PHIL Exam 1

1 All those books have more than more than 200 pages. 2 And all these books here have more than 500 pages. So you can see, 3 there are certainly books that have more than 150 pages.

1 and 2 arrow separately down to 3

1 Every insect has six legs. 2 What's crawling on me is an insect. So 3 what's crawling on me has six legs.

1 and 2 joined and arrow down to 3

1 Last week, when my car would not start, Mom took me to get a new battery. 2 As soon as I installed it, my car started right up. So, 3 my old battery was probably defective.

1 and 2 joined and arrow down to 3

1 Omar spent a third of his yearly income on his car. 2 Mengyu spent half of her yearly income on her car. So, 3 Omar spent more money on his car than Mengyu.

1 and 2 joined and arrow down to 3

We will assume that every statement is either true or false, and never both; these two possibilities are called "truth values"

True

Most horses can run a mile in under 3 minutes. Evie has a horse. Therefore, Evie's horse probably can run a mile in under 3 minutes.

inductive

I am eating a banana; therefore, I am eating a fruit.

missing premise: all bananas are fruit

For the following enthymeme, determine the missing premise so that the argument can be seen to be valid. Reference: Ref 3-2 I am talking to a human; so, I am talking to a mammal.

missing premise: all humans are mammals

Anyone who is an accountant is good at math; so, my aunt is good at math.

missing premise: my aunt is an accountant

Hamburgers are loaded with saturated fat and sodium. Pizza is loaded with saturated fat and sodium. Too much saturated fat and sodium is harmful to your heart. Jim takes in too much saturated fat and sodium. It follows Jim is harming his heart. /// Jim is harming his heart.

conclusion

When premises are independent, the falsity of any one would weaken the support the others give to the conclusion.

false

an argument must have at least two premises

false

an inductive argument is one in which the inferential claim is that, whenever the premises are true, the conclusion must be true as well

false

every explanation is an argument

false

Most people over 18 are registered to vote. Lisa is 19 years old. So, Lisa is registered to vote.

strong

There are thirty students in my class. Two students got a perfect score on the last exam. I am probably one of the students who got a perfect score on the last exam.

weak

Under what circumstance can we call an argument "TRUE"?

Under no circumstances: "true" only applies to statements, never to arguments.

An inductive argument is cogent when the argument is strong, even if the premises are false

false

In a valid argument, all premises are true.

false

In an invalid argument, at least one of the premises is false.

false

Premises are dependent when they are all true at the same time.

false

Some terms have an extension but no intension.

false

The extension of a term is specified by listing the properties or attributes that the term connotes.

false

A single premise can be used to support independent conclusions.

true

A single counterexample to a deductive argument is enough to show that an argument is invalid

true

In a cogent argument, all premises are true.

true

When we are confronted with an argument we first determine the inferential claim to decide whether the argument is deductive or inductive. Only then do we ask one (and only one) of these questions: If the argument is deductive, we ask: "Is the argument valid?" If the argument is inductive, we ask: "Is the argument strong?" We never ask of an inductive argument whether it is valid, nor of a deductive argument whether it is strong. Doing so would make little sense. Characterizing an argument as deductive does not mean saying that it is valid. Characterizing an argument as deductive only means identifying the inferential claim as such. There are invalid deductive arguments after all.

true

What do we call a deductive argument in which it can never be the case that all of the premises are true and the conclusion is false?

valid

What do we call an argument in which one or more premises and/or the conclusion are missing?

enthymeme

The vast majority of students who don't have a book for the course, and who don't do the homework, wind up failing the course. I know for a fact that Stan doesn't have a book and he doesn't do the homework. Stan will fail the course.

strong

A valid deductive argument is one where, assuming the premises are true, it is impossible for the conclusion to be false

true

An deductive argument is one in which the inferential claim is that the conclusion follows necessarily from the premises.

true

An invalid argument is automatically an unsound argument.

true

Premises are dependent when they act together to support a conclusion.

true

Some terms have an intension but no extension.

true

I have a stomach ache. It must be those nachos I ate.

explanation

1 The exam's range of A scores is 90-100. 2 I got a 98 on the exam. It follows necessarily that 3 I got an A on the exam.

1 and 2 joined and arrow down to 3

1 Stealing someone's personal property is illegal. 2 Stealing someone's intellectual property is illegal. So, 3 you should respect all kinds of property. 4 This respect will lead to a more civil society.

1 and 2 joined and arrow down to 3, which arrows down to 4

1 I am eating an orange. 2 So, I am eating something with seed, because 3 every orange has seeds.

1 and 3 joined and arrow down to 2

Hamburgers are loaded with saturated fat and sodium. Pizza is loaded with saturated fat and sodium. Too much saturated fat and sodium is harmful to your heart. Jim takes in too much saturated fat and sodium. It follows Jim is harming his heart. //// Jim takes in too much saturated fat and sodium.

premise

Hamburgers are loaded with saturated fat and sodium. Pizza is loaded with saturated fat and sodium. Too much saturated fat and sodium is harmful to your heart. Jim takes in too much saturated fat and sodium. It follows Jim is harming his heart. ///// Hamburgers are loaded with saturated fat and sodium

premise

Only a few people will be chosen for the Olympic team. Of those receiving phone calls from the selection committee, 80% will make the team. John received a phone call from the selection committee. John will probably make the Olympic team.

strong

Your cactus will surely die. 2 You're keeping it inside your shower, with no natual light, 3 but cacti need to be in a fairly dry and bright environment to thrive.

