PHILOSOPHY 4 FINAL REVIEW
"The Second Amendment to the Constitution guarantees everyone the right to bear arms. Therefore it should be legal for those undercover Al Qaeda members to buy a carload of shoulder-launched surface-to-air missiles."
Accident
Name the type of argument. "I'm painting our rooms green. When you go out into a field your eyes feel relaxed; that shows your eyes will feel relaxed in a green room, too."
Analogy
Name the type of argument. "I'm scared to let Susan see me in this sweater. A couple of my other friends told me it makes me look like a child, and she's at least as critical as they are."
Analogy
Name the type of argument. "Sparrows have little heads and they're not very smart. Dolphins and elephants have big heads, and so do people, and they're smart. So pigeons must be smarter than sparrows."
Analogy
"Sugar is sweet. Therefore, its chemical components, carbon, hydrogen, and oxygen, are sweet."
Division
A valid argument must have a true conclusion.
FALSE
If an argument is valid, then it must have a true conclusion.
FALSE
The concept of validity applies to propositions, and the concept of truth applies to arguments.
FALSE
"The engraved plate beneath this painting in the art museum says "Monet." Therefore, the painting must be the work of Monet."
Inductive, strong.
Which of the following best identifies the term "hence."
It is a conclusion indicator.
Which of the following best describes the term "since."
It is a premise indicator.
"Richard has been doing very poorly in biology this term. Therefore, he should schedule an appointment with the professor so he can criticize and berate her teaching ability."
Missing the point
"Most of the residents of the City Heights neighborhood are illiterate. Therefore, it would be a good idea to close the City Heights library. After all, nobody uses it."
Missing the point.
"After hearing Jordan's speech in the student council, Michael rolled his eyes and shook his head. Apparently Michael didn't agree with what Jordan said."
Neither
"Different kinds of organisms play different roles in the functioning of ecosystems. Plants and animals fix the energy of sunlight. Animals and protozoa consume biological forms of energy. Fungi break down biological materials and regenerate nutrients in the ecosystem."
Nonargument
"Senator Dawson argues in favor of legalizing gay marriage. But did you know that the senator has been married three times? And his last divorce was a real doozie. His wife went on and on about their sex life. Apparently the Senator is no good in bed. Enough about that issue ... . Shall we move on?"
Red herring
"Pet owners argue for a law to ensure that pet food is free of lethal contaminants. Apparently they are unaware that half the children of the world eat contaminated food and drink polluted water every day. Thousands of these kids die regularly from cholera. The nations of the world should unite to halt this ongoing tragedy. In the mean time, we can forget about pets."
Red herring.
A sound argument must have true premises.
True
An analogical argument is:
an inductive argument that uses the properties of a group to establish the existence or distribution of a property of another thing that resembles the members of that group.
"For the past four years, Clifford has gone on the Fourth of July hundred-mile bicycle ride sponsored by the Cyclamates, a local bicycle club. He has always become too exhausted to finish the entire hundred miles. He reaches the conclusion that he will not be able to finish the whole ride this year and decides to do only the last fifty miles." Assume that the target of an analogy is whatever one draws a conclusion about. The property (or feature in question) is whatever is attributed to the target in the conclusion of the analogy. In the case above, suppose 100% of the items in the sample have the property in question. What is the property in question?
being too exhausted to finish
An argument is a collection of claims intended to establish
the truth of a definite proposition.
Identify the type of inductive argument. "A watch could not assemble itself, because it's too complex. The universe is at least as complex as a watch. So the universe could not have assembled itself either."
Analogy
Identify the type of inductive argument. "Baseball is drama. You see new people each time in a new conflict; you never know what they'll do or how it will turn out; there's suspense."
Analogy
Identify the type of inductive argument. "You have to speak Sanskrit before you can say you know it. Would you believe someone who claimed to know Spanish or Russian and never spoke it? Sanskrit is a language just as they are."
Analogy
Name the type of argument. "Since the mid-1960s, most nominations to the Supreme Court have been clearly ideological, and the Senate approved or rejected them on ideological grounds. The President has to make a new nomination now, so we're probably in for a fight."
Analogy
"Members of the jury, surely you will not find defendant Carlos guilty of burglary. Carlos is a visitor from our neighbor to the south, where he has eight young brothers and sisters. Those poor kids and their impoverished mother live a desperate hand-to-mouth existence. Carlos was hoping only to send a few more dollars home to ease their suffering. In the name of humanity, you must vote to acquit this caring brother."
Appeal to pity.
"Can you believe that some parents want to control their kids' access to the Internet? Who are these autocrats who insist on imposing their views on others? This country was born in a spirit of freedom and self determination. Countless patriots have died to preserve our sacred values. We must cherish those values! We must nurture them in our children! End all mind control now and forever!"
Appeal to the people.
