Chapter 3 & 5 & 6.1: Deductive Reasoning, Inductive Reasoning, Deduction & Induction

Which of the following is a valid argument?

"All dogs are mammals. Rover is a dog. Therefore, Rover is a mammal."

In the statement "No politicians are honest," which is the predicate term and which is the subject term?

"Politicians" is the subject term, and "honest" is the predicate term. (In a statement "No A are B," the first term, A, is the subject term, and the second term, B, is the predicate term. We sometimes have to put a noun after it to make it clear that we are talking about a class of things, in this case we could say that the predicate class is "honest people."

Argument from Authority

(Appeal to Authority) An argument in which we infer that something is true because someone (a purported authority) said that it was true.

Trigger Cause

(Proximate Cause) The factor that completes the cause chain resulting in the effect.

A valid argument is...

....an argument in which it is impossible to have true premises and a false conclusion.

"No cats are dogs. Some cats are mammals. Therefore, some dogs are mammals." This argument is...

...a categorical argument

"The two smaller sides of this right triangle have length 3 and 4, so the hypotenuse must have length 5." This argument is...

...a mathematical argument.

A sound argument is...

...a valid argument with true premises.

"She is an adult female human. Therefore, she is a woman." This argument is...

...an argument by definition.

Deductive arguments...

...are intended to be valid. (What it means for an argument to be deductive is that the conclusion is intended to follow (validly) from the premises.)

The counterexample method shows that an argument is invalid by...

...finding an argument of the same form with true premises and a false conclusion.

An argument is deductive...

...if it presents itself as being valid.

When conducting a survey, it is important to choose a sample that...

...is random.

An argument is sound if...

...it is valid and has all true premises. (Deductive soundness means that all of the premises are true and that the argument is deductively valid.)

In logic, arguments are best described as...

...providing reasons for a conclusion.

Inductive arguments are evaluated in terms of...

...strength.

One way to make an inductive argument weaker is to...

...strengthen the conclusion.

An inductive argument whose premises give a lot of support for the truth of its conclusion is said to be...

...strong.

A cogent inductive argument is one in which...

...the argument is strong, and all of the premises are true.

A strong inductive argument is one in which...

...the conclusion is likely to be true if the premises are true.

The margin of error is...

...the likely range of difference that one can expect between the sample and the whole population.

A deductive argument that establishes an absolute connection between the premises and conclusion is called a...

...valid argument.

Which of the following is a statistical syllogism?

80% of students at this school cheer for the team. Julie is a student at this school. So Julie probably cheers for the team. (A statistical syllogism is an argument with the form: X% of S are P. i is an S. Therefore, i is a P. In this case, 'students at this school' is S, and Julie is i. 'People who cheer for the team' is P, and the argument fits the form.)

Sorites

A categorical argument with more than two premises. (A sorites presents a chain of syllogistic arguments. It does so by presenting a syllogistic argument with more than two premises that can link together to form a chain or syllogisms, the conclusion of some forming the premises of others.)

Sufficient Condition

A condition for an even that guarantees that the event will occur; A is a sufficient condition of B if B occurs whenever A does.

Necessary Condition

A condition for an event without which the even will not occur; A is a necessary condition of B if A occurs whenever B does.

Syllogism

A deductive argument with exactly two premises.

Venn Diagram

A diagram constructed of overlapping circles, with shaded areas or x's, which shows the relationships between the represented groups.

Random Sample

A group selected from within the whole population using a selection method such that every member of the population has an equal chance of being included.

Margin of Error

A range of values above and below the estimated value in which it is predicted that the actual result will fall.

Sample

A smaller group selected from among the population.

Categorical Statement

A statement that relates one category or class to another. Specifically, if S and P are categories, the categorical statements relating them are: All S is P, No S is P, Some S is P, and Some S is not P.

Instance

A term in logic that describes the sentence that results from replacing each variable within the form with specific sentences.

Which of the following would be a sound argument?

A valid argument with all true premises.

Method of Concomitant Variation

A way of selecting causal candidates by looking for a factor that is highly correlated with the effect in question.

Joint Method of Agreement and Difference

A way of selecting causal candidates by looking for a factor that is present in all cases in which the effect occurs and absent in all cases in which it does not.

