Critical Reasoning

The premise is the claim or claims that provide support or reasons to accept the conclusion.. To make an argument, you must articulate at least two claims, and at least one of the claims

The term critical reasoning describes a set of analytical skills that enable people to make effective arguments

and evaluate arguments made by others Sometimes critical reasoning is merely a matter of common sense.For example, if there is a hurricane outside, but I say it’s a good day to go for a walk and get some fresh air,you know something is wrong with my argument But written and spoken arguments are often much morecomplicated, and the ability to think critically and judge the effectiveness of an argument is not only impor-tant to your success on the GMAT® exam—it’s also critical to your success in the business world This sec-tion reviews the basic structure of arguments and guidelines for evaluating arguments, especially argumentslike the ones you will encounter on the GMAT exam

 E l e m e n t s o f a n A r g u m e n t

Although arguments often end up in heated debate, you don’t need to shout or elevate your blood pressure

to have an argument In fact, you don’t even need another person to argue with In the realm of critical

reasoning, an argument is a set of claims with a premise(s) and a conclusion A claim is a statement (as

opposed to a question or interjection) with a truth value—it is either true or false (although you may not

know which) The conclusion of the argument is its main claim—what the arguer wants us to see, do, or

Critical Reasoning

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Argument = Conclusion (main claim) + Premise(s) (supporting claim[s])

believe The premise is the claim or claims that provide support or reasons to accept the conclusion To make

an argument, you must articulate at least two claims, and at least one of the claims must offer (or attempt tooffer) support for the conclusion

Here are some examples The conclusion of each argument is underlined:

I do not see Xiomara anywhere She must not have arrived yet.

You should spend ten minutes each day doing yoga Deep breathing and stretching will improve your health and mood, and they are easy to fit into your day.

A flat tax is the answer to our tax troubles It would treat everyone fairly and would dramatically plify the tax code This would make filing taxes easier and make many Americans feel better about giv- ing their money to the government.

sim-Notice that this last argument offers several premises to support its conclusion:

1 A flat tax would treat everyone fairly.

2 A flat tax would simplify the tax code.

3 A flat tax (because it would simplify the tax code) would make filing taxes easier.

4 A flat tax (because it would treat everyone fairly) would make Americans feel better about paying taxes.

Of course, the more reasonable the premises and the more premises offered, the more convincing andeffective the argument You will see an example of this in a moment

It will often be clear which of the claims in an argument is the conclusion, but many times you will need

to consider the argument carefully to determine the main claim The following conclusion and premise cators can help

 C o m p l i c a t i n g A r g u m e n t s

The previous examples of arguments are quite simple, and many arguments—including many of those youwill encounter on the GMAT exam—are far more complex Within arguments, you will often find two fac-tors that complicate arguments:

1 The conclusion of one argument serves as the premise for another.

2 The conclusion and/or one or more premises are unstated.

The conclusion of one argument serves as the premise for another Like essays, arguments are often

richly layered For example, look at the following argument:

You should present our position to the board The board members trust you because they have known you for years, and you know our position better than anyone.

The claim the board members trust you actually serves as both the premise for the conclusion you should

present to the board and the conclusion for a second argument: The board members trust you (conclusion)

because they have known you for years (premise) This might be represented as follows:

conclusion ➝ premise/(becomes) conclusion ➝ premise

Sometimes this argument construction will be easy to detect; other times quickly mapping out the ment can help To do this, put brackets [] around each claim (remember that each sentence can have morethan one claim) Then determine which of those claims is the main claim—the overall point of the argument.Just as an essay may have many main ideas (a main idea for each paragraph), it also has an overall main idea.Similarly, an argument can have many different conclusions that are part of a larger argument, and the argu-ment should have one main claim (the overall conclusion) Label this main claim C1 (conclusion 1) Thenlook carefully at the premises Do they directly support C1? If so, label them P1 (premises that support C1).But if they do not directly support C1, then you might have a secondary (or tertiary, etc.) conclusion For

argu-example, they have known you for years doesn’t directly support the claim you should present our position to

the board Thus, you need to find the claim it does directly support (the board members trust you) and label

that claim C2 Thus, the claim the board members trust you is labeled both P1 and C2, and they have known

you for years is labeled P2 (premise supporting C2) Meanwhile, you know our position better than anyone

directly supports C1, so it is labeled P1:

Here is another example:

P3[With more and more classes being offered online, more and more students will soon earn their degrees

P3

in virtual universities.] [Already, students in California are graduating from schools in New York without ever

P2/C3leaving their state.] Because [online courses offer flexibility without geographic boundaries],

[virtual degrees will be in ever greater demand], and [colleges and universities should invest the bulk of theirresources in developing online degree programs.]