"Practically everyone has driven home at one time or other after having had a few drinks. Therefore, you shouldn't have any problem with driving home now, even though you're a bit tipsy."
Appeal to the people.
"The time has come to outlaw the use of tobacco in all public places. The noxious vapors from burning cigarettes and the stench of smoldering cigars is revolting to say the least. And that nasty brown slime squirting forth from the foul mouths of chewers is enough to turn one's stomach. End this assault on our health and senses this very instant! Send the filthy tobacco hounds back to where they came from!"
Appeal to the people.
"Irene will certainly live to a ripe old age because a palm reader told her that earlier today."
Appeal to unqualified authority.
"Philosopher Peter Singer argues for the right to kill handicapped newborn babies. But Singer is a disgusting irreligious crypto Nazi who is sometimes described as the most dangerous man in the world today. Obviously his arguments are nonsense."
Argument against the person, abusive.
"Floyd Conway has given us his reasons for unrestricted logging in our national forests. But it's obvious why he says these things. Floyd is a lumberjack, and he just wants to ensure that he'll have a job in the years ahead."
Argument against the person, circumstantial.
"Sarah argues that all of us should support the school bond issue on the September ballot. But it's obvious why she argues this way. She has six kids currently attending public school. Clearly her argument is worthless."
Argument against the person, circumstantial.
"Apple seeds and cherry pits are poisonous because they contain cyanide compounds. Your body can detoxify small quantities of these compounds, but larger doses can lead to difficulty in breathing, increased blood pressure and heart rate, and kidney failure. Reactions can include coma, convulsions, and death from respiratory arrest."
Argument; conclusion: Apple seeds and cherry pits are poisonous.
"Mass extinctions shape the overall pattern of macroevolution. The history of life on this earth includes many episodes of mass extinction in which many groups of organisms were wiped off the face of the planet. Mass extinctions are followed by periods of radiation where new species evolve to fill the empty niches left behind. It is probable that surviving a mass extinction is largely a function of luck. Thus, contingency plays a large roll in patterns of macroevolution."
Argument; conclusion: Contingency plays a large roll in patterns of macroevolution.
"Finding an identity as a Latino is a tricky issue in the United States because the pressure to assimilate is being repressed by the pressure to retain your roots. If you are deemed too assimilated into American culture, you are branded a "gringo" by your peers or even a turncoat to your blood and country. If you shun all American culture, you are branded as a freeloading malcontent who would be better off going back to where he came from. It is a lose-lose situation"
Argument; conclusion: Finding an identity ... in the United States.
"If you go to foreign films, if you go to documentaries, if you go to independent films, if you go to good films, you will become a better person because you will understand human nature better. Movies record human nature in a better way than any other art form. That's for sure."
Argument; conclusion: If you go to foreign films ... you will become a better person.
"Illegal immigrants pay local sales taxes, and many of them also pay state, local, and federal income tax and Social Security tax. They also purchase items from local merchants, increasing the amount these merchants pay in taxes. In addition, they work for low salaries, which increases the earnings of their employers and the amount of taxes these employers pay. Thus, it is not correct to say that illegal immigrants contribute nothing to the communities in which they live."
Argument; conclusion: It is not correct to say ... the communities in which they live.
"Prior to their extinction, Neanderthals had been widespread in Europe for 100,000 years. Then 50,000 years ago, modern humans moved into Europe from Africa. Twenty-six thousand years after that the last Neanderthal died. At one time it was thought that the Neanderthals were killed by climate change, but this theory has now been discounted. So why did the Neanderthals perish? Probably they were killed by the humans."
Argument; conclusion: Probably they were killed by the humans.
"Some over-the-counter medicines should not be given to very young children. For example, cold medicines contain decongestants and antihistamines. These substances raise blood pressure and heart rate. If an overdose should occur in a young child, the result can be fatal."
Argument; conclusion: Some over-the-counter medicines ... very young children.
"In general, whoever produces or distributes child pornography is subject to prosecution. But that rule is not absolute. For example, in 2002 the Supreme Court ruled that computer generated child porn is protected under the First Amendment. The Court reasoned that such pornography was permissible because no real children are exploited."
Argument; conclusion: That rule is not absolute.
"One need only point to the numbers. In the past 5 years, the cost of groceries such as bread, eggs, lettuce, and tomatoes has risen 5 percent per year. The cost of electricity has risen 4 percent, and natural gas has risen 8 percent. The cost of health care has gone up 5 percent per year. Hence, the cost of inflation to the average consumer is higher than the 2 to 3 percent touted by the government."
Argument; conclusion: The cost of inflation ... touted by the government.
"A report by the United Nations Food and Agriculture Organization states that intense livestock production causes more greenhouse gas emissions than driving cars. It is clear that increased rates of meat production and consumption are not sustainable. Thus, the easiest way to get a "greener conscience" and help the Earth is to adopt a vegetarian diet."
