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DEFINITION: The arguer appeals to an inappropriate or unqualified authority (expert) as the basis for accepting a conclusion. The viewpoint of such an individual is logically irrelevant. However, an appeal to a legitimate expert (i.e., Einstein in physics; eye-witness in court case) is a type of inductive argument.

KEY DISTINCTION: This fallacy must be carefully distinguished from the legitimate or appropriate appeal to authority, which is a type of inductive (probabilistic) argument. The following criteria of credibility should be utilized when distinguishing between both versions:

1. Relevant, requisite expertise (field-specific competence)
2. Impartiality (not biased or prejudicial)
3. Truthfulness (no motive to lie)
4. Prerequisite ability to perceive or recall (witness in court proceeding)

1. Theistic physicist: Albert Einstein believed in the existence of God. Given Einstein’s incomparable intellectual stature in the scientific community, I must conclude that God actually does exist. And unless you, in your delusions of brilliance, think you’re smarter than Einstein, then you also must acknowledge God’s existence.

2. Commercial advertisement during Monday Night Football: The new Tumbleweed truck was judged best by the National Football League Rookie of the Year, defensive lineman Crusher "Psycho" Rockman. Now, you know that must be one tough truck. I wouldn’t buy any of those wimpy trucks driven by suburban, soccer moms!

3. Brown student Tom Roberts: I simply can’t agree with President Bush’s new economic stimulus package. Brown President Ruth Simpson has voiced her strong opposition to ‘Dubbya’s’ plan and that’s good enough to convince me.

4. Literary enthusiast: Aldous Huxley, the brilliant author of Brave New World, wrote a book advocating the view that nearsightedness can be corrected by eye exercises. Evidently, eyeglasses and contact lenses are quite unnecessary.

NOTE WELL: When determining whether an individual is a qualified authority, keep two points in mind:
1. Someone might be an authority in more than one field.
2. There are some areas in which practically no one can be considered an authority: politics, morals, and religion. Many questions in these areas are so hotly contested that there is no conventional wisdom an authority can convey. For example, one may be an expert in the history or philosophy of religion, but not an authority regarding the existence or nonexistence of God.


DEFINITION: The arguer claims that a thesis is true on the grounds that it has not been proved false. Or conversely, arguing that a thesis is false because it has not been proved true. However, both versions are appealing to very weak evidence, since the lack of a proof or demonstration of the truth of a thesis is not remotely sufficient evidence for its falsity. In turn, the absence of a proof of the falsity of a thesis does not constitute sufficient evidence for its truth. In other words, our ignorance (lack of proof or demonstration of either truth or falsity) is used as grounds or support for a definitive conclusion.

1. Fox Mulder, formerly of the X-Files: Despite numerous attempts, no one has proved to me that there is no government conspiracy to conceal the existence of extraterrestrial beings. The conclusion is inescapable; the conspiracy is taking place at this very moment

2. Atheist: For the third time Gabriel, I’ve read Augustine, Aquinas, Hegel, and almost all the major philosophers that argue for the existence of God. Yet, not one of them has proven that God actually does exist. Therefore, I am compelled to conclude that ‘god’ is an anthropomorphic concept constructed by human beings for their own comfort and consolation.

3. Concerned youth: Scientists have not conclusively shown that AIDS cannot be transmitted through casual contact. Consequently, we should carefully avoid any casual contact with suspected AIDS carriers.

4. Paranoid schizophrenic person: This Tom Brokaw guy begins every sentence with a word beginning with an ‘n,’ and we know my name, Normand, begins with an ‘n.’ He’s definitely talking to me in code, and don’t try to convince me otherwise unless you can prove he’s not talking to me in code.


A. Presumption of falsity with respect to unsupported statements of facts.
According to this principle, if expert researchers fail to confirm the truth or existence of an alleged phenomenon within their range of expertise then this failure constitutes positive evidence of the falsity or non-existence of the phenomenon in question.

Example: Mike Quinn, Boston architect: An international team of prestigious architects has been systematically searching for a way to make the CCRI Knight campus building more attractive or aesthetic. But after years of intense effort, no feasible means to this end have been discovered. Accordingly, students who take classes at the Knight campus will continue to hear the ominous, industrial drone as they walk up the ramp of the building. They may also be reminded of Pink Floyd’s song, Welcome to the Machine, as they do so.

