture” instead of “heart failure.”

  15. Composition:Definition • This fallacy occurs when the conclusion of an argument depends on the erroneous transference of an attribute from the part of something to the whole.

  16. Composition:Example • Each sentence in this composition is well-written. Therefore the whole essay is well-written. • Comment: It doesn’t follow from the fact that each individual sentence is well written that the whole essay is well written.

  17. Division: Definition • Occurs when the conclusion of an argument depends on the erroneous transference of an attribute form a whole (or a class) onto its parts (or members).

  18. Division: Example • America is a wealthy country. Bill Smith is an American, therefore he is wealthy. • Comment: Even though it is true that the country as a whole is wealthy, it doesn’t follow that each individual in the country is a wealthy individual.

More Related