Method of Agreement

A way of selecting causal candidates by looking for a factor that is present in all cases in which the effect occurs.

Method of Difference

A way of selecting causal candidates by looking for a factor that is present when effect occurs and absent when it does not.

This is a method by which one can strengthen an inductive argument.

Adding supporting premises.

Which of the following is the form of "All birds are animals, so some animals are birds"?

All A are B, so some B are A.

The argument "All dogs are mammals. Some mammals are brown. So some dogs are brown" has the form:

All As are Bs. Some Bs are Cs. Therefore, some As are Cs.

Which of the following presents a counterexample to the following argument's validity: "All football players are tough. Some tough people are mean. Therefore, some football players are mean"?

All dogs are mammals. Some mammals are cats. Therefore, some dogs are cats.

Which of the following presents a counterexample to the following argument's validity: "All giraffes are tall. No giraffes are reptiles. Therefore, no reptiles are tall"?

All men are human. No men are women. Therefore, no women are human. (To find a counterexample to an argument's validity is to find another argument of the exact same form but that leads fro true premises to a false conclusion.)

If an argument is valid, which of the following cannot be true?

All of its premises are true and its conclusion is false.

Causal Argument

An argument about causes and effects.

Categorical Argument

An argument entirely composed of categorical statements.

This form of an argument draws a conclusion based on a similarity of the present case to other cases that have something in common with it.

An argument from analogy

Inductive Generalization

An argument in which one draws a conclusion about a whole population based on results from a sample population.

Enthymeme

An argument in which one or more claims are left unstated. (An argument with a missing premise or conclusion. The missing premise is assumed but not explicitly stated. Thesis statements are often expressed as enthymemes. A simple example is "Flipper is a mammal because Flipper is a dolphin." The obvious missing premise is that all dolphins are mammals.)

Argument from Definition

An argument in which one premise is a definition.

Valid

An argument in which the premises absolutely guarantee the conclusion, such that is impossible for the premises to be true while the conclusion is false.

Statistical Syllogism

An argument of the form X% of S are P; i is an S; Therefore, i is (probably) a P.

Deductive Argument

An argument that is presented as being valid - if the primary evaluative question about the argument is whether it is valid.

Correlation

An association between two factors that occur together frequently or that vary in relation to each other.

Cogent

An inductive argument that is strong and has all true premises.

Form of Inductive Reasoning: Psilocybin mushrooms cause hallucinations in humans who ingest them. A new species of mushroom shares similar visual characteristics to many forms of psilocybin mushrooms. Therefore, it is likely that this form of mushroom has compounds that have neurological effects.

Argument from Analogy

Form of Inductive Reasoning: The purpose of ancient towers that were discovered in Italy are unknown. However, similar towers were discovered in Albania, and the historical accounts in that country indicate that the towers were used to store grain. Therefore, the towers in Italy were probably used for the same purpose.

Argument from Analogy

What type of inductive argument is the following example? "I had mincemeat pie once, and it was terrible. So, it will be terrible next time too."

Argument from analogy

What type of inductive argument is the following example? "I liked Chinese food last week, so I will probably like it this time as well."

Argument from analogy

What type of inductive reasoning is the following argument? "My finance guy says that I should put my money in mutual funds, so I should."

Argument from authority.

Immediate Inferences

Arguments from one categorical statement as premise to another as conclusion. In other words, we immediately infer one statement from another.

Inductive Arguments

Arguments in which the premises increase the likelihood of the conclusion being true but do not guarantee that it is.

Statistical Arguments

Arguments involving statistics, either in the premises or in the conclusion.

What does it mean for A to be a sufficient condition for B?

B will be true whenever A is. (A sufficient condition is a factor that guarantees the other. In other words, A is sufficient for B if, whenever A is true, B must be true as well.)

The argument "All dogs are mammals. No dogs are reptiles. So no mammals are reptiles" is which kind of deductive argument?

Categorical Argument (Arguments that discuss categories of things (like dogs) and whose reasoning depends upon the uses of quantifier words like "all," "some," and "no" are part of categorical logic.)

Form of Inductive Reasoning: After the current presidential administration passes a bill that increases the amount of time people can be on unemployment, the unemployment rate in the country increases. Economists studying the bill claim that there is a direct relation between the bill and the unemployment rate.