2 and 3 arrows down to 1 separately

1 Watching watching television while studying negatively affects your ability to learn: 2 television distracts your mind, and 3 distractions reduce your ability to focus.

2 and 3 joined and arrow down to 1

1 The medicine you're taking will have no effect on your illness. That's because 2 antibiotics have no effect on viruses, and 3 you have an illness that is caused by a virus, and 4 the medicine you are taking is an antibiotic.

2, 3, 4 joined and arrow down to 1

All rectangles are squares. All rectangles are parallelograms. Therefore, all parallelograms are squares. Reference: Ref 1-11 Which one of the following correctly expresses the form of the argument? (Let R = rectangles, S = squares, and P = parallelograms.)

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

No squares are triangles. No squares are circles. Therefore, no triangles are circles. Reference: Ref 1-10 Which one of the following correctly expresses the form of the argument? (Let S = squares, T = triangles, and C = circles.)

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

All rectangles are squares. All rectangles are parallelograms. Therefore, all parallelograms are squares. Reference: Ref 1-11 Which one of the following substitutions shows the argument invalid?

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

No squares are triangles. No squares are circles. Therefore, no triangles are circles. Reference: Ref 1-10 Which one of the following substitutions shows the argument invalid?

S = motorcycles, T = cats, and C = mammals.

In a valid arguments, what can NEVER occur?

all the premises are true while the conclusion is false

More damage was done last year from hurricanes than earthquakes. There was $100 million damage last year from hurricanes. There was $70 million damage last year from earthquakes.

argument

There is no reason why anyone should remain ignorant of what's going on in the world: Newspapers are a good source of in-depth news and they are easily accessible. Weekly magazines are good source of in-depth news and they are easily accessible. PBS, CNN, and CSPAN are good sources of in-depth news and they are easily accessible.

argument

I have a headache. I just took two aspirins. So, my headache will be relieved.

aspirin relieves headaches

Paris is called the "City of Lights." Las Vegas is also called the "City of Lights." So, there must be at least two cities with the same nickname. /// There must be at least two cities with the same nickname.

conclusion

We should stop interfering in other countries' affairs. This follows from the fact that we have no moral right to change a country's way of governing itself. Also, interfering often gets us locked into combat; not to mention that the potential for loss of lives on both sides is high. In addition, the cost of waging wars is astronomical. Any engagement means weakening our already shaky economy. Add the fact that interfering makes us have more enemies around the world who feel threatened by us. /// We should stop interfering in other countries' affairs.

conclusion

Every horse can run a mile in under 3 minutes. Evie has a horse. Therefore, Evie's horse can run a mile in under three minutes.

deductive

Every horse can run a mile in under 3 minutes. Evie has a pet that can run a mile in under 3 minutes. Therefore, Evie's pet is certainly a horse.

deductive

The exam's range of C scores is 70-79. I got a 98 on the exam. Therefore, I did not get a C on the exam.

deductive

A counterexample to an argument is evidence that the conclusion is false.

false

A valid argument always has a true conclusion.

false

Paris is called the "City of Lights." Las Vegas is also called the "City of Lights." So, there must be at least two cities with the same nickname. /// Paris is called the "City of Lights."

premise

We should stop interfering in other countries' affairs. This follows from the fact that we have no moral right to change a country's way of governing itself. Also, interfering often gets us locked into combat; not to mention that the potential for loss of lives on both sides is high. In addition, the cost of waging wars is astronomical. Any engagement means weakening our already shaky economy. Add the fact that interfering makes us have more enemies around the world who feel threatened by us. /// The potential for loss of lives on both sides is high.

premise

1 Anyone over 21 years of age can legally play the slot machines in Las Vegas. So, 2 Sam can legally play the slot machines in Las Vegas, because 3 Sam is 88 years old.

1 and 3 joined and arrow down to 2

1 Most Doberman dogs bark a lot. 2 Therefore, my cousin's Doberman dog will probably bark a lot, 3 since my cousin has a Doberman.

1 and 3 joined and arrow down to 2

1 For the last 10 years the best picture Oscar has gone to a drama. 2 A comedy has no chance of winning the Oscar for best picture this year.

1 arrow down to 2

1 She doesn't eat pork, 2 chicken, 3 beef, 4 mutton, 5 veal, 6 venison, 7 turkey, or 8 fish. 9 It follows that she must be a vegetarian.

1, 2, 3, 4, 5, 6, 7, 8 joined together and arrow down to 9