In this argument, the final claim is the overall conclusion, the main claim of the argument

Identifying the main claim (which we will refer to simply as the conclusion for the rest of this section)

is a critical skill on the GMAT exam You must be able to identify the conclusion to effectively evaluate anargument, and you need to be able to see when the conclusion is in fact missing from an argument This isthe second complication:

The premise and/or conclusion of an argument is unstated These arguments are common both in real

life and on the GMAT exam The problem with an argument that contains unstated premises and conclusions

is that it leaves room for the premise or conclusion to be misunderstood For example,

You should turn her in for cheating She violated the honor code.

This argument has an unstated premise—a key idea that links the conclusion and premise together In

order for this argument to be clear and strong, you need to know the unstated assumption that makes thisargument possible:

People who violate the honor code should be turned in.

This could be stated in a slightly different way, but the assumption behind this argument is now clear.This is crucial because unless you understand all of the premises upon which an argument is based, you can-not effectively evaluate that argument and determine whether or not it is valid

Here is another example of an argument with an unstated premise:

We should offer online classes because other schools are now offering online classes.

At first glance, this might seem like a simple case of poor logic, an “everyone else is doing it” approach.But if you recognize the unstated assumption, then this is a much stronger argument:

We need to do what other schools are doing to stay competitive.

Finding an Unstated Premise

When you are presented with an argument that has an unstated premise, you need to determine what claimwould link the existing premise and conclusion together What must be true (assumed) in order for the con-clusion to be true? This missing premise is a necessary transition or bridge between the premise andconclusion, one that probably makes the conclusion true For example, look at the following argument:

[Ellen plagiarized.] [She should be punished.]

An argument that jumps from premise to conclusion like this is called a non sequitur (jumping to

con-clusions) This can be corrected by stating the premise that links the conclusion and premise:

[Ellen plagiarized.] [Plagiarism is wrong.] [Therefore, she should be punished.]

Here is another example Notice how the unstated premise links the premise to the conclusion in thesecond version:

I promised to clean the garage on Saturday I better clean the garage on Saturday (non sequitur)

I promised to clean the garage on Saturday People should keep their promises I better clean the garage on Saturday (logical, complete argument)

Not every argument with an unstated premise is a non sequitur, but you should follow essentially thesame process to determine and evaluate unstated assumptions Take another look at question 8 from the

pretest, for example This question asks you to determine which assumption the conclusion is not based upon:

8 Morning Glory, the coffee shop on the corner, has lost nearly 50% of its business because a national

retail coffee chain opened up a store down the street Instead of closing up shop, the owner of ing Glory plans to draw in customers by offering coffee, tea, and pastries at much lower prices than thenational coffee chain

Morn-The owner’s plan of action is based on all of the following assumptions EXCEPT

a some customers will choose the coffee shop that offers the lowest price.

b the quality of Morning Glory’s coffee is comparable to that of the national coffee chain.

c Morning Glory can afford to cut its profit margin in order to lower prices.

d Morning Glory’s customers are very loyal.

e the national coffee chain will not lower its prices in order to compete with Morning Glory.

The first step to tackling this question is to clearly identify the core argument This plan of action could

be reworded as follows:

[Its prices will be lower than the national coffee chain’s], so [Morning Glory will stay in business]

Now, this argument has several unstated assumptions To answer the question, you need to identify

which one is not a logical connection between the premise and the conclusion You can simply insert each

choice between the premise and conclusion to see if it forms a logical link:

P P[Its prices will be lower than the national coffee chain’s] and [ ] so

C[Morning Glory will stay in business]

Broken down in this manner, it should be easy to see that all of the assumptions except d form a

logi-cal link between premise and conclusion If customers are loyal, they will continue to patronize MorningGlory, whether or not their prices are lower This is the only assumption that does not fit the argument

Determining an Unstated Conclusion

Determining the unstated conclusion of an argument is like finding an implied main idea In a reading sage, you would ask the following questions: What overall impression do the examples and ideas in the textadd up to? What idea or concept do the ideas from the text support? Similarly, in critical reasoning, you mustask the following questions:

pas-■ What do these premises add up to?

■ What idea or claim does this evidence amount to?

■ If these premises are true, what else then is also likely to be true?