Causal Argument

Inductive or Deductive: All doctors are people who are committed to enhancing the health of their patients. No people who purposely harm others can consider themselves to be doctors. Therefore, some people who harm others do not enhance the health of their patients.

Deductive

Inductive or Deductive: All dogs are warm-blooded. All warm-blooded creatures are mammals. Hence, all dogs are mammals.

Deductive

Inductive or Deductive: All squares are triangles, and all triangles are rectangles. Therefore, all squares are rectangles.

Deductive

Inductive or Deductive: All voters are residents of California. But some residents of California are Republican. Therefore, some voters are Republican.

Deductive

Inductive or Deductive: Deciduous trees are trees that shed their leaves. Maple trees are deciduous trees. Therefore, maple trees will shed their leaves at some point during the growing season.

Deductive

Inductive or Deductive: If she wanted me to buy her a drink, she would've looked over at me. But she never looked over at me. So that means that she doesn't want me to buy her a drink.

Deductive

Inductive or Deductive: If you drive too fast, you will get into an accident. If you get into an accident, your insurance premiums will increase. Therefore, if you drive too fast, your insurance premiums will increase.

Deductive

Inductive or Deductive: Since all mammals are cold-blooded, and all cold-blooded creatures are aquatic, all mammals much be aquatic.

Deductive

Inductive or Deductive: Since all philosophers are seekers of truth, it follows that no evil human is a seeker after truth, since no philosophers are evil humans.

Deductive

Inductive or Deductive: Some apples are not bananas. Some bananas are things that are yellow. Therefore, some things that are yellow are not apples.

Deductive

Inductive or Deductive: This is not the best of all possible worlds, because the best of all possible worlds would not contain suffering, and this world contains much suffering.

Deductive

Inductive arguments differ from deductive arguments in which of the following ways?

Deductive arguments attempt to guarantee their conclusions and inductive arguments attempt to support their conclusions. (Even in the strongest inductive argument there is a possibility that the conclusion will not be true.)

Deductive or Not: Because all libertarians believe in more individual freedom, all people who believe in individual freedom are libertarians.

Deductive.

Deductive or Not: If Mount Roosevelt was completed in 1940, then it's only 73 years old. Mount Roosevelt is not 73 years old. Therefore, Mount Roosevelt was not completed in 1940.

Deductive.

Deductive or Not: If she wanted me to buy her a drink, she would've looked over at me. But she never looked over at me. So that means that she doesn't want me to buy her a drink.

Deductive.

Deductive or Not: If we save up money for a house, then we will have a place to stay with our children. However, we haven't saved up any money for a house. Therefore, we won't have a place to stay with our children.

Deductive.

Deductive or Not: No dogs are fish. Some guppies are fish. Therefore, some guppies are not dogs.

Deductive.

Deductive or Not: No physical object can travel faster than light. An electron is a physical object. So an electron cannot travel faster than light.

Deductive.

Deductive or Not: Pigs are smarter than dogs. Animals that are easier to train are smarter than other animals. Pigs are easier to train than dogs.

Deductive.

Deductive or Not: Triangle A is congruent to triangle B. Triangle A is an equilateral triangle. Therefore, triangle B is an equilateral triangle.

Deductive.

Deductive or Not: You're either with me, or you're against me. You're not with me. Therefore, you're against me.

Deductive.

Sound

Describes an argument that is valid and in which all the premises are true.

True or False: Deductive arguments always reason from the general to the specific.

FALSE.

True or False: Inductive arguments always reason from the specific to the general.

FALSE.

True or False: If two things are positively correlated with one another then one of them must be the cause of the other.

FALSE. A correlation can have many possible explanations. One other possibility is that there is a third thing that is causing both. In this case they might be positively correlated without either one causing the other.

True or False: A sorites is an argument with a missing (but intended) premise.

FALSE. A sorites is a string of syllogistic arguments. An enthymeme is one with a missing (but intended) premise or conclusion.

True or False: A statistical syllogism is an argument in which one draws a general conclusion from statistical results about a sample population.

FALSE. A statistical syllogism is an argument in which one reasons from a statistical claim about a general population (like 97% of dogs like bones) to a probable claim about an individual member of that population (like Fido probably likes bones).

True or False: Appeals to authority are always fallacious.