Argument; conclusion: The easiest way ... adopt a vegetarian diet.
"The loss of arctic ice is accelerating as a result of a form of positive feedback. As arctic ice melts, the arctic icecap reflects fewer rays from the sun. When this happens, more rays are absorbed by the surrounding ocean, which increases its temperature. As the temperature of the ocean rises, more arctic ice melts."
Argument; conclusion: The loss of arctic ice ... positive feedback.
"Good intentions aside, there are compelling reasons to avoid water fluoridation. Hydrofluosilic acid, the industrial waste product used in municipal water systems, is contaminated with arsenic, lead, and other heavy metals. There are significant increases in lead levels in children who drink fluoridated water. A 2006 Harvard study found a fivefold to sevenfold increase in bone cancer in exposed young men. Sadly, the youngest children are the most susceptible."
Argument; conclusion: There are compelling reasons to avoid water fluoridation.
"To focus on the performance of the stock market is to zero in on an economic indicator that can do well even as the country does poorly. In 2006, for instance, the Dow Jones industrial average hit highs. According to the just released census data, however, median earnings fell one percent, and millions more Americans entered the ranks of the uninsured. Indeed, from 2000 to 2007 the S&P 500 gained more than 500 points. Meanwhile, the median household income fell by more than $900."
Argument; conclusion: To focus on the performance ... even as the country does poorly.
"Scientists have recently shown that heaps of intact DNA from the extinct wooly mammoth are retrievable from the animals' fur. A great deal of that fur is readily available in natural history museums. Such amounts of DNA make it possible to piece together the entire mammoth genome. Hence, we can expect to see mammoth clones in the not too distant future."
Argument; conclusion: We can expect to see ... in the not too distant future.
"The Bible is unquestionably true because deep in my heart I feel that it is."
Begging the question.
"Every student that members of our team met from Holy Toledo State believes in God. My conclusion is that most of the students from Holy Toledo State believe in God." Assume that the target of an analogy is whatever one draws a conclusion about. The property (or feature in question) is whatever is attributed to the target in the conclusion of the analogy. In the case above, what is the property in question?
Belief in God
Every student that members of our team met from Holy Toledo State believes in God. My conclusion is that most of the students from Holy Toledo State believe in God." Assume that the target of an analogy is whatever one draws a conclusion about. The property (or feature in question) is whatever is attributed to the target in the conclusion of the analogy. In the case above, what is the property in question?
Belief in God
Which of the following claims is most accurate?
Biased generalizations are unjustified because they are unrepresentative.
Consider this argument: "It make sense that capital punishment deters people from committing crime. If someone is about to commit a crime and they realize that they could be put to death for it, then they will probably think twice about doing it. And if people think twice about committing crimes, then they are more likely to refrain from committing them. And if people refrain from committing crimes, then they are being deterred from committing crime." Which of the following is the conclusion?
Capital punishment deters people from committing crime.
"For the past four years, Clifford has gone on the Fourth of July hundred-mile bicycle ride sponsored by the Cyclamates, a local bicycle club. He has always become too exhausted to finish the entire hundred miles. He reaches the conclusion that he will not be able to finish the whole ride this year and decides to do only the last fifty miles." Assume that the target of an analogy is whatever one draws a conclusion about. The property (or feature in question) is whatever is attributed to the target in the conclusion of the analogy. Identify the target of Clifford's argument.
Clifford's next ride on July 4 with the Cyclamates
Identify the sample mentioned in Clifford's argument. "For the past four years, Clifford has gone on the Fourth of July hundred-mile bicycle ride sponsored by the Cyclamates, a local bicycle club. He has always become too exhausted to finish the entire hundred miles. He reaches the conclusion that he will not be able to finish the whole ride this year and decides to do only the last fifty miles."
Clifford's previous four attempts
"An instant has no duration. But an hour is composed of instants. Therefore, an hour has no duration."
Composition
"An instant has no duration. But an hour is composed of instants. Therefore, an hour has no duration."
Composition.
"Enzo likes to eat. He also likes to drive. It follows that Enzo likes to eat while he's driving."
Composition.
In the Sunrise University History Department, students are invited to submit written evaluations of their instructors to the department's personnel committee, which uses those evaluations to help determine whether history instructors should be recommended for retention and promotion. In his three history classes, Professor Ludlum has a total of one hundred students. Sixteen students turned in written evaluations of Professor Ludlum; fourteen of these evaluations were negative, and two were positive. Professor Hitchcock, who sits on the History Department Personnel Committee, argued against recommending Ludlum for promotion. "If a majority of the students who bothered to evaluate Ludlum find him lacking," he stated, "then it's clear to me that a majority of all his students find him lacking." Assume that the target of an analogy is whatever one draws a conclusion about. The property (or feature in question) is whatever is attributed to the target in the conclusion of the analogy. What is the target in the argument above?
