Spotting faulty logic

1. Judging deceptive or faulty arguments in persuasive texts Spotting faulty logic

2. Do you believe everything you see?

3. Advertisements are designed to get you to buy things. Do you buy what you see on every ad? Newspaper and magazine editorials are written to get readers to share the author’s point of view. Do you agree with everything you read? Letters to the editor are citizen’s responses to what they’ve read in print media. Do you believe everything every stranger writes? Do you believe everything you read?

4. If you answered to no to each of the previous questions (and I hope you did!), why did you answer that way? If you think about people’s reasons for advertising and writing you’re off to a great start. However, if you begin to look at specific ways people to try to persuade you to buy, feel, think, or do certain things, you’ll be able to make more informed decisions. Do you believe everything you read?

5. They may earn money by getting you to buy something or pay for a service. They may gain power or influence by having you as a follower. Their cause may gain publicity the more followers they acquire. They may want you to believe as they do because they are convinced their belief is correct. They may want you to do something for them. Why might an author or speaker be dishonest?

6. Words to know • Anecdote • Analogy • Appeal • Deceit/ deceitful • Deceptive • Fallacy • Faulty • Logic • Premise • Specious

7. Deductive arguments are supposed to be water-tight. For a deductive argument to be a good one (to be “valid”) it must be absolutely impossible for both its premises to be true and its conclusion to be false. • Any deductive argument that fails to meet this (very high) standard commits a logical error, and so, technically, is a fallacy. • This includes many arguments that we would usually accept as good arguments, arguments that make their conclusions highly probable, but not certain. Arguments of this kind, arguments that aren’t deductively valid, are said to commit a “formal fallacy”. • The classic example of a deductively valid argument is: (1) All men are mortal.(2) Socrates is a man.Therefore:(3) Socrates is mortal. • It is simply not possible that both (1) and (2) are true and (3) is false, so this argument is deductively valid. Making a Logical argument

8. Types of faulty arguments • Ad hoc, ergo propter ad hoc • Ad hominem • Ad ignorantiam • Appeal to wrong authority • Card-stacking • Circular reasoning • Either/or fallacy • False analogy • False authority • Inconsistency • Personal incredulity • Straw man

9. Also called “false causation” This fallacy follows the basic format of: A preceded B, therefore A caused B, and therefore assumes cause and effect for two events just because they are temporally related (the Latin translates to "after this, therefore because of this"). Example: “My alarm goes off every morning at sunrise, therefore the sun rises because my alarm goes off.” Ad hoc, ergo ad propter hoc

10. Ad hominem attacks • An ad hominem argument is any that attempts to counter another’s claims or conclusions by attacking the person, rather than addressing the argument itself. Example: "Andrea Dworkin has written several books arguing that pornography harms women. But Dworkin is an ugly, bitter person, so you shouldn't listen to her." • Dworkin's appearance and character have nothing to do with the strength of her argument, so using them as evidence is fallacious. Ad hominem attacks are also known as “mud-slinging”.

11. An argument from ignorance (“ad ignoratiam” in Latin). The argument from ignorance basically states that a specific belief is true because we don’t know that it isn’t true. Example: "Of course telepathy and other psychic phenomena do not exist. Nobody has shown any proof that they are real." Ad ignorantiam

12. YouTube - Mike Huckabee Ad: "Chuck Norris Approved“ This ad also uses a testimonial wherein the fact that Chuck Norris is a celebrity is supposed to overrule the fact that he is not an authority on politics. Chuck Norris uses glittering generalities to discuss Huckabee’s qualifications to be president. Glittering generalities are words of praise for a product or person; using nice words like ‘goodness’ or ‘patriotism’. Appeal to wrong authority

13. Manipulating information to make a product appear better than it is often by unfair comparison or omitting facts. YouTube - New Mac Ad: Viruses This can also be considered an example of a straw man argument or selective evidence. card-stacking

