Critical Thinking Exam 2

Question phrasing

should be neutral and not emotionally charged.

Restricted choices

similar to the 'false dilemma' fallacy, the condensing of a broad spectrum of opinions on issues into a few convenient choices.

If today you can make teaching evolution in public schools a crime, then tomorrow you can make it a crime to teach it in private schools. Then you can ban books and other educational materials that mention evolution. And then you can ban the very word from all discourse. And then the anti-science bigots will have won.

slippery slope

Geraldo says that students who cheat on exams should not automatically be expelled from school. But it's ridiculous to insist that students should never be punished for cheating.

straw man

Self-Selecting Sample

type of sample that usually tells you very little about the target population.

Literary Analogies

used to explain or describe something by comparison.

Appeal to the Person (ad hominem)

version of the genetic fallacy that occurs when rejecting a claim by criticizing the person who makes it rather than the claim itself.

Representative sample

In enumerative induction, a sample that resembles the target group in all relevant ways (to the property).

Confidence level

In statistical theory, the probability that the sample will accurately represent the target group within the margin of error.

I'm sure Senator Braxton would never take a large bribe.

Innuendo

"If a single cell, under appropriate conditions, becomes a person in the space of a few years, there can surely be no difficulty in understanding how, under appropriate conditions, a cell may, in the course of untold millions of years, give origin to the human race." (Herbert Spencer]

Is diversity among multiple cases a significant factor? No Is the argument strong or weak? Strong

"If we survey the universe, so far as it falls under our knowledge, it bears a great resemblance to an animal or organized body, and seems actuated with a like principle of life and motion. A continual circulation of matter in it produces no disorder: a continual waste in every part is incessantly repaired: The closest sympathy is perceived throughout the whole system. And each part or member, in performing its proper offices, operates both to its own preservation and to that of the whole. The world, therefore, I infer, is an animal, and the Deity is the soul of the world, activating it and activated by it." [Philo, in Hume's Dialogues Concerning Natural Religion]

Is diversity among multiple cases a significant factor? No Is the argument strong or weak? Weak

"The mass of men serve the State thus, not as men mainly, but as machines, with their bodies. They are the standing army, and the militia, jailers, constables, posse comitatus, &c. In most cases there is no free exercise whatever of the judgment or of the moral sense; but they put themselves on a level with wood and earth and stones, and wooden men can perhaps be manufactured that will serve the purpose as well. Such command no more respect than men of straw, or a lump of dirt." (Henry David Thoreau]

Is diversity among multiple cases a significant factor? No Is the argument strong or weak? Weak

The United Nations failed to intervene in Cambodia to prevent massive human rights violations and ethnic cleansing. It also failed to act to stop the murders of close to a million innocent people in Rwanda. The UN will not intervene to stop any widespread slaughter of innocents in Nigeria.

Is diversity among multiple cases a significant factor? No Is the argument strong or weak? Weak

The casinos in Atlantic City have brought a tremendous amount of revenue into both area businesses and local government, without inviting the evils of organized crime and causing the degradation of law and order or quality of life. The same can be said for the Turning Stone casino in upstate New York, as well as for Casino Niagara in Niagara Falls, Canada. A casino built in Buffalo, New York, will provide all the same benefits without the disadvantages.

Is diversity among multiple cases a significant factor? No Is the argument strong or weak? Weak

Either John drove home or he stayed late. He didn't drive home. Therefore, he stayed late.

This argument is Valid. The form of this argument is Disjunctive syllogism.

If it rains, Alex will get wet. If Alex gets wet, he will be upset. Therefore, if it rains, Alex will be upset.

This argument is Valid. The form of this argument is Hypothetical syllogism.

If the butler didn't kill the master, then the maid did. The butler didn't kill him. So the maid killed him.

This argument is Valid. The form of this argument is Modus ponens.

If laws could stop crime, there would be no crime. But there is crime.Therefore, laws cannot stop crime. This argument is Valid .

This argument is Valid. The form of this argument is Modus tollens.

A national polling organization surveys fifteen hundred obstetrician gynecologists chosen randomly from a national registry of this medical specialty. The survey question is whether obstetrician-gynecologists provide quality care for pregnant women. Ninety-eight percent of those surveyed say yes. The pollsters conclude that almost all physicians think that obstetrician-gynecologists provide quality care for pregnant women.