B. Presumption of innocence in a court of law. 
According to this legal principle, the defendant is presumed innocent in the absence of evidence indicating guilt beyond a reasonable doubt.

Example: Defense attorney: Members of the jury, you have heard the prosecution present its case that my client did maliciously assault Barney the Dinosaur during a Warwick Mall promotion appearance. Nothing, however, has been proved beyond a reasonable doubt. Therefore, under the law, my client is not guilty.


DEFINITION: This fallacy is committed when the arguer draws a probable inference about all members of a class on the basis of an unrepresentative sample of that class. A selective sample may be unrepresentative of the entire class because of its limited quantity or because it does not accurately reflect the internal variety of the class in question (atypical sample). Therefore, Hasty generalization is a weak inductive argument, one that often serves to solidify prejudicial stereotypes. It is occasionally referred to as Converse accident because it proceeds in a direction opposite to that of Accident.

1. RISD student: I’ve seen several artistic performances at AS 220, including an industrial musical group named The Trendy Transvestites, a postmodern mime act, and a screening of the classic cult film Surf Nazis Must Die. They were all very intellectually and aesthetically stimulating. The conclusion is dear, artistic performances at AS 220 are excellent.

2. Howard Stern groupie: Did you know that 84 percent of males, ages 18-25, and living in Newport are avid Howard Stern listeners? They especially appreciate the clever way Mr. Stern reduces complex human problems to sensationalistic, graphic sexual jokes. Accordingly, Mrs. Wasp, a grandmother living in one of Newport’s lavish mansions, must be guffawing her guts out when Howard compares the pretentious snobbery of the upper class to the repulsive smell of excrement (actual term used by Mr. Stern not suitable for polite company).

3. Archie Bunker, character in the 1970s TV program All in the Family: What has the world come to? My son-in-law, Meathead the Pollock, is an unpatriotic, lazy, longhaired, idiotic idealist. You can cry political correctness all you want—you’re probably a pinko commie anyway—but the implication is obvious to anyone with old-fashioned common sense. Put simply, Pollocks are idiotic idealists.

4. Ms. Cutty Blade, founder of Women Fight Back:  Yes, I received my inspiration to start a radical women’s group some years ago while watching the Loranna Bobbitt trail on Court TV. I was most impressed by her method for resolving conflicts with men, which I’ve termed the ‘slice and dice’ conflict-resolution method. Henceforth, I’ve lectured extensively throughout the country, especially at private men’s clubs, that women everywhere should adopt this innovative method, thereby taking a stand against abusive males. Clearly, Ms. Bobbitt’s revolutionary example shows that this is the most effective way to resolve conflicts with men. Oh, by the way, RI Grinding currently is offering a discount on blade sharpening.


DEFINITION: This fallacy occurs whenever the link between premises and conclusion depends on some imagined causal connection that probably does not exist. The reality of the causal connection is presumed for some reason.


A. Post hoc: This version of the fallacy presupposes that just because one event precedes another event the first event must be the cause of the second event. Hence the Latin name: Post hoc ergo propter hoc ("after this, therefore on account of this"). Obviously, mere temporal succession is not a sufficient condition to establish a causal connection. Nevertheless, this kind of reasoning is quite common and lies behind most forms of superstition. (A precedes B; therefore A is the cause of B). Sequence alone is no proof of consequence.

1. Nervous entrepreneur:  Ever since we stopped going to church on Sunday, business has been progressively getting worse. If we want to avoid bankruptcy we better start going to church again.  

2. Devout child: Prayer works. Every time there is a storm I pray that our house will be spared, and not once have we been hit by lightning.

3. Real estate agent: Ms. Aquarius sold all three of her houses quickly because she placed the "For Sale" signs out at the exact time advised by her astrologer.

4. Superstitious supermodel: I couldn’t help myself, I watched the Victoria’s Secret prime time presentation on TV a few weeks ago. I was so angry one of the models had a better figure than mine that I secretly wished she were dead. Two days later I saw on Entertainment Tonight that she had been hospitalized with a severe case of the inhalation anthrax virus. According to ET, the authorities suspect she was exposed to the virus during her frequent visits to Sen. Daschle’s office. Now I feel really, really bad. How will I live with myself if she doesn’t survive? 

