PHL202 Exam 2

A _________ __________ asserts or denies that something is the cause of something else. Here are examples: -I can't log on. The network must be down. -Rashid isn't allergic to peanuts. I saw him eat a bag of peanuts on the flight from Dallas.

Causal Argument

______ _________ consist of three conditional statements that link together in the following way: -If A then B -If B then C -Therefore, if A then C Here is an example of a _______ _______: -If we don't stop for gas soon, then we'll run out of gas -If we run out of gas, then we'll be late for the wedding -Therefore, if we don't stop for gas soon, we'll be late for the wedding ________ ________ arguments have the following pattern: -If A then B -Not B -Therefore, not A Arguments of this pattern are sometimes called "________ the __________."

Chain arguments chain argument Modus tollens denying the consequent

____________ arguments claim to provide logically conclusive grounds for their conclusions. That is, they attempt to show that their conclusions must be true given the premises asserted. _________ arguments, on the other hand, simply claim that their conclusions are likely or probable given the premises offered.

Deductive Inductive

_________ __________ try to prove their conclusions with rigorous, inescapable logic. ___________ _________ try to show that their conclusions are plausible or likely given the premise(s).

Deductive Arguments Inductive Arguments

___________ the _________ arguments have the following pattern: -If A then B -Not A -Therefore, not B Here is an example: -If Shakespeare wrote War and Peace, then he's a great writer -Shakespeare didn't write War and Peace -Therefore, Shakespeare is not a great writer Another faulty pattern of deductive reasoning is ________ the ____________. Its pattern is as follows: -If A then B -B -Therefore, A Here is an example: -If we're on Neptune, then we're in the solar system -We are in the solar system -Therefore, we're on Neptune

Denying the antecedent affirming the consequent

Inductive arguments always move from particular premises to a general conclusion. (T/F)

False

No valid argument has a false premise. (T/F)

False

"Probably," "likely," and "it's a good bet that" are common induction indicator words. (T/F)

True

No cogent argument has a false premise. (T/F)

True

Statistical arguments are generally inductive arguments. (T/F)

True

________ means that the argument is well reasoned, that the pattern of reasoning is a logically reliable pattern of reasoning, that the conclusion follows necessarily from the premises.

Valid

An _______ is a comparison of two or more things that are claimed to be alike in some relevant aspect. In an ____________ from __________, the conclusion is claimed to depend on an ________ between two or more things. -Hershey Park has a thrilling roller-coaster ride -Dorney Park, like Hershey Park, is a great amusement park -Therefore, probably Dorney Park also has a thrilling roller-coaster ride

analogy argument from analogy analogy

In an ____________ _________ on ___________, the conclusion is claimed to depend largely or entirely on some mathematical calculation or measurement (perhaps in conjunction with one or more nonmathematical premises). Here are two examples: -Eight is greater than four -Four is greater than two -Therefore, eight is greater than two

argument based on mathematics

Which of the following is not a common pattern of deductive reasoning:

argument by analogy

An _______ by ______ seeks to logically rule out various possibilities until only a single possibility remains. Here are two examples: -Either Joe walked to the library or he drove. -But Joe didn't drive to the library -Therefore, Joe walked to the library

argument by elimination

An ____________ from ___________ asserts a claim and then supports that claim by citing some presumed authority or witness who has said that the claim is true. Here is an example: -More Americans die of skin cancer each year than die in car accidents. How do I know? My doctor told me.

argument from authority

In an _________ from _________, the conclusion is presented as being "true by definition," that is, as following simply by definition from some key word or phrase used in the argument. Here are two examples: -Janelle is a cardiologist. Therefore, Janelle is a doctor. -Bertha is an aunt. It follows that she is a woman.

argument from definition

Another common pattern of deductive reasoning is ________ _________. For present purposes, a __________ __________ may be defined as a three-line argument in which each statement begins with the world all, some, or no. Here are two examples: -All oaks are trees -All trees are plants -So, all oaks are plants

categorical syllogism categorical syllogism

Other common varieties of hypothetical syllogisms include: -_______ _______ -_______ __________ (denying the consequent) -_________ the __________ -________ the __________

chain argument modus tollens denying the antecedent affirming the consequent

If an argument both is inductively strong and has all true premises, it is said to be a _________ argument. If an inductive argument is weak or has at least one false premise, it is an __________ argument.