FALSE. Appeals to authority often provide strong inductive evidence (e.g., a legitimate authority stating observations about a field of his or her expertise).

True or False: Arguments from definitions are inductive since they rely on dictionaries.

FALSE. Arguments fro definitions are a common type of deductive reasoning.

True or False: For an inductive argument to be strong means that it is impossible for the premises to be true and the conclusion false.

FALSE. For an inductive argument to be strong means that the truth of the premises would make it very unlikely that the conclusion is false. If it were impossible then the argument would be deductive and valid.

True or False: An inductive generalization with a large sample is bound to have a true conclusion.

FALSE. In addition to having a large sample size, it is important that inductive generalizations (in which one reasons from a claim about a sample to a claim about a larger population), also is unbiased in its sampling methods.

True or False: The argument "All dogs are mammals. Some mammals are brown. So some dogs are brown" is logically valid.

FALSE. The argument is invalid, as can be determined with Venn diagrams or the rules for syllogistic validity. There is a possibility that all of the brown mammals are in the non-dog category.

True or False: The argument "All ducks are birds. No birds are reptiles. Therefore, no reptiles are birds" has the form "All As are Bs. No Bs are Cs. Therefore, no As are Cs."

FALSE. This form is close, but the argument's form should be written "All As are Bs. No Bs are Cs. Therefore, no Cs are As."

True or False: The number of similarities between two phenomena or occurrences does not matter when using analogical induction.

FALSE. When using analogies to draw inductive conclusions, it is extremely important that the two things that are being compared in the analogy have as many similar characteristics as possible. When the two things do not share enough similarities the analogy is faulty.

Complement Class

For a given class, the complement class consists of all things that are not in the given class. For example, if S is a class, its complement class is non-S.

Which of the following can weaken an inductive generalization?

Having a small sample size. (An inductive generalization draws a conclusion about a larger population based on results from a sample population. The argument will be weak if the sample is too small. Randomness of the sample is actually a good thing.)

Which of the following is a strong argument from analogy?

I have ordered Sushi many times, and I have always hated it. Therefore, I will hate it this time, too. (An argument from analogy reasons from observed examples to a new case that resembles them. Two arguments among these options fit that form. Only one is strong.)

Confidence Level

In an inductive generalization, the likelihood that a random sample from a population will have results that fall within the estimated margin of error.

Population

In an inductive generalization, the whole group about which the generalization is made; it is the group discussed in the conclusion.

Quality

In logic, the distinction between a statement being affirmative or negative.

Quantity

In logic, the distinction between a statement being universal or particular.

Inductive or Deductive: Almost all the people I know who are translators have their translator's license from the ATA. Carla is a translator. Therefore, she must have a license from the ATA.

Inductive

Inductive or Deductive: Chances are that I will not be able to get in to see Slipknot since it is an over 21 show, and Jeffrey, James, and Sloan were all carded when they tried to get in to the club.

Inductive

Inductive or Deductive: Dogs are better than cats, since they always listen to what their masters say. They also are more fun and energetic.

Inductive

Inductive or Deductive: Every time I turn on the radio, all I hear is vulgar language about sex, violence, and drugs. Whether it's rock and roll or rap, it's all the same. The trend toward vulgarity has to change. If it doesn't, younger children will begin speaking in these ways and this will spoil their innocence.

Inductive

Inductive or Deductive: Football is the best sport. The athletes are amazing, and it is extremely complex.

Inductive

Inductive or Deductive: Guns are necessary. Guns protect people. They give people confidence that they can defend themselves. Guns also ensure that the government will not be able to take over its citizenry.

Inductive

Inductive or Deductive: I felt fine until I missed lunch. I must be feeling tired because I don't have anything in my stomach.

Inductive

Inductive or Deductive: I know that Stephen has a lot of money. His parents drive a Mercedes. His dogs wear cashmere sweaters, and he paid cash for his Hummer.

Inductive

Inductive or Deductive: Joe must make a lot of money teaching philosophy, since most philosophy professors are rich.

Inductive

Inductive or Deductive: Justin was working at IBM. The last person we got from IBM was a horrible worker. I don't think that it's a good idea for us to go with Justin for this job.

Inductive

Inductive or Deductive: Letting your kids play around on the Internet all day is like dropping them off in downtown Chicago to spend the day by themselves. They will find something that gets them into trouble.