B. Non causa pro causa (Latin, not the cause for the cause): This version of False cause is committed when the arguer misidentifies the cause of something and the mistake is based on something other than mere temporal succession or sequence (Post hoc version). Hurley classifies two types of the Non causa fallacy.

B.1 Confusing Cause and Effect: This version is committed when one mistakes the cause for the effect, thereby reversing the actual causal connection.

1. 19th-century English social reformer: I have observed that every sober and industrious farmer owns at least one or two cows. Those who have none are usually drunken and lazy. Therefore, I recommend giving a cow to any farmer who has none, in order to make him sober and industrious.

2. Moralist critic of the Internet: I am outraged and indignant! It appears that, if you’re a famous or well-known woman, like Dr. Laura Schlesinger, nude photos of you end up somewhere on the Internet. Now everyone will be posting nude photos of himself or herself on the Internet so they can become a well-known celebrity. This recent cultural development is quite disturbing to say the least!

3. Hopeless dreamer: People who live in Beverly Hills are affluent, beautiful, and well known. So I’ve finally decided to leave my hometown of Newark, New Jersey and take up residence in Beverly Hills. In the near future look for me on the cover of the National Inquirer!

4. Charles Manson in prison, speaking to his cellmate: The governor sure seems to know when we’re having a good meal. He always conducts his annual inspection visit here at the Psychosis Correctional Center on the one day of the year that we have succulent sirloin steak! I reckon—I’ve been watching the movie Sling blade every day for a month—I’m not as crazy as people say, I figured out the governor is a psychic didn’t I?

B.2 Temporal Coincidence: In this type of the Non causa version of False cause the arguer claims a causal connection between two events or facts on the basis of their temporal coincidence or concurrence. But simply because two events happen to occur at approximately the same time is insufficient grounds for concluding that they are causally related.

1. Member of Congress: My dear colleagues, it is time to put an end to the importation of bananas. I have recently studied statistics covering the past forty years and I note with horror that the increase in the incidence of tuberculosis in our country runs almost exactly parallel to the increase in the volume of bananas imported here from Central America. We owe it to our constituents to ban once and for all the root cause of this terrible malady that afflicts so many of our countrymen.

2. Law enforcement official:  Studies reveal that the American people have become increasingly overweight during the past decade. During the same period statistics show a slight decrease in violent crime. Therefore, my proposal is that we should promote the consumption of mass quantities of ice cream in order to lower the violent crime rate even further.

3. Concerned parent:  More and more young people are attending colleges today than ever before. Yet there is more juvenile delinquency and more alienation among the youth of America. Clearly, their educators are corrupting these young people. Perhaps we should carefully consider the ancient Athenian solution to this “Socratic” problem.

4. Republican strategist: Under President Wilson we entered WW I, during President Roosevelt’s administration we became embroiled in WW II, with President Truman came the Korean War, and President Kennedy got us into the Vietnam War. Clearly, we should think twice before voting for a democrat in the 2000 election.

C. OVERSIMPLIFIED CAUSE: This variety of false cause is committed when a multitude of causes, often interrelated in some fashion, is responsible for a certain effect but the arguer (deliberately or due to ignorance) selects just one of these causes and represents it as if it were the sole, exclusive cause. The arguer is usually motivated by self-serving interests, such as taking undeserved credit for himself/herself, or giving such undeserved credit to a movement or organization with which he/she is affiliated. At other times, the arguer attempts to heap blame on an opponent or shift blame from himself/herself onto some convenient occurrence or condition.

1. Angry senior citizen: Look at our country today—kids killing kids, juvenile pregnancy, serial murderers, hate crimes, abuse of power at every turn, shallow materialism, obnoxious radio guys like Howard Stern, the President catching some "afternoon delight" with an intern, everyone’s a victim, and the violent sexism of rap music! How did we get into this tragic situation? The answer is simple. Somewhere along the way parents abandoned their responsibilities.

2. Educational theorist: Children spend an average of five hours a day watching television—time used to be spent reading. This obviously, increased television viewing is to blame for Scholastic Aptitude Test (SAT) scores dropping.

