1. 1 Discourse Fallacies PSC 202 Fall 2004 Prof. Northrup

2. 2 Formal and Informal Fallacies Fallacy Formal fallacy Informal fallacy

3. 3 Informal Fallacies – Four Types I. Fallacies of Ambiguity II. Fallacies of Relevance III. Fallacies of Presumption IV. Fallacies of Weak Induction

4. 4 I. Fallacies of Ambiguity (5) Based on ambiguous use of terms or phrases That is, the term or phrase can have more than one meaning

5. 5 I. 1) Equivocation A shift in meaning of a word in one premise to the next, or from a premise to the conclusion E.g. All cats are small domestic animals All lions are cats So, all lions are small domestic animals Can be done conversationally

6. 6 I. 2) Amphiboly Like equivocation, but applies to a phrase The meaning of the phrase shifts Example: Methodists and “doubt” Leader: Rise and greet the morning. People: Cast off your sleep and doubt.

7. 7 I. 3) Accent Occurs when a passage is incompletely quoted or a passage is taken out of context or both Examples: Sound bites Taking only words that support your side

8. 8 I. 4) Division When a claim that is true of an entire class of things is mistakenly applied to a single member of the class, OR A claim that is true of a whole thing is mistakenly applied to a part of a whole Example: state vs. national trends

9. 9 I. 5) Composition The mirror image of division Inferring that a whole or an entire class of objects has certain properties because one of the parts of the whole, or one member of the class, has that property Examples: “Because of hurricane Ivan, there was flooding in Louisiana today.” “The hood of my car is red, so my car is red.”

10. 10 II. Fallacies of Relevance (8) Assume a false premise or reach a conclusion that is not supported by the premises Often used by politicians

11. 11 II. 1) Appeal to Force Argumentum ad baculum An argument includes an implicit but unwarranted or inappropriate threat Consider: “You should make a contribution to the Democratic candidate. After all, you are currently an employee of this company.”

12. 12 Appeal to Force - Caveat Not a fallacy if the threat is legitimate Consider: “Watch your speed. Police use radar.”

13. 13 II. 2) Personal Attack Argumentum ad hominem Occurs when replying to an argument The person, not the argument, is attacked Calling credibility into question

14. 14 Personal Attack continued 1 Tricky – sometimes valid to question E.g. “expert” witness in a trial Example? Campaign strategy of accusing opponent of flip-flopping

15. 15 Personal Attack continued 2 Tu quoque (literally, “you too”) “You do it, why shouldn’t I?” Sarcasm as a response “I see you've set aside this special time to humiliate yourself in public.”

16. 16 II. 3) Mob Appeal Argumentum ad populum Assumption that some type of popular appeal is a sufficient reason to engage in an action or hold a belief Typical forms Inclusion: “Doing x (e.g. voting for this candidate) makes you feel good, so you should do it.” Exclusion: Not doing x excludes you from the norm (of the mob) Appeals to emotion (e.g. Hitler’s speeches) “Family values”?

17. 17 II. 4) Appeal to Pity Argumentum ad misericordium Assumes that suffering is a sufficient reason to engage in an action or hold a belief (e.g. charity call) Possibly valid moral reason but irrational solution Or may not be a cause for pity So must ask two questions: Is there moral force to the claim of suffering Is the solution a good one

18. 18 II. 5) Stereotyping General claim about a group that is false because 1. not true of that group There was a blonde, a red-head and a brunette…” 2. not more true of that group than any other “Red-heads have bad tempers” 3. claim has some validity but not of the group’s making Northern Ireland – Protestant claim that Catholics are lazy because they don’t get jobs Also called the genetic fallacy

19. 19 II. 6) Straw Man When an argument is misrepresented and the misrepresentation is criticized Can be done by claiming that there is an underlying premise that you have now revealed, and it’s wrong Can be done by misrepresenting the conclusion, and then criticizing the conclusion

20. 20 II. 7) Red Herring A response to an argument that confuses the issues, thus causing a distraction from the actual argument Smith factory example Distraction may be a valid concern, but doesn’t address the argument at hand

21. 21 II. 8) Irrelevant Conclusion non sequitur (doesn’t follow) When a conclusion is drawn from an argument not suggested by the premises Obvious example - an invalid deductive argument: All aardvarks are mammals All mammals are vertebrates So, some aardvarks are good pets Hunting example

22. 22 III. Fallacies of Presumption (4) Assumes something that isn’t stated and does so incorrectly assumes the conclusion as a premise assumes that the premises contain all the relevant information while they do not Unlike a deductive argument where the premises entail the conclusion, that is, the premises logically result in the conclusion

23. 23 III. 1) Begging the Question Conclusion is assumed as one of the premises “George Bush is the President because George Bush is President” Different words, same meaning “George Bush is the President of the US, since George Bush holds the highest office in the US” True, but proves nothing Circular argument: made up of several arguments where the conclusion of the last is a premise of the first

24. 24 III. 2) Complex Question Assumes a previous question has been answered “How long have you been cheating on tests?” Question by itself doesn’t constitute a fallacy; has to be part of an argument An implicit argument can often by found in a question (immigration example) Caveat: Not a complex question if embedded in a longer argument where the premises are explicitly stated

25. 25 III. 3) Suppressed Evidence When you know there is evidence contrary to your position, yet you suppress the evidence E.g. tobacco companies

26. 26 III. 4) False Dichotomy Occurs in the case of a disjunctive syllogism (either/or argument) Maria is either a Democrat or Republican Maria is not a Democrat So she is a Republican If disjunctive premise is false, the conclusion is false Example: 1950s motto, “Better dead than red”

27. 27 IV. Fallacies of Weak Induction Remember = inductive arguments are probable arguments Fallacy occurs when insufficient evidence is provided Weak induction fallacies occur when evidence cited is weak or incomplete evidence contrary to the conclusion is ignored

28. 28 IV. 1) Appeal to Authority Incorrect use of authority Assuming authority in one field implies authority in another Appeal to something as an authority (e.g. custom, popular opinion) when it is not

29. 29 IV. 2) Appeal to Ignorance A claim is made, either that since there isn’t any evidence that a proposition is false, it must be true, or that since there isn’t any evidence that the proposition is true, it must be false Nuclear power plant example Caveat: Some statements can look like an appeal to ignorance but aren’t

30. 30 IV. 3) Hasty Generalization When a conclusion is reached on the basis of insufficient evidence Can happen when a conclusion is drawn from an atypical sample or too small a sample

31. 31 IV. 4) False Cause Something is taken to be a cause when it isn’t (non causa pro causa, “not a cause as a cause”) Advertising tactic 1. One event follows another; first event is identified as the cause (post hoc ergo propter hoc, “before therefore because”) e.g. superstitions 2. Single cause identified but a complex situation Ronald Reagan ended the Cold War

32. 32 IV. 5) Slippery Slope Chain of causal claims with one or more of them false Often characterized by consequences getting progressively worse Cigarettes lead to heroin Caveat: There are valid causal chains Political issues like gun control - slippery slope or not?

33. 33 IV. 6) Weak Analogy An argument that uses analogy to persuade, but where there are ways in which the points of comparison are insufficient to support the claim or there are significant non-analogous points among the things compared