Inductive

Inductive or Deductive: Pigs are smarter than dogs. It's easier to train them.

Inductive

Inductive or Deductive: Seventy percent of the students at this university come from upper-class families. The school budget has taken a hit since the economic downturn. We need funding for the three new buildings on campus. I think it's time for us to start a phone campaign to raise funds so that we don't plunge into bankruptcy.

Inductive

Inductive or Deductive: The economy continues to descend into chaos. The stock market still moves down after it makes progress forward, and unemployment still hovers around 10%. It is going to be a while before things get better in the US.

Inductive

Inductive or Deductive: The economy will not recover anytime soon. Big businesses are struggling to keep their profits high. This is due to the fact that consumers no longer have enough money to purchase things that are luxuries. Most of them buy only those things that they need and don't have much left over. Those same businesses have been firing employees left and right. If America's largest businesses are losing employees, then there won't be any jobs for the people who are already unemployed. That means that these people will not have money to pump back into the system, and the circle will continue to descend into recession.

Inductive

Inductive or Deductive: Too many intravenous drug users continue to risk their lives by sharing dirty needles. This situation could be changed if we were to supply drug addicts with a way to get clean needles. This would lower the rate of AIDS in this high-risk population as well as allow for the opportunity to educate and attempt to aid those who are addicted to heroin and other intravenous drugs.

Inductive

Inductive or Deductive: We should go to see Avatar tonight. I hear that it has amazing special effects.

Inductive

Form of Inductive Reasoning: A family is committed to buying Hondas because every Honda they have owned has had few problems and been very reliable. They believe that all Hondas must be reliable.

Inductive Generalization

Form of Inductive Reasoning: A recent survey at work indicates that 60% of the employees believe that they do not make enough money for the work that they do. It is likely that a majority of the people that work for this company are unhappy in their jobs.

Inductive Generalization

Form of Inductive Reasoning: In the state of California, studies found that violent criminals who were released on parole had a 68% chance of committing another violent crime. Therefore, a majority of violent criminals in society are likely to commit more violent crimes if they are released from prison.

Inductive Generalization

Form of Inductive Reasoning: When studying a group of electricians, it was found that 60% of them did not have knowledge of the new safety laws governing working on power lines. Therefore, 60% of the electricians in the US probably do not have knowledge of the new laws.

Inductive Generalization

Strong Arguments

Inductive arguments in which the premises greatly increase the likelihood that the conclusion is true.

Weak Arguments

Inductive arguments in which the premises only minimally increase the likelihood that the conclusion is true.

What type of inductive argument is the following example? "Every cat I've tested hates citrus. Therefore, all cats hate citrus."

Inductive generalization

What type of inductive argument is the following example? The majority of people surveyed prefer strawberry to chocolate Therefore, most people prefer strawberry to chocolate

Inductive generalization

Which of the following is true about inductive reasoning versus deductive reasoning?

Inductive reasoning is sometimes preferable.

Inductive or Deductive: Many people today claim that men and women are basically the same. Although I believe that men and women are equally capable of completing the same tasks physically as well as mentally, to say that they are intrinsically the same detracts from the differences between men and women that are displayed every day in their social interactions, the way they use their resources, and the way in which they find themselves in the world.

Inductive.

Which of the following is something that can make a statistical syllogism weak?

It has a poorly chosen reference class. (A poorly chosen reference class means that the individual in question is less likely than the average member of the group to have the characteristic in question. This makes the argument weak because the conclusion is less likely to be true even if the premises are true.)

What does it mean for an argument to be invalid?

It is possible for all of its premises to be true and its conclusion is false.

Which of the following statements is true of this argument: "All dogs are mammals. No mammals are reptiles. So no dogs are reptiles"?

It is valid, as shown by the rules and by the Venn diagram.

Which of the following statements is true of this argument: "Some politicians are nice. No politicians are honest. So some nice people are dishonest"?

It is valid, as shown by the rules and by the Venn diagram. (The argument is valid. Venn diagrams and the rules for valid syllogisms both show that it is impossible for the premises to be true and the conclusion false for any argument of this form.)