Correcte. students in Prof. Ludlum's history classes
"If pigs can fly, then Ugly Betty will win a beauty contest. Pigs cannot fly. Therefore, Ugly Betty will not win a beauty contest."
Deductive
"No taggers are good citizens,because all taggers are criminals, and no criminals are good citizens."
Deductive
"Andrew is lighter than Carl, and Carl is heavier than Marty. Therefore, it follows that Andrew is lighter than Marty."
Deductive, invalid.
"If X is a cat, then X is a mammal. And, if X is a cat, then X is a carnivore. Thus, if X is a mammal, then X is a carnivore."
Deductive, invalid.
"If pigs can fly, then Ugly Betty will win a beauty contest. Pigs cannot fly. Therefore, Ugly Betty will not win a beauty contest."
Deductive, invalid.
"Louis graduated from college after Cheri, and Cheri graduated before Denise. Therefore, it follows necessarily that Louis graduated before Denise."
Deductive, invalid.
"Lydia loves Ryan, and Ryan loves anchovy pizza. Therefore, Lydia loves anchovy pizza."
Deductive, invalid.
"No taggers are good citizens, because all taggers are criminals, and no criminals are good citizens."
Deductive, invalid.
"Some preachers are evangelists, so some preachers are TV personalities, since some evangelists are TV personalities."
Deductive, invalid.
"All aerobic exercises are calorie burners and all calorie burners are weight reducers. Thus, all aerobic exercises are weight reducers."
Deductive, valid.
"Brandon is an atheist. All atheists believe that there are no gods. Therefore, Brandon believes that there are no gods."
Deductive, valid.
"Either Bill Clinton or George W. Bush was president when the World Trade Center towers were destroyed. But Bush was not president at that time. Therefore, Bill Clinton was president when those buildings were destroyed."
Deductive, valid.
"Either Leonardo da Vinci or Andrew Wyeth painted the Mona Lisa. But it clearly was not da Vinci. Therefore, Andrew Wyeth painted the Mona Lisa."
Deductive, valid.
"Natalie is a kleptomaniac. Kleptomaniacs have a compulsion to steal things. Therefore, she has a compulsion to steal things."
Deductive, valid.
Human societies rapidly descend into anarchy and chaos without policing. Now, researchers have found that the same thing happens when groups of monkeys are left to their own devices instead of being "policed" by dominant males. It was already well known that in groups of pigtailed macaques (Macaca nemestrina), dominant males keep the rest in order through a form of policing. As they patrol the herd, they frequently receive peaceful "bared teeth" signals from other, subordinate monkeys, acknowledging that the dominant male is in charge. The "police" macaques often intervene to defuse scuffles before they can escalate. To find out what happens when the primate police are missing, Jessica Flack of the Santa Fe Institute in New Mexico, US, and her colleagues temporarily removed three of four dominant males simultaneously from a captive group of 84 pigtailed macaques at the Yerkes National Primate Research Center, near Lawrenceville, Georgia, US. Disproportionate power While they were gone, group cohesion rapidly began to disintegrate. The researchers saw cliques forming and the breakdown of social networks and contact through communal activities like playing, grooming and sitting together. The amount of violence also escalated, with no one to broker the peace. "In our macaques, a few individuals were perceived as disproportionately powerful. These animals are recognised as being very capable of using force successfully," says Flack. "One of the important implications is this feedback between power structure and social network structure". Another member of the research team, Frans de Waal at the Yerkes Primate Research Center, Emory University, Georgia, notes: "We tend to associate power with privilege, but both in human and animal society it also entails a constructive contribution, or at least ought to. Through their stabilising presence and active peacekeeping, the dominant males contribute to a more cooperative society." Journal reference: Nature (vol 439, p 426)
Dominant males contribute to a more cooperative society.
"Dan tosses a coin 10 times and each time it lands heads up. Marie says the odds are very high that the coin will land tails up on the 11th toss. Dan reasons that the coin is fair and has no memory. Therefore, he disagrees with Marie." Which of the following is the best formulation of the reasoning used by Dan?
Events one through eleven are independent of each other, so the coin doesn't know that the sequence is low on tails, so Marie shouldn't predict it will probably come up tails next time.
An inductively strong argument must be deductively valid.
False
"Shortly after retiring from his job, Mr. Lopez had a heart attack and died. The same thing happened to Mrs. Harris. I think the message is clear: Whatever you do, never retire from your job."
False cause
"Whatever you do, never accept a date from Ken Bradshaw. The last woman to date Ken broke up with him in just 3 weeks and became a lesbian."
False cause
"A few days after Margi joined the Democratic Party she broke her foot and lost her job. Therefore, it's important that you never join up with the Democrats."
