Discourse Fallacies Argument and Reasoning Categories of

Discourse Fallacies Argument and Reasoning

Categories of Fallacious Reasoning

Categories of Fallacious Reasoning

Fallacy of Subjectivism § “I believe (or want) x to be true, therefore x is true. ” § “Well, I was just brought up to believe that x. ” § “That may be true for you but it isn’t true for me. ”

Appeal to Majority § “A majority of people believe x, therefore x is true. ” § “I use correlation analysis as my statistical technique because it is one of the most popular methods among social scientists. ” § “Socialized medicine is good social policy because it is the wave of the future. ”

Appeal to Emotion § Not all emotional arguments are appeals to emotion. § A coherent argument can have profound emotive force. § The trouble comes when the pathos replaces the logos.

Appeal to Force (argumentum ad baculum) § Appeals to force can take the form of actual physical threats. § Usually they do not. § The appeal to force is committed whenever any kind of threat is used to secure agreement with a conclusion.

Appeal to Force (argumentum ad baculum) Examples: § Parents threaten to withdraw support of a child who won’t adopt their religious beliefs. § Teachers threaten dissenting students with lower grades. § “Persuasion” by threatening the loss of affection. § Holding dissenters up to ridicule. The appeal to force occurs whenever intimidation supplants logic.

Identify the Fallacy Is it subjectivism, appeal to majority, appeal to emotion, or appeal to force? The Golden Rule is a sound moral principle, for it is basic to every system of ethics in every culture. appeal to majority

Identify the Fallacy Is it subjectivism, appeal to majority, appeal to emotion, or appeal to force? Foreign imports are wrecking our economy and savaging our workers, the backbone of our country. Buy American! Before you put your money on that Honda, think of the guy in Detroit whose kids may not eat tomorrow. Before you buy those Italian pumps, ask yourself whether a little glamour is worth the job of the shoemaker in Boston who’s worked all his life to make an honest living. appeal to emotion

Identify the Fallacy Is it subjectivism, appeal to majority, appeal to emotion, or appeal to force? You can argue all you want to that democracy gives us only the illusion of control over the government, but I don’t buy it. I was brought up to believe in the democratic system. subjectivism

Identify the Fallacy Is it subjectivism, appeal to majority, appeal to emotion, or appeal to force? The most effective way to increase government revenues would be to raise the corporate income tax, since opinion polls show widespread support for such an approach. appeal to majority

Identify the Fallacy Is it subjectivism, appeal to majority, appeal to emotion, or appeal to force? Warning! Before answering the next question, please remember who assigns the grades in this course. appeal to force

Identify the Fallacy Is it subjectivism, appeal to majority, appeal to emotion, or appeal to force? “Fine. Go ahead and marry him. Why should you care about breaking your mother’s heart? I guess you love him more than me -- but why should I care? Who am I to complain? I’m only your mother. I only spent twenty years trying to make a good match for you, a nice boy, and now you run off. . ” appeal to emotion

Categories of Fallacious Reasoning

Appeal to Authority (Argumentum ad Verecundiam) § Rely on experts only if the conditions of credibility are satisfied. – The putative expert must be competent. – The putative expert must be “objective. ” – The subject matter must be too technical for the audience.

Ad Hominem § Attacking the speaker § and not her argument. § x says that p and x is bad therefore p is false. § Traits of the speaker relevant only when § assessing the competence of an expert. More sophisticated is the “tu quoque” variant. – Accusing the accuser of the accusation. “Poisoning the well” is another variant. – Attacking a position by claiming an

Identify the Fallacy Is it appeal to authority, or ad hominem (including tu quoque and poisoning the well)? I think America should be more careful about the international organizations we join and the treaties we sign. After all, wasn’t it George Washington himself who warned against “foreign entanglements”? appeal to authority

Identify the Fallacy Is it appeal to authority, or ad hominem (including tu quoque and poisoning the well)? Why should Congress consult the Joint Chiefs of Staff about military funding? They are military men, so obviously they will want as much money as they can get. Ad hominem -- poisoning the well

Identify the Fallacy Is it appeal to authority, or ad hominem (including tu quoque and poisoning the well)? A: “The poor nations of the world will have to learn to produce their own food if they are to solve the problem of hunger in the long run. ” B: “That’s a heartless position. You would never have said that if you had ever really been hungry. ” ad hominem

Identify the Fallacy Is it appeal to authority, or ad hominem (including tu quoque and poisoning the well)? This must be an important event. The New York Times gave it four columns on the front page. appeal to authority

Identify the Fallacy Is it appeal to authority, or ad hominem (including tu quoque and poisoning the well)? TV commentators are always attacking big business for making “obscene profits, ” but the companies they work for have higher profits than almost any other industry. ad hominem -- tu quoque

Categories of Fallacious Reasoning

Begging the Question (Circular Reasoning) Using an argument’s conclusion as one of its premises. Example: Society has an obligation to support the needy because people who cannot provide for themselves have a right to the resources of the community.