Deductive or Not: A nation is only as great as its people. The people are reliant on their leaders. Leaders create the laws in which all people can flourish. If those laws are not created well, the people will suffer. This is why the people of the US are currently suffering.

NOT.

Deductive or Not: Charles is hard to work with, since he always interrupts others. Therefore, I do not want to work with Charles in the development committee.

NOT.

Deductive or Not: Our dogs are extremely sick. I have to work every day this week, and our house is a mess. There's no way I'm having my family over for Festivus.

NOT.

Deductive or Not: Paying people to mow your lawn is not a good policy. When people mow their own lawns, they create self-discipline. In addition, they are able to save a lot of money over time.

NOT.

Deductive or Not: Seventy percent of the students at this university come from upper class families. The school budget has taken a hit since the economic downturn. We need funding for the three new buildings on campus. I think it's time for us to start a phone campaign to raise funds so that we don't plunge into bankruptcy.

NOT.

Deductive or Not: The farmers in Poland have produced more than 500 bushels of wheat a year on average for the past 10 years. This year they will produce more than 500 bushels of wheat.

NOT.

Deductive or Not: The study of philosophy makes your soul more slender, healthy, and beautiful. You should study philosophy.

NOT.

Deductive or Not: The worldwide use of oil is projected to increase by 33% over the next 5 years. However, reserves of oil are dwindling at a rapid rate. That means that the price of oil will drastically increase over the next 5 years.

NOT.

Deductive or Not: Walking is great exercise. When people exercise they are happier and they feel better about themselves. I'm going to start walking 4 miles every day.

NOT.

Deductive or Not: We have to focus all of our efforts on marketing because right now; we don't have any idea of who our customers are.

NOT.

Deductive or Not: We should go to the beach today. It's sunny. The dolphins are out, and I have a bottle of fine wine.

NOT.

If A and B are shown to be positively correlated then what follows logically?

One does not know the explanation without further investigation. (The options that A causes B, B causes A, or that a third thing is causing both are not necessarily the case. We would need to look for more evidence of the causal correlation.)

Which of the following is NOT one of the key factors in the strength of arguments from analogy?

One has the sense that this case is likely to be true as well. (How may cases one has observed and how similar the present case to those past cases are very relevant to the strength of the analogy. One's 'sense' of likelihood is less likely to be a rational consideration.)

The statement "Some A are not B" has the following quantity and quality:

Particular Negative (The statement is particular because it talks about some. It is negative because it says "not.")

Argument from Analogy

Reasoning in which we draw a conclusion about something based on characteristics of other similar things.

Distribution

Referring to members of groups. If all the members of a group are referred to, the term that refers to that group is said to be distributed.

Which of the following attributes might negatively influence the data drawn from the following samples?: A researcher for Apple analyzes a large group of tribal people in the Amazon to determine which new apps she should create in 2014.

Representativeness of the sample

Which of the following attributes might negatively influence the data drawn from the following samples?: A teacher surveys the gifted students in the district about the curriculum that should be adopted at the high school.

Representativeness of the sample

Which of the following attributes might negatively influence the data drawn from the following samples?: A researcher on a college campus interviews 10 students after a yoga class about their drug use habits and determines that 80% of the student population probably smokes marijuana.

Sample size and Representativeness of the sample

Which of the following is NOT a common type of deductive argument?

Scientific arguments. (Scientific arguments are generally not deductive by inductive.)

Which of the following arguments has this form: "Some As are Bs. No Bs are Cs. Therefore, some As are not Cs"?

Some bleegs are blurgs. No blurgs are greebs. Therefore, some bleegs are not greebs. (To find the instance of the form, replace A with bleegs, B with blurgs, and C with greebs.)

Which of the following is true of the distinction between induction and deduction?

Some forms of inductive reasoning go from the specific to the general, while others go from the general to the specific.

What type of inductive argument is the following example: 96% of teenagers like rock and roll music Mike is a teenager So, Mike probably likes rock and roll music

Statistical syllogism

What type of inductive argument is the following example? "Most people who play the slots lose. Mike is playing the slots, so he is probably losing."

Statistical syllogism

Which of the following is a method of making an inductive argument stronger?

Strengthen the premises. (Strengthening the premises makes the argument stronger. If the premises make stronger claims, it is more likely that the conclusion is true if the premises are true.)