Unrepresentative sample

A national women's magazine publishes a questionnaire on sexual harassment in the workplace. Respondents are asked to complete the questionnaire and mail it in to the magazine. The magazine receives over twenty thousand completed questionnaires in the mail. Sixty-two percent of the respondents say that they've been sexually harassed at work. The magazine reports that most women have been sexually harassed at work.

Unrepresentative sample; Nonrandom sampling

Anita conducts a survey to determine if Americans are willing to support the arts by contributing money directly to local theater groups. One night she and her assistants interview five hundred people who are attending a performance of a musical at the city's biggest theater. To help ensure random selection, they purposely select every other patron they encounter for interviewing. There is only one interview question: "Are you willing to support the arts by giving money to local theater groups? Ninety-four percent of the interviewees answer yes. Anita later reports that a large majority of Americans are willing to support the arts by giving money to local theater groups.

Unrepresentative sample; Nonrandom sampling

All rectangles are squares. All rectangles are parallelograms. Therefore, all parallelograms are squares. What is the Form?

All R are S. All R are P. All P are S

Relevant property

(or property in question)—In enumerative induction, a property, or characteristic, that is of interest in the target group.

Sample

(or sample member)—In enumerative induction, the observed members of the target group.

Target group

(or target population)—In enumerative induction, the whole collection of individuals under study.

Analogy

A comparison of two or more things alike in specific respects.

Random sample

A sample that is selected randomly from a target group in such a way as to ensure that the sample is representative.

Seventy-seven percent of adults interviewed in three Philadelphia shopping malls (650 people) say they will vote Democratic in the next presidential election.

A substantial percentage of people who shop at malls in Philadelphia will vote Democratic in the next presidential election.

All squares are parallelograms. All rectangles are parallelograms. Therefore, all squares are rectangles. Which one of the following correctly expresses the form of the argument?

All S are P. All R are P. All S are R.

All squares are triangles. All triangles are circles. Therefore, all circles are squares. Which one of the following correctly expresses the form of the argument?

All S are T. All T are C. All C are S.

Modus Ponens (Affirming the Antecedent)

Also known as "affirming the antecedent."Arguments of this general form are always valid: If p, then q. p. Therefore, q.

Statistical Syllogism

An argument pattern in which the inference goes from a statement about a group of things to a conclusion about a single member of that group.

Enumerative Induction

An inductive argument pattern in which we reason from premisesabout individual members of a group to conclusions about the group as a whole.

Genetic Fallacy

Arguing that a claim is true or false solely because of its origin.

Composition

Arguing that what is true of the parts must be true of the whole.

Division

Arguing that what is true of the whole must be true of the parts.

Denying the Antecedent

Arguments of this form are always not valid: If p, then q. Not p. Therefore, not q.

Affirming the Consequent

Arguments of this form are always not valid: If p, then q. q. Therefore, p.

Disjunctive Syllogism

Arguments of this general form are always valid: Either p or q. Not p. Therefore, q.

Hypothetical Syllogism

Arguments of this general form are always valid: If p, then q. If q, then r. Therefore, if p, then r.

Modus Tollens (Denying the Consequent)

Arguments of this general form are always valid: If p, then q. Not q. Therefore, not p.

Reductio ad absurdum (indirect proof)

Assume p. If p then q. But not q. Therefore, not p.

By listening to music, 43 percent of arthritis patients at the Drexell Clinic experience a decrease in pain in their knee and finger joints.

By listening to music, some arthritis patients at the Drexell Clinic can experience a decrease in pain in their knee and finger joints.

Four out of five of the college's English majors hate anything written by William Faulkner.

Eighty percent of the college's English majors hate anything written by William Faulkner.

No squares are circles. No triangles are circles. It follows that no squares are triangles. Which one of the following correctly expresses the form of the argument?

No S are C. No T are C. No S are T.

A lot of people think that football jocks are stupid and boorish. That's a crock. Anyone who had seen the fantastic game that our team played on Saturday, with three touchdowns before halftime, would not believe such rubbish.

red herring

Counterexample to a statement

Provides evidence that a statement is false

All rectangles are squares. All rectangles are parallelograms. Therefore, all parallelograms are squares. Which one of the following substitutions shows the argument invalid?

R = puppies, S = dogs, and P = mammals

All squares are parallelograms. All rectangles are parallelograms. Therefore, all squares are rectangles. Which one of the following substitutions shows the argument invalid?