cogent uncogent

Because deductive and inductive arguments often occur in characteristic, telltale patterns of reasoning, we can apply the _______ _________ test to determine which kind of reasoning we are dealing with. Consider this argument: -If we're in Paris, then we are in France -We are in Paris -Therefore, we are in France This argument has a particular pattern or form that occurs frequently in deductive reasoning. The general pattern of the argument is this: -If [the first statement] is true, then [the second statement] is true -[The first statement] is true -Therefore, [the second statement] is true -If A then B -A -Therefore, B This is an argument pattern that logicians call __________ _________, a Latin expression that means "affirmative mode." Because it is obvious that this is a logically reliable pattern of reasoning, arguments of this pattern should always be treated as deductive.

common pattern modus ponens

Here are some common ________ ________ words: -certainly -definitely -absolutely -conclusively -it logically follows that -it is logical to conclude that -this logically implies that -this entails that These are some common _______ ______ words: -probably -likely -it is plausible to support that -it is reasonable to assume that -one would expect that -it is a good bet that -chances are that -

deduction indicator induction indicator

All __________ arguments claim, explicitly or implicitly, that their conclusions follow necessarily from their premises.

deductive

Here are two examples of _______ arguments: -All humans are mortal -Socrates is human -Therefore, Socrates is mortal -If the president lives in the White house, then he lives in Washington, D.C. -The president does live in the White House -So, the president lives in Washington, D.C.

deductive

Two patterns that are not logically reliable are _________ the _________ and _______ the _________.

denying the antecedent and affirming the consequent

No sound argument has

false premises

A _________, as that term is used in critical thinking, is a statement that attributes some characteristic to all or most members of a given class.

generalization

Which of the following is not a common pattern of inductive reasoning:

hypothetical syllogism

Five common patterns of deductive reasoning: -_______ _______ -______ ________ -______ by _______ -_______ based on __________ -________ from __________

hypothetical syllogism categorical syllogism argument by elimination argument based on mathematics argument from definition

There are four tests that greatly simplify the task of determining whether an argument should be regarded as deductive or inductive: -The _______ ______ test -The ______ ________ test -The _______ _________ test -The _________ of ________ test

indicator word strict necessity common pattern principle of charity

Here are some examples of ________ arguments: -Polls show that 75 percent of Republicans favor a school prayer amendment -Joe is a Republican -Therefore, Joe likely favors a school prayer amendment -Every ruby so far discovered has been red -So, probably all rubies are red -The bank safe was robbed last night -Whoever robbed the safe knew the safe's combination -Only two people know the safe's combination: Lefty and Bugsy -Bugsy needed money to pay his gambling debts -Bugsy was seen sneaking around outside the bank last night -It is reasonable to conclude, therefore, that Bugsy robbed the safe

inductive

The argument "Every previous U.S. president has been a man, so, it's likely that the next U.S. president will be a man." is

inductive

An ___________ ________ is an argument in which a generalization is claimed to be probably true based on information about some members of a particular class. Here are two examples: -All dinosaur bones so far discovered have been more than sixty-five million years old. -Therefore, probably all dinosaur bones are more than sixty-five million years old.

inductive generalization

Six common patterns of inductive reasoning: -________ _________ -______ ________ -______ from ________ -______ __________ -__________ __________ -_________ from __________

inductive generalization predictive argument argument from authority causal argument statistical argument argument from analogy

The principle of charity is a principle of ___________, not a principle of _______ ________.

interpretation argument repair

Exceptions to the Strict Necessity Test An argument in which the conclusion does not follow necessarily from the premises should nonetheless be treated as deductive if either: 1. The ________ or ________ makes clear that the arguer intended to offer a logically conclusive argument, but the argument, in fact, is not logically conclusive or 2. the argument has a _________ of __________ that is characteristically deductive, and nothing else about the argument indicates clearly that the argument is meant to be inductive

language or context pattern of reasoning

A _________ is a statement about what may or will happen in the future. In a _________ ________, a prediction is defended with reasons. Predictive arguments are among the most common patterns of inductive reasoning. Here are two examples: -It has rained in Vancouver every February since weather records have been kept. -Therefore, it will probably rain in Vancouver next February.