3. Children’s advocate: No wonder more children are joining gangs. When both parents work and spend so little time with their children, the children tend to look for some sort of family-like support.

4. Radio preacher: Marriage would be greatly helped if spouses would read the Bible and pray together every day. No wonder divorce has increased so much; family worship has dropped almost 90 percent in the last few years.


DEFINITION: Also called the Domino fallacy because of its similarity to the child’s game, the fallacy of Slippery slope is committed when the arguer draws a conclusion, typically considered to be inevitable, on the basis of an alleged chain reaction or series of causal steps with a seemingly innocent initial step that starts the process, just as in the game of dominoes or when one begins to slide down a slippery slope. As such, this fallacy is a variety of the False cause fallacy, yet we will consider it separately as Hurley does. The error of this fallacy consists in assuming, without sufficient evidence, that a particular event will start a causal chain reaction. However, for each event in any alleged series of events, an independent argument must be presented.

1. Anti-intellectual moralist: Studying philosophy is a very dangerous thing to do. It cultivates a critical attitude, which in turn makes an individual skeptical of their religious beliefs. And once you’ve begun to lose faith in your religion, it’s a small step to atheism. And we all know that atheism leads to immorality, which in turn leads to a life of crime. And lastly, a criminal lifestyle will get you damned to hell for eternity. Therefore, by all means, never study philosophy lest you also be damned to everlasting damnation!

2. Bioethicist: We must reject all attempts to make physician-assisted suicide legal. Once we turn down this road it’s inevitable that we’ll soon be practicing nonvoluntary euthanasia on inconvenient elderly citizens. And then what? We’ll be relieving anyone, regardless of age and ailment, we don’t like from their so-called suffering! Aren’t you glad ‘Dr. Death’ is behind bars?

3. Principal Pitius, voted most popular high school principal in a poll conducted by the teen magazine Trash Education: You’ve all heard of grade inflation. As a matter of fact, recently the Boston Globe reported that 91 percent of Harvard students graduate with honors. Well, I want to speak to you today about grade depression: the serious harm done to students by grading them too hard rather than too easily. What happens to students measured by an overly strict academic standard? They become frustrated and discouraged, which conditions them to expect failure. Consequently, they recoil from responsibility, always choosing the easiest route to anything rather than challenging and hence improving themselves. And on this basis they develop habits of dependency, eventually leading to symptoms of various psychological disorders. Can we really afford a generation of weak, dependent people ill suited for the many demands of contemporary society?

4. Charlton Heston, President of the National Rifle Association (NRA): If we allow the government to limit the number of guns a person can buy each month, what’s next? If they can limit gun purchases soon they’ll be telling us how much liquor or food we can buy, or even how many cars we can own. They already limit how many deer we can shoot. Next thing you know, Uncle Sam will be restricting the number of children we can have, like the Chinese communist government. Eventually, America will become like the government in George Orwell’s 1984 and control all aspects of our lives!


DEFINITION: The fallacy of Weak analogy is committed when a conclusion is based on an insufficient, poor, or inadequate analogy. The analogy offered as evidence is faulty because it is irrelevant; the claimed similarity is superficial or unrelated to the issue at stake in the argument. Or the analogy may be relevant to some extent yet overlooks or ignores significant dissimilarities between the analogs.

1. CCRI student: No one objects to the practice of a physician looking up a difficult case in medical books. Why, then, shouldn’t students taking a difficult exam be permitted to consult their textbooks?

2. Marquis de Sade: If one were to listen to only one kind of music or eat only one kind of food, it would soon become tasteless and boring. Variety makes eating and listening exciting and enriching experiences. Therefore, it cold be concluded that an exclusive sexual relationship with only one person for the rest of one’s life does not holdout much hope for very much excitement or enrichment.

3. Party animal:  Professor Iam A. Nerd teaches philosophy, drives a VW Jetta, has a cat, and is no fun at parties. Likewise Professor Leclerc teaches philosophy, drives a VW Jetta, and has a cat. Needless to say, I won’t be inviting Prof. Leclerc to my all-night graduation party next spring!

4. From David Hume’s On Suicide:  It would be no crime to divert the Nile or Danube from its course, were I able to effect such purposes. Where then is the crime of turning a few ounces of blood from their natural channel?