S = cats, P = mammals, and R = dogs

All squares are triangles. All triangles are circles. Therefore, all circles are squares. Which one of the following substitutions shows the argument invalid?

S = puppies, T = dogs, and C = mammals

A prominent sociologist wants to determine the sexual attitudes of women aged twenty-five to forty-five. The main question to be explored is whether heterosexual women in this age group feel satisfied with their partners' sexual performance. The sociologist interviews two hundred of her friends who belong to the target group. She also asks two hundred of her female colleagues at her college to complete and return a survey asking the key question. She gets seventy-eight completed surveys back from women in the target group. She finds that 75 percent of all the interviewees say that they are not satisfied with their partners' performance. She concludes that most heterosexual women aged twenty-five to forty-five aren't happy with the sexual performance of their partners.

Sample too small; Unrepresentative sample; Nonrandom sampling

Counterexample to an argument

Shows that true premises do not make the conclusion necessarily true (argument is invalid)

Alonzo has been driving his Dodge Spirit for seven years without any problems. His friend has the same kind of car and has been driving it for five years trouble-free.

Some Dodge Spirits are trouble-free cars.

"The most blatant occurrence of recent years is all these knuckleheads running around protesting nuclear power-all these stupid people who do not research at all and who go out and march, pretending they care about the human race, and then go off in their automobiles and kill one another." [Ray Bradbury]

Stereotyping

Both domestic cats that I have observed have teeth. Therefore, all domestic cats have teeth.

Target group = all domestic cats Sample = two domestic cats (sample size 2) Relevant property = having teeth

All the corporate executives Jacques has worked for have been crooks.Therefore, all corporate executives are probably crooks.

Target group = corporate executives Sample = the corporate executives Jacques has worked for Relevant property = being a crook

Hasty generalization

The fallacy of drawing a conclusion about a target group based on an inadequate sample size.

Margin of error

The variation between the values derived from a sample and the true values of the whole target group.

If ESP (extrasensory perception) were real, psychic predictions would be completely reliable. Psychic predictions are completely reliable. Therefore, ESP is real.

This argument is Invalid. The form of this argument is Affirming the consequent.

If I perceive what appears to be a red door, then there really is a red door there. There really is a red door there. Therefore, I perceive what appears to be a red door.

This argument is Invalid. The form of this argument is Affirming the consequent.

If the South Africans have nuclear weapons, the South African jungle will be radioactive. The South African jungle is radioactive. Therefore, the South Africans have nuclear weapons.

This argument is Invalid. The form of this argument is Affirming the consequent.

If ESP (extrasensory perception) were real, psychic predictions would be completely reliable. ESP is not real. Therefore, psychic predictions are not completely reliable.

This argument is Invalid. The form of this argument is Denying the antecedent.

If the South Africans have nuclear weapons, the South African jungle will be radioactive. The South Africans do not have nuclear weapons. Therefore, the South African jungle is not radioactive.

This argument is Invalid. The form of this argument is Denying the antecedent.

Professor, I deserve a better grade than a Don my paper. Look, my parents just got a divorce. If they see that I got a D, they will just blame each other, and the fighting will start all over again. Give me a break.

appeal to emotion

The new StratoCar is the best automobile on the road. Picture the admiring glances you'll get when you take a cruise in your StratoCar through town. Imagine the power and speed!

appeal to emotion

Gremlins exist, that's for sure. No scientist has ever proved that they don't exist.

appeal to ignorance

I don't believe in heaven and hell because no one-not even scientists, has ever produced proof that they exist.

appeal to ignorance

Is the theory of evolution true? Yes. Polls show that most people believe in it.

appeal to popularity

John is now on trial for murder, but the proceedings are a waste of time and money. Everyone knows he's guilty.

appeal to popularity

The federal budget deficits are destroying this country. Just ask any working stiff; he'll tell you.

appeal to popularity

The prime minister is lying about his intelligence briefings since almost everyone surveyed in national polls thinks he's lying.

appeal to popularity

Anthony argues that capital punishment should be abolished. But why should we listen to him? He's a prisoner on death row right now.

appeal to the person

The arguments of right-to-lifers cannot be believed. They're hypocrites who scream about dead babies but then murder abortion doctors.

appeal to the person

The hippies of the sixties railed against the materialistic, capitalistic system and everyone who prospered in it. But all their bellyaching was crap because they were a bunch of hypocrites, living off their rich mothers and fathers.