prediction predictive argument

In evaluating any argument, one should always ask two key questions: (1) Are the __________ true? and (2) Do the ________ provide good reasons to accept the conclusion?

premises premises

The ___________ of __________ should never be used to reinterpret bad arguments as good ones.

principle of charity

Deductive arguments that are both valid and have all true premises are called _____ _______ arguments. Deductive arguments that either are invalid or have at least one false premise, or both, are called ________ ________ argument.

sound deductive unsound deductive

A ________ _______ rests on statistical evidence--that is, evidence that some percentage of some group or class has some particular characteristic. Here is an example: -Eighty-three percent of St. Stephen's students are Episcopalian -Beatrice is a St. Stephen's student -So, Beatrice is probably Episcopalian

statistical argument

The _______ _______ test can be stated as follows: An argument's conclusion either follows with strict logical necessity from its premises or it does not If the argument's conclusion does follow with strict logical necessity from its premises, the argument should always be treated as deductive. If the argument's conclusion does not follow with strict logical necessity from its premises, the argument should normally be treated as inductive.

strict necessity

Inductive arguments, like deductive arguments, can be well reasoned or poorly reasoned. A well-reasoned inductive argument is called a strong inductive argument. More precisely, in a _____ _______ argument, the conclusion follows probably from the premises. Put otherwise, a strong inductive argument is an argument in which the following conditions apply: -If the premises are true, the conclusion is probably true -The premises provide probably, but not logically conclusive, grounds for the truth of the conclusion -The premises, if true, make the conclusion likely

strong inductive

Inductive arguments can be either

strong or weak

A ____________ is a three-line argument, that is, an argument that consists of exactly two premises and a conclusion. A _________ _________ is a _________ that contains at least one hypothetical or conditional (if-then) premise. Here are two examples of ________ _______: -If the Tigers beat the Yankees, then the Tigers will make the playoffs -The Tigers will beat the Yankees -So, the Tigers will make the playoffs -If I want to keep my financial aid, I'd better study hard -I do want to keep my financial aid -Therefore, I'd better study hard

syllogism hypothetical syllogism syllogism hypothetical syllogisms

An invalid argument can have any combination of truth or falsity in the premises or conclusion. A valid argument can have any combination except one: No valid argument can have _____ premises and a ______ conclusion.

true false

As with valid deductive arguments, however, there is one combination of truth or falsity no strong inductive argument can ever have. Because, by definition, a strong inductive argument is an argument in which the conclusion follows probably from the premises, no strong inductive argument can have ______ premises and a probably _______ conclusion.

true false

It is not necessary to know whether an argument's premises or conclusions are ________ to know whether an argument is valid. In fact, some valid arguments have obviously ________ premises and ________ conclusion: For example: -All squares are circles -All circles are triangles -Therefore, all squares are triangles

true false false

No valid argument can have all _____ premises and a ______ conclusion. A deductive argument in which the conclusion does not follow necessarily from the premises is said to be an _________ ____________ argument. For example: -All dogs are animals -Lassie is an animal -Therefore, Lassie is a dog

true false invalid deductive

All deductive arguments are either 100 percent ________ or 100 percent _______.

valid invalid

A _________ ________ argument is an argument in which it is impossible for all the premises to be true and the conclusion false. Put another way, a _______ _________ argument (or _______ _______ for short) is an argument in which these conditions apply: -If the premises are true, the conclusion must be true -The conclusion follows necessarily from the premises -The premises provide logically conclusive grounds for the truth of the conclusion -It is logically inconsistent to assert all the premises as true and deny the conclusion

valid deductive valid deductive valid argument

In a ______ ________ argument, the conclusion does not follow probably from the premises. In other words, a weak argument is an inductive argument in which the premises, even if they are assumed to be true, do not make the conclusions probable.

weak inductive