False cause.
Identify the type of inductive argument. "We approached women in malls, college campuses, office buildings, and airports, until we had interviewed a thousand. Sixty-two percent told us they don't feel disadvantaged by being women. Even accounting for the error margin, that gives a clear majority who feel this way."
Generalization
Connie is thinking about registering for Professor Langley's course in Italian Renaissance history. Connie's friend Lydia took that course a year earlier and got an A. Connie figures that she will get an A, too. How does the following fact bear on Connie's conclusion? Connie and Lydia both use Apple computers.
Has no effect.
"Carol has a rottweiler dog, and it attacked and seriously injured one of his neighbors. David has a rottweiler and it chewed up his wife. The conclusion is obvious: rottweilers are vicious."
Hasty generalization
"James Watson, co-discoverer of the structure of the DNA molecule, says that Charles Darwin is the most important biologist to have ever lived. Therefore, it must be the case that Charles Darwin is the most important biologist to have ever lived."
Inductive
"The pop-up message on your computer screen says "Earn $10,000 per week. Call 306-981-4872." Therefore, if you call that number you can earn $10,000 per week."
Inductive
"After Scott started the engine in his old Chevy, the car backfired several times, and clouds of smoke came from the exhaust pipe. Apparently something must be wrong with the engine."
Inductive, strong.
"After drinking a bottle of Black Diamond Special Brew, Clyde noticed a slightly bitter aftertaste. Lauren and Nicole noticed the same thing when they drank some Black Diamond a year earlier. We conclude that every bottle of Black Diamond Special Brew has a slightly bitter aftertaste."
Inductive, strong.
"As global warming continues, the temperature of the world's oceans will rise. As ocean temperatures rise, hurricanes will become more intense. Therefore, hurricanes in the Caribbean will intensify in the years ahead."
Inductive, strong.
"As the universe expands, it gets colder and colder. Furthermore, this expansion will continue for ever and ever. Therefore, at some point in the future the universe will become too cold to support human life, and all humans will perish."
Inductive, strong.
"James Bloomfield, the widely respected expert on art authentication, says that the painting recently discovered in the basement of the art museum is a genuine Picasso. Therefore, we conclude that the painting is indeed a genuine Picasso."
Inductive, strong.
"The arctic ice cap has been shrinking for several years as a result of global warming, and that trend is expected to continue. Therefore, since arctic polar bears depend on that ice for survival, the arctic polar bear population will shrink in the years ahead."
Inductive, strong.
"To the lower right of the image of Thomas Jefferson on this U.S. five-cent coin we see '1975.' It must be the case that the coin was minted in 1975."
Inductive, strong.
"Graffiti painted on that vacant building says 'Boycott Meat.' Therefore, we should all become vegetarians."
Inductive, weak
"A divining rod is a magical device for detecting hidden water, metal, and gemstones. Your friend Roger is using his divining rod on the beach right now. Therefore, he'll probably find some diamonds buried beneath the sand."
Inductive, weak.
"After Sally stopped wearing Levi jeans, she started having vision problems. Therefore, to clear up her vision problems, Sally should go back to wearing her Levi jeans."
Inductive, weak.
"After buying a pair of Blue Atlas jeans, Carter was disappointed to find that they fell apart after only one month. The same thing happened to Jeff, Mario, and Ralph. Apparently Blue Atlas jeans don't hold up very well."
Inductive, weak.
"After investing in the stock market, Pamela doubled her money in just two years, and Beth and Tiffany did the same thing. However, Greg, Ivan, and Marty all lost money on the stock market during the same time frame. The obvious conclusion is that women do better than men in the stock market."
Inductive, weak.
"Astrological calculations indicate that the U.S. stock market will crash in the year 2019. Therefore, you should get your money out of the market before that year."
Inductive, weak.
"During the past 80 years, the number of Model T Fords on the highway has steadily fallen while the number of deaths from lung cancer has steadily risen. Thus, to reduce the number of deaths from lung cancer we should bring back the Model T Ford."
Inductive, weak.
"Graffiti painted on that vacant building says 'Boycott Meat.' Therefore, we should all become vegetarians."
Inductive, weak.
"Henry and Carl, who are neighbors, are about the same age, and they both have heart conditions. Henry takes Digitoxin for his heart, and it relieves his symptoms. Therefore, it would be a good idea for Carl to take the same medicine for his heart."
Inductive, weak.
"James Watson, co-discoverer of the structure of the DNA molecule, says that Charles Darwin is the most important person to have ever lived. Therefore, it must be the case that Charles Darwin is indeed the most important person to have ever lived."
Inductive, weak.
"When Jack took his car in for service, the mechanic charged him for lots of work that didn't need to be done. The same thing happened to Niki and Claire. Mechanics these days are just a bunch of crooks."