appeal to the person

Does acupuncture work? Can it cure disease? Of course. It has been used in China by folk practitioners for at least three thousand years.

appeal to tradition

Of course the death penalty is a just punishment. It has been used for centuries.

appeal to tradition

"Look around the world: contemplate the whole and every part of it: you will find it to be nothing but one great machine, subdivided into an infinite number of lesser machines, which again admit of subdivisions, to a degree beyond what human senses and faculties can trace and explain. All these various machines, and even their most minute parts are adjusted to each other with an accuracy, which ravishes into admiration all men who have ever contemplated them. The curious adapting of means to ends, throughout all nature, resembles exactly, though it much exceeds, the production of human contrivance; of human design, thought, wisdom, and intelligence. Since therefore the effects resemble each other, we are led to infer, by all the rules of analogy, that the causes also resemble; and that the Author of Nature is somewhat similar to the mind of men; though possessed of much larger faculties, proportioned to the grandeur of the work, which he has executed. By this argument a posteriori, and by this argument alone, do we prove at once the existence of a Deity, and his similarity to human mind and intelligence." (David Hume]

argument by analogy

How does one know that there exist in the world other minds-that is, others having feelings and other subjective experiences? One can observe that one's own experiences are connected to publicly observable phenomena, that other people exhibit publicly observable phenomena, and therefore other people also must have subjective experiences. For example, one may observe that when one stubs a toe, one feels pain and cries "ouch." Then if other people—who are physically similar to oneself-also stub their toes and cry "ouch," one can conclude that they also experience pain.

argument by analogy

Tolerating a vicious dictator is like tolerating a bully on the block. If you let the bully push you around, sooner or later he will beat you up and take everything you have. If you let a dictator have his way, he will abuse his people and rob them of life and liberty. If you stand up to the bully just once or-better yet-knock him senseless with a stick, he will never bother you again. Likewise, if you refuse to be coerced by a dictator or if you attack him, his reign will be over. Therefore, the best course of action for people oppressed by a dictator is to resist and attack.

argument by analogy

Fallacy

argument form that is both common and defective; a recurring mistake in reasoning.

Faulty Analogy

argument in which the things being compared are not sufficiently similar in relevant ways.

Argument by analogy

argument making use of analogy, reasoning that because two or more things are similar in several respects, they must be similar in some further respect.

Opinion Polls

assessments of public opinion obtained by questioning a representative sample.

Random drug testing in schools is very effective in reducing drug use because the regular use of the testing makes drug use less likely.

begging the question

Three thieves are dividing up the $7,000 they just stole from the First National Bank. Robber number one gives $2,000 to robber number two, $2,000 to robber number three, and $3,000 to himself. Robber number two says, "How come you get $3,000?" Robber number one says, "Because I am the leader." "How come you're the leader?" "Because I have more money."

begging the question

Every player on the team is the best in the league. So the team itself is the best in the league.

composition

If you have a single straw, it is not a heap. The addition of another straw does not make it a heap. So because there is no clear delineation as to what quantifies a "heap," there will never be such thing as a "heap."

decision-point fallacy

My sweater is blue. Therefore, the atoms that make up the sweater are blue.

division

Biased sample

does not properly represent the target group.

Question ordering

e.g., putting a negative question before a positive question will get different results than putting a positive question before a negative question.

George has loved every Chevrolet he has owned in the past five years. So he will probably love the Chevrolet he bought yesterday.

enumerative induction

Girls are smarter than boys. Girls in the debate club always argue better than boys. And the mean grade-point average of the girls in the glee club is higher than that of the boys in the club.

enumerative induction

Only man has morals. No woman is a man. Therefore, no woman has morals.

equivocation

Bill is an investment banker, drives a Cadillac, is overweight, and votes Republican. John is also an investment banker, drives a Cadillac, and is overweight. So John probably votes Republican, too.

faulty analogy

I met these two guys on a plane, and they said they were from Albuquerque. They were total druggies. Almost everyone in that city must be on drugs.

hasty generalization

"Howard Hughes was able to afford the luxury of madness, like a man who not only thinks he is Napoleon but hires an army to prove it."[Ted Morgan]

literary analogy

"The brain secretes thought as the stomach secretes gastric juice, the liver bile, and the kidneys urine." [Karl Vogt]

literary analogy

"The moon was a ghostly galleon tossed upon cloudy seas." (Alfred Noyes]

literary analogy

Irrelevant premises

no bearing on the truth of the conclusion.