Begging the Question (Circular Reasoning) Using an argument’s conclusion as one of its premises. Example: a. Why do you believe God exists? b. Because the Bible says so. a. Why do you take the Bible’s word for it? b. Because God wrote it.

Begging the Question (Circular Reasoning) Using an argument’s conclusion as one of its premises. Complex Question: “Have you stopped beating your spouse? ” There are two questions here. The first is implicit: “have you been beating your spouse? ” An affirmative answer to this is presupposed in the explicit question.

Post Hoc, Ergo Propter Hoc (after this, thus because of this) A took place before B, therefore A caused B. . Example: “Marijuana use should remain illegal because most heroin addicts started off as marijuana users. ” Then let’s make milk drinking illegal too!

Post Hoc, Ergo Propter Hoc (after this, thus because of this) Spurious correlation Two variables correlate positively to the extent that their values rise and fall together. They correlate negatively to the extent that one rises whenever the other falls, and vice versa. Importantly, correlation is not causation!

Post Hoc, Ergo Propter Hoc (after this, thus because of this) Spurious correlation Ice Cream Sales Social Unrest

Post Hoc, Ergo Propter Hoc (after this, thus because of this) Spurious correlation Hot Weather Ice Cream Sales Social Unrest

False Alternative § Failure to consider all the possibilities. – “Joe is a liberal because he’s not a conservative. ” § Often found in a complex question: – “Do you favor reducing the deficit by increasing taxes or by reducing social spending? ” – Sometimes seen in public opinion research. – Absolutely nothing can be shown from data produced by such questions.

Appeal to Ignorance (Argumentum ad Ignorantiam) § “p hasn’t been proven false, so p is true. ” § The positive proposition generally starts the argument and bears the evidenciary burden of proof. § Legal principles apply rules to avoid appeals to ignorance. – The presumption of innocence in criminal law. – The presumption of non-liability in civil law.

Non Sequitur (“It Does Not Follow”) § Here, the premises are irrelevant to the conclusion. – Example: “Internet pornography is harmful. Therefore there ought to be a law against it. ” – What’s missing? § Support for the implicit contention that government intervention is appropriate in this case. – Why might it not be? § First amendment. § Global scope of internet.

Non Sequitur (“It Does Not Follow”) § Another form: § – Because an action had certain consequences, they were intended. § Another form is diversion or red herring. – Changing issues in middle of argument. The straw man argument. – Distorting opponent’s position. – Oversimplifying or caricaturing opponent’s argument. – Arguing against a position no one has taken.

Identify the Fallacy Which fallacy or fallacies of logical structure are committed? The federal government should save New York City from default, for New York deserves such aid. begging the question

Identify the Fallacy Which fallacy or fallacies of logical structure are committed? The layoffs at Acme Corporation were obviously racist: over 60 percent of the people laid off were Puerto Rican. non sequitur

Identify the Fallacy Which fallacy or fallacies of logical structure are committed? Hard-core pornography is disgusting and offensive to any civilized person, so it cannot be included in the right to free speech. non sequitur

Identify the Fallacy Which fallacy or fallacies of logical structure are committed? Six months after President Hoover took office in 1929, the stock market crashed and the Great Depression began. He is therefore responsible for this tragic episode in our national history. post hoc ergo propter hoc

Identify the Fallacy Which fallacy or fallacies of logical structure are committed? Why are you so skeptical about ESP? Can you prove that it doesn’t exist? appeal to ignorance

Identify the Fallacy Which fallacy or fallacies of logical structure are committed? Congressman Jones denies that he’s a liberal, so he must be a conservative. false alternative

Identify the Fallacy Which fallacy or fallacies of logical structure are committed? As a determinist, I believe that none of our actions results from free choice, and that all of them are determined by the strongest motive acting upon us. To be sure, it sometimes does seem that we choose to act on the weaker of two motives. But if we do that, it only shows that the motive which seemed weaker was really the stronger of the two, since it determined our action. begging the question

Identify the Fallacy Which fallacy or fallacies of logical structure are committed? Twenty-five years after graduation, Harvard alumni have average incomes much higher than the average college graduate. A Harvard education must be the road to riches. post hoc ergo propter hoc

Identify the Fallacy Which fallacy or fallacies of logical structure are committed? Opinion poll question: “Do you favor more money for welfare programs, or do you feel we should let people starve in the streets? ” false alternative

Identify the Fallacy Which fallacy or fallacies of logical structure are committed? Mary says she loves me. I don’t know whether to believe her or not, but I guess I do, because I don’t think she would lie to someone she loves about something that important. begging the question

The Naturalistic Fallacy § Deriving an evaluative conclusion from descriptive premises. – Inferring “ought” from “is. ” – Should be at least one evaluative premise if conclusion is evaluative. – Example: “We should teach multiplication by rote because we have always done so. ” § Searle’s naturalistic fallacy. § Duffy’s naturalistic fallacy.

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