True or False: One way to strengthen an inductive argument would be to provide more premises that provide more evidence for the truth of the conclusion.

TRUE. Adding premises can indeed make an inductive argument go from weak to strong by providing more evidence that the conclusion is true.

True or False: An inductive argument is one that supports its conclusion in a probabilistic fashion.

TRUE. Deductive arguments attempt to guarantee their conclusions. However, in inductive arguments, the conclusions do not necessarily follow. Instead, the premises support their conclusions in a probable fashion.

True or False: Using Mill's methods, if two cases both have the effect and they both have a certain factor then that factor may be related to the cause of the effect.

TRUE. If two people get food poisoning, and they both ate coleslaw, then Mill's method of agreement suggests that the coleslaw becomes a candidate for the cause of the poisoning.

True or False: The statement "No zebras are mammals" is a universal negative.

TRUE. The statement is universal because it talks about all things in a category; it is negative because it uses the word "No" to say that none of them have the predicate.

True or False: Suppose someone gives an argument. Then suppose that there is another argument with the same form as the first, but that has all true premises and a false conclusion. This shows that the first argument is logically invalid.

TRUE. Using the counterexample method, showing that another argument with the same form can have true premises and a false conclusion, shows that the first argument does not have a valid form.

True or False: A valid deductive argument can have false premises.

TRUE. Validity in deductive argumentation has to do with the structure of an argument. A valid argument can have false premises. The one limitation is that in a valid deductive argument, if the premises are true, the conclusion must be true.

If a factor passes the method of agreement and the method of difference, then what does Mill's methods say about that factor?

That factor may be causally related to the effect in question. (Mill's methods of agreement and difference are meant to find factors that have a likelihood of causing the effect in question. A factor that passes is not definitely the cause but is possibly a causal factor.)

Categorical Logic

The branch of deductive logic that is concerned with categorical arguments.

If an inductive argument is strong, then what do we know about the conclusion?

The conclusion is likely to be true if the premises are true. (An inductive argument might be strong yet have an unlikely conclusion if a premise is false What it means for the argument to be strong is that if the premises are true then the conclusion is likely to be true.)

To pass Mill's method of agreement, what must be true about a factor?

The factor has to be present whenever the effect is present. (The method of agreement tests cases in which the effect is present, and if the factor is present in all such cases then the factor passes the test. This does not prove that the factor is the cause, but it does suggest it as a possibility.)

Subject Term

The first term in a categorical proposition.

Contraposition

The immediate inference obtained by switching the subject and predicate terms with each other and complementing them both.

Conversion

The immediate inference obtained by switching the subject and predicate terms with each other.

Counterexample Method

The method of proving an argument form to be not valid by constructing an instance of it with true premises and a false conclusion.

Sample Size

The number of individuals within the sample.

Logical Form

The pattern of an argument or claim.

Which of the following is NOT one of the factors that strengthens an argument from authority?

The person has been right before. (Having been right before is not one of the factors that is listed as a way to strengthen an appeal to authority. Most people can be shown to have been right before about any number of things. Some important elements of strong appeals to authority is that the person is an actual authority, is being honest in the context, and is being interpreted correctly.)

Which of the following is NOT one of the correct descriptions of what it means for an argument to be valid?

The reasoning is correct and all the premises are in fact true.

What is wrong with the following argument: "Most of the people in my state are voting for candidate A, so candidate A will probably become the next president"?

The sample is likely to be biased. (The sample is the people of a whole state, so it is a large sample. The problem is that populations of individual states often do not reflect the views of the whole population of the country. Therefore, the population of one state presents a sample that is likely to be biased relative to the whole population.)

Predicate Term

The second term in a categorical proposition.

What is most likely the problem with the following appeal to authority? "The stock market is going to crash this year; my mechanic said so."

There is no evidence that the mechanic is an expert in the subject matter. (In this case given, this is the kind of thing that would be very hard to predict, and there is no evidence given that the mechanic is actually an authority on the subject at hand.)

In logic, which of the following is NOT true of all deductive arguments?

They reason from general to particular

Which of the following is a method of making an inductive argument stronger?

Weaken the conclusion so that it is more likely to be true. (Weakening the conclusion by adding words like "some," "usually," or "possibly" makes the conclusion more likely to be true and therefore makes the argument stronger.)