Inductive, weak.
"When asked how to address the militaristic ambitions of Syria, two Republican senators said we should drop bombs on Damascus, and a third said we should invade. The obvious conclusion is that Republicans are all a bunch of war mongers."
Inductive, weak.
"Every hair on Jane's head is naturally blond. Therefore, Jane is a natural blond."
No fallacy
"Movie star Marci Downs says in magazine ads that the new Porsche XKG is the sexiest car on the road. But you shouldn't take what she says too seriously because she's paid thousands of dollars to make these ads."
No fallacy
"Rachel could not possibly have painted this beautiful landscape scene. Rachel is so inept she doesn't even know which end of the brush goes in the paint. And she hasn't a shred of ability when it comes to color or design."
No fallacy
Every squirrel that has ever been observed likes nuts. Therefore, probably every squirrel likes nuts."
No fallacy
"Either Thomas Edison or Samuel F. B. Morse invented the telegraph. But it wasn't Edison. Therefore, Morse invented the telegraph."
No fallacy.
"Every ingredient in this new drink concoction is highly alcoholic. Therefore, the drink is highly alcoholic."
No fallacy.
"Rachel could not possibly have painted this beautiful landscape scene. Rachel is so inept she doesn't even know which end of the brush goes in the paint. And she hasn't a shred of ability when it comes to color or design."
No fallacy.
"The Ionic Blast hairdryer does a great job removing the frizz from Francesca's hair. Therefore, since Gabriella's hair is virtually identical to Francesca's, probably the Ionic Blast would do a good job removing the frizz from Gabriella's hair."
No fallacy.
In the Sunrise University History Department, students are invited to submit written evaluations of their instructors to the department's personnel committee, which uses those evaluations to help determine whether history instructors should be recommended for retention and promotion. In his three history classes, Professor Ludlum has a total of one hundred students. Sixteen students turned in written evaluations of Professor Ludlum; fourteen of these evaluations were negative, and two were positive. Professor Hitchcock, who sits on the History Department Personnel Committee, argued against recommending Ludlum for promotion. "If a majority of the students who bothered to evaluate Ludlum find him lacking," he stated, "then it's clear to me that a majority of all his students find him lacking." Is the size of the sample large enough to help ensure that the sample and target classes won't be too dissimilar?
No, because these data do not support that inductive conclusion.
"Evolution as a process that has always gone on in the history of the earth can be doubted only by those who are ignorant of the evidence or are resistant to evidence, owing to emotional blocks or to plain bigotry. By contrast, the mechanisms that bring evolution about certainly need study and clarification. There are no alternatives to evolution as history that can withstand critical examination. Yet we are constantly learning new and important facts about evolutionary mechanisms."
Nonargument
"Geology can be divided into two major time-related disciplines: physical geology and historical geology. Physical geology is the study of the materials the planet is composed of and the present day processes that operate on the surface and within the earth's deeper layers. Historical geology is the study of the earth's 4.6 billion year history, its formation, development, and evolution. Historical geologists strive to create a time-line of events that have occurred since the earth's formation."
Nonargument
"Hair turns color when we age because the follicles at the base of the hair shaft cease to produce melanin. Melanin is a chemical that gives the hair shaft its color (black, brown, blond, red, and all shades in between). The darkness or lightness of your hair depends on how much melanin each strand contains. With age, the cells in the follicle that produce melanin die off. As they do so, that hair strand will become silver, grey, or white, as it grows."
Nonargument
"Harnessing the clean, abundant energy of the sun and wind is critical to solving the global warming problem. Technological advances have brought the cost of electricity generated by the wind down by 82 percent since 1981. Solar energy technology has made remarkable progress as new photovoltaic cells have been developed to convert even greater amounts of sunlight directly into electricity. Today the costs of wind and solar power are becoming competitive with dirty coal-fired plants."
Nonargument
"If its ion engine operates as planned, its huge solar panel remains deployed and undamaged, and its xenon energy source is not exhausted, then the Dawn spacecraft will reach both Vesta and Ceres (large asteroids in the belt between Mars and Jupiter), and scientists will gather information about the formation of planets, whether Ceres has a buried ocean of fresh water, and whether vestiges of life lurk beneath its icy surface."
Nonargument
"If people buy cars that are more efficient, replace large appliances with energy efficient ones, unplug unused freezers and refrigerators, replace incandescent light bulbs with compact fluorescent models, and plant trees on private property and public land, then millions of tons of heat-trapping gasses will be kept out of the atmosphere, the current level of these gasses will be reduced, and the catastrophic consequences of global warming will be averted."
Nonargument
"Karl Marx believed that the key to human history was class conflict. According to Marxist theory, the bourgeoisie are locked in inevitable conflict with the proletariat. This bitter struggle can end only when members of the working class unite in revolution and throw off their chains of bondage. The result will be a classless society, one free of exploitation, in which everyone will work according to their abilities and receive according to their needs."