For example, look at the following passage:

Rajita paid $35 for her scarf at Hanson’s on sale The same scarf is $20 (regular price) at Lambert’sand only $18 (regular price) at Sam’s

Which one of the following conclusions can be logically drawn from the passage?

a Rajita does not know where to shop.

b There is no Sam’s or Lambert’s in Rajita’s area.

c You will probably pay more for most items at Hanson’s than at Lambert’s or Sam’s.

d Sam’s sale prices are always the best.

e Rajita bought the scarf at Hanson’s because she was already there buying other things.

All of these choices could be true, but only one is likely to be true based on the evidence in the passage.

Maybe Rajita doesn’t know where to shop (choice a); maybe she has no idea that Lambert’s and Sam’s have

the same merchandise at better prices But there is no evidence of this in the passage The same is true of

choices b, d, and e; they may be true, but there is no evidence in the passage (We know Sam’s regular price

for the scarf is the best, but we don’t know if Sam’s sale prices are always better than Lambert’s.) Only choice

c is a logical conclusion based on the passage If Hanson’s sale price is $35, nearly twice the price for the same

merchandise from Sam’s, you will probably pay more for most items at Hanson’s

On the exam, you will also see questions where several conclusions can be drawn from a series of

prem-ises, and you must determine which of the conclusions presented is not logical based on the evidence

(prem-ises) provided This was the case with question 9 from the pretest:

9 When romance novels were located in the back of the bookstore, they accounted for approximately 6%

of total sales Since we moved romance novels close to the front of the store and put several books ondisplay, sales of romance novels have increased to 14% to 18% of total sales

All of the following conclusions can logically be drawn from this argument EXCEPT

a customers who bought one romance novel are likely to come back for another.

b customers are more likely to buy books located near the front of the bookstore than at the back.

c the display caught the interest of people who might not have otherwise purchased a romance novel.

d customers believe that bookstores put their best books near the front of the store.

e sales of romance novels may increase even more if the section were moved all the way to the front.

To answer this question correctly, you must evaluate each option in light of the evidence In this case,

the only conclusion that does not logically follow from the premises is a The significant increase in sales after

the relocation of the books indicates that customers are more likely to buy books at the front of the store

(choice b) and that the display may have caught the interest of people who might not otherwise purchase a romance novel (choice c) It is also logical to conclude that sales would further increase if the books were moved even farther toward the front of the store (choice e) Choices b and e and the increase in sales all sug- gest that customers believe the best books are near the front of the store (choice d) The only conclusion that

cannot logically be drawn from this scenario is that customers will come back to purchase more romance

nov-els (choice a) There is no evidence here for this conclusion; nothing in the data indicates repeat purchases

for customers

 E v a l u a t i n g A r g u m e n t s

Many GMAT critical reasoning questions will ask you to evaluate an argument This usually means you will

have to assess the logic of the argument and/or the effectiveness of the evidence provided in support of theconclusion To do this, you need to consider three elements of effective arguments:

■ Qualifiers Does the argument allow for exceptions, or make an absolute claim?

■ Evidence Does the argument provide strong evidence to accept the claim?

■ Logic Does the argument present reasonable premises, or is it based on faulty logic?

Qualifiers are words and phrases that limit the scope of a claim to help make an argument more valid (more

likely to be true) For example, take a look at the following arguments:

1 Don’t believe anything politicians say All politicians are corrupt.

2 Don’t believe most of what politicians say Most politicians are corrupt.

3 Be careful believing what politicians say A lot of politicians are corrupt.

Which argument is the strongest? Although argument 1 is the most assertive, it’s also the weakest ment It is the least likely to be true because it uses absolute terms (anything and all) in both its conclusion and premise Argument 2 is much stronger because it uses the word most to qualify its conclusion and prem-

argu-ise But it is still telling you to disbelieve most of what politicians say, and even the most corrupt politiciansprobably don’t lie most of the time It still asserts that most politicians are corrupt, a claim that will likely bedifficult to prove Argument 3 may seem the weakest because of its qualifiers, but it is actually the strongestbecause it is the most plausible argument of the three It is the most likely to be true

The following words and phrases can significantly strengthen arguments by qualifying them:

argu-With this knowledge, it should be easier to answer a question such as the following:

I should not bother getting Hal a birthday gift this year He is never happy with anything he gets fromanybody

Which of the following statements would most strengthen the speaker’s argument?

a Hal is simply impossible to please.

b At least he is never been happy with a gift from me, and I have tried just about everything.

c Besides, Hal does not need anything—he already has everything he wants.

d Hal is disgusted with our consumption-obsessed culture.

e Hal even complains about gift certificates.