14. Circular reasoning occurs when the reasoner begins with what he or she is trying to end up with. Example: A satisfied citizen says: “Richardson is the most successful mayor the town has ever had because he's the best mayor of our history.” The second part of this sentence offers no evidence — it simply repeats the claim that was already presented.  Don’t be fooled into believing that using the word “because” in an argument automatically provides a valid reason.  Be sure to provide clear evidence to support your claims, not a version of the premise (the initial statement in an argument). Circular reasoning

15. An either/or fallacy occurs when a speaker makes a claim (usually a premise in an otherwise valid deductive argument) that presents an artificial range of choices. Example: “Well, it is time for a decision. Will you contribute $10 to our environmental fund, or are you on the side of environmental destruction?” Either/ or fallacy

16. In an analogy, two objects (or events), A and B are shown to be similar. Then it is argued that since A has property P, so also B must have property P. An analogy fails when the two objects, A and B, are different in a way which affects whether they both have property P. Example: Students and nails are the same. As it is necessary to hit nails on the head in order to make them work, the same must be done with students. False analogy

17. Appealing to someone who is not an authority to give an expert opinion. You cannot use yourself as your own authority with total certainty, either.  Example: A doctor is more qualified to diagnose your shoulder pain than you are; your teachers are better qualified to evaluate your performance than a student. False Authority

18. The premise (proposition, or assumption) is not correct, the conclusion drawn may be in error. Example: If the streets are wet, it has rained recently. (premise) The streets are wet. (premise) Therefore it has rained recently. (conclusion) False premise

19. Applying criteria or rules to one belief, claim, argument, or position but not to others. The fallacy occurs when we accept an inconsistent set of claims, that is, when we accept a claim that logically conflicts with other claims we hold. Example: “I’m not racist. Some of my best friends are white. But I just don’t think that white women love their babies as much as our women do.” inconsistency

20. Arguing against a position which you create specifically to be easy to argue against, rather than the position actually held by those who oppose your point of view. Example: "Opposition to the North American Free Trade Agreement amounts to nothing but opposition to free trade." (Someone can believe in free and open trade and yet still oppose NAFTA.) Straw man

21. I cannot explain or understand this, therefore it cannot be true. Example: I don’t understand what the fossil record is or means, therefore dinosaurs must be made up. Personal incredulity

22. Types of Arguments that can be manipulated These types of arguments and evidence can be used, but you should be careful to use them sincerely and carefully

23. This kind of evidence involves telling stories of individuals suffering because of a problem related to the topic, or individual examples of incidents that support a claim. Examples: • Story of a woman murdered by a paroled killer in a state that doesn't have the death penalty. • Story of a teenage girl who died of a heroin overdose and who started using marijuana at age 12. • Story of someone who died of a treatable disease after waiting several months for a routine procedure in a country with nationalized health care. • Story of a college student in a country with a low drinking age who does not abuse alcohol. Anecdotal evidence

24. Intentionally failing to use information suspected of being relevant and significant is committing the fallacy of suppressed evidence. This usually occurs when the information counts against one’s own conclusion. Perhaps the arguer is not mentioning that experts have recently objected to one of his premises. The fallacy is a kind of fallacy of selective attention---improperly focusing attention on certain things and ignoring others. Appeals to Logic using Expert opinion

25. 73% of all statistics are made up. Insufficient Statistics--drawing a statistical conclusion from a set of data that is clearly too small. Example: A pollster interviews ten London voters in one building about which candidate for mayor they support, and upon finding that Churchill receives support from six of the ten, declares that Churchill has the majority support of London voters. Appeals to logic using Statistics

26. YouTube - Christine O'Donnell ad This ad also uses a “Plain Folks” appeal which appeals to regular people's values like family, patriotism, and their sense of distrust of the powerful and influential. Emotional appeal

27. It is your job as a careful read and a thoughtful writer to identify them when someone is working to persuade you and avoid using them when you are trying to persuade others. There are many more types of deceptive, illogical,and poorly constructed arguments