Nonargument
"Life does not exist in a vacuum. Each organism interacts continuously with its environment. The roots of a tree, for example, absorb water and minerals from the soil. The leaves take in carbon dioxide from the air. Solar energy absorbed by chlorophyll drives photosynthesis, which converts water and carbon dioxide to sugar and oxygen. The tree releases oxygen to the air, and its roots help form soil by breaking up rocks."
Nonargument
"Little is known of the Greek physician Hippocrates, who lived around 400 B.C. Nevertheless, the writings attributed to him have provided a number of principles underlying modern medical practice. One of his most famous contributions, the Hippocratic Oath, is the foundation of contemporary medical ethics. It requires the physician to swear that he or she will help the sick, refrain from intentional wrongdoing, and keep confidential all matters pertaining to the doctor-patient relationship."
Nonargument
"Numerous studies have indicated that women of color, black women in particular, are, over-arrested, over-indicted, and over-sentenced. African-American women are seven times more likely to be arrested for prostitution than women of other ethnic groups. Black women have received significantly longer sentences for crimes against property and served longer periods in prison. For both murder and drug offenses, Euroamerican women ended up serving one-third less time for the same offenses than black women."
Nonargument
"The earth is divided into the crust, the mantle, and the core. The crust is the solid portion on which we stand. The mantle is a plastic but solid material under the crust that can flow and move about. And finally, the core is the innermost part of the earth made of solid and molten iron."
Nonargument
"The parallel concepts of the element and the atom constitute the very foundations of chemical science. An element is a substance that cannot be broken down into a simpler form capable of an independent existence as observable matter. As such, the concept of the element is a macroscopic one that relates to the world that we can observe with our senses. The atom is the microscopic realization of this concept. That is, it is the actual physical particle that is unique to each chemical element."
Nonargument
"The relationship between two measurable factors can be represented by a graph. If both values increase, they are considered to have a direct relationship. For example, the more you work, the more money you make. If one value increases while the other decreases, they have an inverse relationship. For example, the more you work on your golf swing, the lower your score will be."
Nonargument
"The story of ever-increasing divorce is a powerful narrative, but it is also wrong. In fact, the divorce rate has been falling continuously over the past quarter-century, and is now at its lowest level since 1970. While marriage rates are also declining, those marriages that do occur are increasingly more stable. For instance, marriages that began in the 1990s were more likely to celebrate a 10th anniversary than those that started in the 1980s, which, in turn, were also more likely to last than marriages that began back in the 1970s."
Nonargument
"The theory of continental drift was reinforced when scientists discovered the remains of a reptilian fossil called Mesosaurus both in Brazil and South Africa, but nowhere else in the world. If these two continents were joined together at one time, it would explain why this reptilian fossil would be found only in those two countries. Since that discovery, the theory of continental drift has been expanded and has become known as the theory of plate tectonics."
Nonargument
Background: Herpes simplex virus type 2 (HSV-2) infection is usually transmitted sexually and can cause recurrent, painful genital ulcers. In neonates the infection is potentially lethal. We investigated the seroprevalence and correlates of HSV-2 infection in the United States and identified changes in HSV-2 seroprevalence since the late 1970s. Methods: Serum samples and questionnaire data were collected during the National Health and Nutrition Examination Surveys (NHANES) II (1976 to 1980) and III (1988 to 1994). HSV-2 antibody was assessed with an immunodot assay specific for glycoprotein gG-2 of HSV-2. Results: From 1988 to 1994, the seroprevalence of HSV-2 in persons 12 years of age or older in the United States was 21.9 percent (95 percent confidence interval, 20.2 to 23.6 percent), corresponding to 45 million infected people in the noninstitutionalized civilian population. The seroprevalence was higher among women (25.6 percent) than men (17.8 percent) and higher among blacks (45.9 percent) than whites (17.6 percent). Less than 10 percent of all those who were seropositive reported a history of genital herpes infection. In a multivariate model, the independent predictors of HSV-2 seropositivity were female sex, black race or Mexican-American ethnic background, older age, less education, poverty, cocaine use, and a greater lifetime number of sexual partners. As compared with the period from 1976 to 1980, the age-adjusted seroprevalence of HSV-2 rose 30 percent (95 percent confidence interval, 15.8 to 45.8 percent). The seroprevalence quintupled among white teenagers and doubled among whites in their twenties. Among blacks and older whites, the increases were smaller.
One in five persons 12 years of age or older are HSV-2 positive.
Which of the following is a weak or faulty generalization?
Samples of populations inadequately represent their target population.
"The use of marijuana for medical purposes should never be allowed. Before long it will be marijuana for anyone who wants it. Then it will be hash, cocaine, and crack. In no time they'll want crystal, ecstasy, and heroine. In the end everyone will be so drugged out they won't be able to see straight."