The best choice is b, the only statement that offers qualifiers to make the argument more likely to be true (and therefore stronger) In b, the speaker limits Hal’s discontent with gifts to the gifts given by the

speaker The speaker also says she has tried just about everything, a qualifier that allows for the possibility that

she simply has not been able to find the right gift Thus, choice b actually strengthens the argument.

Evidence

A good argument will provide strong evidence of its conclusion This means that there is sufficient evidence

(this often means more than just one premise) and that the evidence provided in support of the conclusion

is strong (reasonable and convincing).

Many types of evidence can be provided, including the following:

Evaluating Evidence

When you are presented with evidence in argument, you should ask several important questions:

■ Is there sufficient evidence to accept the conclusion?

■ Is the evidence relevant to the conclusion?

■ Does the evidence come from an unbiased source?

■ Is the evidence logical?

The more that is at stake in the conclusion (the more controversial it is, the more risk you take in acceptingthe argument), the more evidence you should have before accepting the claim

For example, in the DNA argument from the pretest, which we will return to in a moment, the stakesare very high—the conclusion asks us to agree that thousands of convictions should be reviewed and poten-tially overturned on the likelihood that many innocent people are serving time in prison This is a serious mat-ter, so the amount of evidence should be plentiful.

For example, if you are arguing that colleges and universities should offer more classes online, the followingevidence might be compelling, but it is not relevant:

At one campus, 68% of students said they spent an average of two to three hours online each day.

The following item of evidence, however, is relevant:

According to a survey of students at three large state universities, 72% of students stated that they would

be “very interested” in taking courses online.

Bias is a strong inclination or preference for one person, position, or point of view over others As discussed

earlier, surveys can be loaded so that the answers will favor particular responses; similarly, experts may not

be objective because they have something to gain from espousing a particular point of view You need to sider the potential bias of a source when you consider evidence in an argument For example, take a politi-cal science professor who is asked to evaluate a candidate for a local election Many factors can bias theprofessor’s assessment of the candidate’s merits, including whether or not the professor has any personal orprofessional relationship with the candidate; whether or not they have had past experiences with each otherand of what sort; whether or not they belong to the same political party; and whether or not any potentialrewards might befall the professor should the candidate win The following question addresses this kind ofproblem:

con-City Treasurer: Vote Carson for Governor Carson knows what it takes to turn the state’s economyaround He will create jobs and improve education Carson knows how to get things done

Which of the following provides the best reason to reject the treasurer’s argument?

a The treasurer belongs to the same political party as Carson.

b The treasurer has known Carson for less than one year.

c The treasurer once lost an election against Carson.

d The treasurer has been promised a position in Carson’s cabinet if he wins.

e The last candidate the treasurer backed lost the election.

Choice d indicates that the treasurer has a real stake in Carson’s winning the election; if Carson wins,

he will be on the governor’s payroll Maybe he does believe that Carson can turn the state around, but becausehis potential for bias is so high, voters would be wise not to let this politician influence their feelings aboutCarson and seek other evidence that Carson would (or would not) be a good governor

Sources are credible if they:

• have expertise in the subject matter (based upon their experience, education, reputation, recognition, andachievements)

• are free from bias

I S THE E VIDENCE L OGICAL ?

Logical means reasonable, based on good common sense, not emotional It is logical, for example, to conclude

that if it is snowing outside, it is cold It is not logical to assume that it will stop snowing if you wish for it hard enough It is logical to argue that you should exercise because it will make you feel better—logic does not discount emotions—but it is not logical to argue that you should not help your brother because you are angry with him Feeling better about yourself is a good reason to exercise; you are doing something in order

to feel a positive and healthy emotion Not helping your brother because you are angry, however, is not ical You need to provide logical reasons for whether or not you should help your brother Not helping yourbrother because the last two times you helped him he broke your glasses in half is logical!

log-Logical Fallacies

Logical fallacies are errors in reasoning that all too often find their way into arguments Dozens of fallaciesexist, but the ones you are most likely to encounter on the GMAT exam are also the ones you are most likely

to encounter in everyday life:

■ comparing apples to oranges

Jonas has an apple in one hand and an orange in the other “Look how much redder the apple is than theorange,” he says “And the orange is so much more orange.”