03 fallacies
- 1. Fallacies how not to argue logically Elements of Logic Spring 2013 «anti-copyright: do what you want with this
- 2. informal fallacies 1. fallacies of relevance These have in common the use of irrelevant information to try to persuade us into believing the conclusion. 2. fallacies of presumption These make additional unstated assumptions not warranted by the context. 3. fallacies of ambiguity These rest on the multiple meanings that often are attached to individual words and concepts.
- 3. appeal to ignorance Nobody has ever proved that God exists, therefore God does not exist.
- 4. appeal to ignorance There is no evidence of weapons of mass destruction in Iraq, thus there are really are no weapons of mass destruction in Iraq.
- 5. appeal to (illegitimate) authority Lance Armstrong says that we should all do our part to cut carbon emissions, so we should do so.
- 6. appeal to (illegitimate) authority Joe Camel says that smoking is good for you. Therefore, all of those stories about smoking being a health risk are wrong.
- 7. argument against the person abusive ad hominem Rush Limbaugh is a big fat liar! That is why you should not pay any attention to his arguments.
- 8. argument against the person circumstantial ad hominem Xandra is wearing a leather coat, calf-skin boots and a fur hat. So we can dismiss her arguments that animals should have rights.
- 9. argument against the person tu quoque: “You’re one too!” Rush Limbaugh and his current wife have six divorces between the two of them. So we can dismiss his arguments about why marriage should be forever.
- 10. appeal to emotion A world without God would be a cold and meaningless place, in which human lives have very little significance. Therefore religious belief must have some basis in reality.
- 11. appeal to pity I should not be held responsible for killing my wife. After all she was in bed with another man when I came home.
- 12. appeal to force Either I get a good grade in this class or you are a dead man, professor.
- 13. irrelevant appeal red herring I fail to see how helping out starving people in Africa is important. After all, there are plenty of hungry people right here at home.
- 14. irrelevant appeal straw person Those baby killing Democrats are proposing more health care legislation. We can safely say that it should be opposed.
- 15. irrelevant appeal non sequitur: “It does not follow.” The Patriots lost to the Ravens in the playoffs. Thus football is a really stupid sport.
- 16. fallacies of relevance 1. appeal to ignorance 2. appeal to illegitimate authority 3. argument against the person 4. appeal to emotion 5. appeal to pity 6. appeal to force 7. irrelevant appeal
- 17. complex question Have you stopped beating your kids?
- 18. complex question Do you love me?
- 19. false cause post hoc ergo propter hoc “after which therefore because of which” Yesterday I had a cold, so I drank a bottle of whiskey. Now I feel better. Thus whiskey cures colds.
- 20. begging the question You should be a Christian. If not, as the Bible suggests, you are going to end up in Hell.
- 21. accident stereotyping Bridget is a woman. Thus she should not serve in combat positions in the military.
- 22. accident genetic fallacy Biologists say we are descended from apes. But apes are dumb and we are smart, so those biologists must be wrong.
- 23. converse accident (hasty generalization) That person from Massachussetts is a terrible driver. So beware of all people with Massachussetts plates on their car.
- 24. suppressed evidence The shale gas boom is great for the economies of New York and Pennsylvania. After all there are lots of new jobs drilling for gas as a result.
- 25. false dichotomy (false dilemma) Either you are in favor of attacking Iran or you are un-unpatriotic. Since you are not in favor of an attack, you must be un-patriotic.
- 26. fallacies of presumption 1. complex question 2. false cause 3. begging the question 4. accident 5. converse accident (hasty generalization) 6. suppressed evidence 7. false dichotomy
- 27. equivocation Being free means being able to think whatever you want. People in jail can think whatever they want. Thus they are free and should quit complaining about how unfree they are.
- 28. amphiboly Last night I shot an elephant in my pajamas. How it got in my pajamas I’ll never know.
- 29. accent Obama: “We should stop giving away free health care to people who are unable to pay for it.” political opponent: “Obama is now talking about ‘giving away free health care to people who are unable to pay for it,’ and that is a direct quote.”
- 30. composition The military always follows orders. After all, everyone in the military follows orders.
- 31. division Neurons must be intelligent cells since the brain, which is the organ most responsible for intelligence, is made up of neurons.
- 32. fallacies of ambiguity 1. equivocation 2. amphiboly 3. accent 4. composition 5. division
- 33. fallacies 1. appeal to ignorance 2. appeal to illegitimate authority 3. argument against the person 4. appeal to emotion 5. appeal to pity 6. appeal to force 7. irrelevant appeal 8. complex question 9. false cause 10. begging the question 11. accident (stereotyping) 12. converse accident (hasty generalization) 13. suppressed evidence 14. false dichtomy 15. equivocation 16. amphiboly 17. accent 18. composition 19. division