Slippery slope.
"Professor Harris gives a number of reasons why we should turn off our cell phones during class. It appears that Harris is one of those Luddites who are opposed to technology altogether. No laptops, no iPods, no digital cameras⎯that's what Harris wants. But that's just ridiculous. Thus, it's clear that Harris is wrong."
Straw man
"Karen argues that it's not right to post the photographs of convicted child molesters on the Internet. Obviously Karen supports child molestation. But these monsters have completely ruined the lives of thousands of children. They can't be allowed to wreak their havoc any longer. Clearly, Karen's argument is misguided."
Straw man.
Connie is thinking about registering for Professor Langley's course in Italian Renaissance history. Connie's friend Lydia took that course a year earlier and got an A. Connie figures that she will get an A, too. How does the following fact bear on Connie's conclusion? Both speak and read Italian.
Strengthens
Connie is thinking about registering for Professor Langley's course in Italian Renaissance history. Connie's friend Lydia took that course a year earlier and got an A. Connie figures that she will get an A, too. How does the following fact bear on Connie's conclusion? Connie discovers four biology majors who took professor Langley's course in Italian Renaissance history, and all four got As.
Strengthens
"Every student that members of our team met from Holy Toledo State believes in God. My conclusion is that most of the students from Holy Toledo State believe in God." Assume that the target of an analogy is whatever one draws a conclusion about. The property (or feature in question) is whatever is attributed to the target in the conclusion of the analogy. In the argument above, what is the target?
Students from Holy Toledo State
"Every student that members of our team met from Holy Toledo State believes in God. My conclusion is that most of the students from Holy Toledo State believe in God." Assume that the target of an analogy is whatever one draws a conclusion about. The property (or feature in question) is whatever is attributed to the target in the conclusion of the analogy. In the argument above, what is the target?
Students from Holy Toledo State.
"During the past 100 years the average minimum wage in the U.S. has been less than $2 per hour. Therefore, during the next 100 years the average minimum wage in the U.S. will be less than $2 per hour."
Suppressed evidence.
A valid argument may have a false conclusion.
TRUE
All invalid arguments are unsound.
TRUE
All sound arguments are valid.
TRUE
"They should not raise student tuition. A large part of the university's budget is currently being used inappropriately. The adminstrators gave themselves hefty raises, we're loosing full-time, tenured professors at an alarming rate, and buildings with no classrooms are being built." Which of the following is the conclusion?
They should not raise student tuition.
Consider this argument: "I don't believe that watching violent tv and movies causes people to be violent. I have watched lots of violent tv and movies, and I am not violent." Which of the following is the conclusion in the argument?
Watching violent tv and movies does not cause people to be violent.
"It's dangerous to use a hair dryer while taking a bath. But a rechargeable shaver is an electrical device no less than a hair dryer. Therefore, it's dangerous to use a rechargeable shaver while taking a bath."
Weak analogy.
Connie is thinking about registering for Professor Langley's course in Italian Renaissance history. Connie's friend Lydia took that course a year earlier and got an A. Connie figures that she will get an A, too. How does the following fact bear on Connie's conclusion? Lydia is a history major, but Connie is a biology major.
Weakens
In the Sunrise University History Department, students are invited to submit written evaluations of their instructors to the department's personnel committee, which uses those evaluations to help determine whether history instructors should be recommended for retention and promotion. In his three history classes, Professor Ludlum has a total of one hundred students. Sixteen students turned in written evaluations of Professor Ludlum; fourteen of these evaluations were negative, and two were positive. Professor Hitchcock, who sits on the History Department Personnel Committee, argued against recommending Ludlum for promotion. "If a majority of the students who bothered to evaluate Ludlum find him lacking," he stated, "then it's clear to me that a majority of all his students find him lacking." Assume that the target of an analogy is whatever one draws a conclusion about. The property (or feature in question) is whatever is attributed to the target in the conclusion of the analogy. What is the target in the argument above?
students in Prof. Ludlum's history classes
Consider: "Every student that members of our team met from Holy Toledo State believes in God. My conclusion is that most of the students from Holy Toledo State believe in God." Holy Toledo State is a university and has no admission requirements pertaining to religious beliefs. Suppose that all of the students interviewed were on Holy Toledo State's women's volleyball team. How does this supposition affect the strength of the argument?
weakens
Here is an argument: "There has been testimony from one to five persons every year for the past twenty-five years that unidentified flying objects have been piloted by extraterrestrials. Therefore, unidentified flying objects have been piloted by extraterrestrials." Now suppose this argument is modified by adding the premise that half of this testimony has been from people who are mentally unstable. That modification will cause the argument's inductive strength to be
weaker because testimony from mentally unstable people is less believable.
