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2 Elements of Reasoning Well

Added By: Jamie Morgan

July 11, 2019

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Reasoning Well is Critical for Effective Decision Making

There is much truth to the old saying that life is just one decision after another.

That’s why decision-making is one of life’s major preoccupations.

“Reasoning well” is an essential ingredient in decision-making.

The trick, of course, is to reason well.

This lesson is about good reasoning, about how to reason well in everyday life whether dealing with personal decisions or those of a social or political nature.

All of us like to think of ourselves as rational human beings, yet most of what we know is passed on to us by other people.

We know, for instance, that the earth is round because we’ve been told it is, even though our intuition is that it is flat because we walk on flat surfaces every day. In fact, for centuries, nearly everyone believed it was flat until scientific evidence proved without question that it isn’t.

Much of what we think we know is based on beliefs, sometimes unsupported by accurate information, instilled in us from childhood on. And too often, beliefs collapse into gut reactions to all manner of issues from gun control to same-sex marriage to legalizing drugs. A gut reaction is not the same as rational thought, however, nor is a belief, unless it has been examined for accuracy against conflicting ideas and evidence.

Reasoning well requires information, as well as the ability to process that information well.

Fortunately, “no man is an island.”

We all have available to us a lot of knowledge others have gained through experience and good reasoning, accurate information, and well-intended advice available to anyone who reaches out for it.

Unfortunately, not all information is created equal.

Charlatans and fools can speak as loudly as saints or geniuses. Self-interest often clouds the thinking of even the brightest individuals.

The trick when evaluating the mountain of verbiage we all are exposed to is to separate the nourishing wheat from the expendable chaff.

One way to become good at doing this is to think a bit about what makes reasoning good (cogent), as opposed to bad (fallacious).

1. Reasoning and Arguments

Here is a simple example of reasoning about the nature/nurture issue:

Identical twins often have different IQ test scores. Yet these twins inherit exactly the same genes. So the environment must play some part in determining a person’s IQ.

Logicians call this kind of reasoning an argument. In this case, the argument consists of three statements:

1. Identical twins often have different IQ test scores.

2. Identical twins inherit the same genes.

So, 3. environment must play some part in determining IQ.

The first two statements in this argument give reasons for accepting the third. In logic terms, they are said to be premises of the argument. And the third statement, which asserts the claim for which the premises offer support, is called the argument’s conclusion.

In everyday life, few of us bother to label premises or conclusions. We usually don’t even bother to distinguish one argument from another. But we do sometimes give clues called logical indicators. Words such as because, since, and for, usually indicate that what follows is a premise of an argument. Therefore, thus, consequently, and so generally signal conclusions. Similarly, expressions such as “It has been observed that . . . ,” “In support of this … ,” and “The relevant data are .. .” are used to introduce premises, while expressions such as “The point of all of this is . . . ,” “The implication is… ,” and “It follows that …” are used to signal conclusions.

Here is a simple example:

Since it’s always wrong to kill a human being [premise], it follows that capital punishment is wrong [conclusion], because capital punishment takes the life of [kills] a human being [premise].

Put into Standard form, the argument looks like this:

1. It’s always wrong to kill a human being.

2. Capital punishment takes the life of (kills) a human being.

:.3. Capital punishment is wrong. (The symbol :. often is used as shorthand for the word therefore and thus indicates that a conclusion follows.)

In this form, we display only the premises and conclusion of the argument. We leave out logical indicators since the logical structure of the argument is shown by the way we arrange the sentences. Of course, an argument may have any number of premises and may be surrounded by or embedded in other arguments or extraneous material.

In addition to using logical indicators such as since, because, and therefore, we sometimes employ sentence order-the last sentence in a series stating an argument’s conclusion-and occasionally even express a conclusion in the form of a question.

Consider this section of President Obama’s 2016 State of the Union address:

Our unique strengths as a nation, our optimism and work ethic, our spirit of discovery, our diversity, our commitment to rule of law-these things give us everything we need to ensure prosperity and security for generations to come. In fact, it’s that spirit that made the progress of these past 7 years possible. It’s how we recovered from the worst economic crisis in generations. It’s how we reformed our health care system, and reinvented our energy sector; how we delivered more care and benefits to our troops and veterans; and how we secured the freedom in every state to marry the person we love. But such progress is not inevitable. It’s the result of choices we make together. And we face such choices right now. Will we respond to the changes of our time with fear, turning inward as a nation, turning against each other as a people? Or will we face the future with confidence in who we are, in what we stand for, in the incredible things that we can do together?

The rhetorical questions at the end invite us to respond that we should face the future with confidence instead of fear. In the preceding paragraphs, Obama gave reasons for this conclusion (and, of course, touted his administration’s accomplishments while he was at it).

We should also note that, in daily life, premises and even the conclusions of arguments sometimes are implied rather than stated outright.

Life is short, and we don’t always bother to spell out matters that are obvious or not at issue or can be taken for granted. In the IQ example given earlier, for instance, the premise that IQ differences must be due either to genetics or to environmental factors was omitted as generally understood. When assessing arguments, we should, by all means, add unstated premises of this kind when they are relevant.

Sometimes people leave conclusions unstated as a kind of rhetorical device. We often feel more committed to beliefs we come to on our own, and leaving conclusions unstated can give us the impression that we’ve done just that.

In a debate in Wisconsin during the 2016 presidential primary campaign season, Hillary Clinton had this to say about her opponent Bernie Sanders’s plan for funding higher education:

You know, I think, again, both of us share the goal of trying to make college affordable for all young Americans. And I have set forth a compact that would do just that for debt-free tuition.  We differ, however, on a couple of key points. One of them being that if you don’t have some agreement within the system from states and from families and from students, it’s hard to get to where we need to go.  And Senator Sanders’s plan really rests on making sure that governors like Scott Walker contribute $23 billion on the first day to make college free. I am a little skeptical about your governor actually caring enough about higher education to make any kind of commitment like that.

The unstated conclusion here is that Sanders’s plan is impractical and unlikely to succeed. It was probably neither by accident nor mistake that Clinton left this out.

Exposition and Argument

Of course, only those groups of statements that provide reasons for believing something form arguments. Thus, anecdotes are not usually arguments, nor are most other forms of exposition. But even in these cases, arguments often are implied.

Here is a sales clerk talking about the difference between the cameras on two phones, a Samsung and a Motorola. “Well, the Motorola has 21 megapixels and the Samsung has only 16. They both have terrific image quality, but Samsung has optical stabilization. The Motorola right now is $150 less, but it has fewer features.” Although the clerk’s remarks contain no explicit argument because no conclusion is stated, a conclusion is definitely implied. You should choose the Samsung if you want more camera features; otherwise, you should choose the Motorola.

The point is that talk generally is not aimless. A good deal of everyday talk, even gossip, is intended to influence the beliefs and actions of others and thus constitutes a kind of argument.

In the phone example, the clerk provided information intended to convince the customer to draw either the conclusion, “I’ll buy the Samsung because the additional features are worth the extra $150 to me,” or the conclusion, ‘Not to buy the Motorola because high-powered options aren’t worth $150 more to me.” In other words, the point of the clerk’s chatter was to sell a phone. Similarly, advertisements often just provide product information rather than advance explicit arguments, yet clearly every such ad has an implied conclusion-that you should buy the advertised product.

Nevertheless, it is important to understand the difference between rhetoric that is primarily expository and discourse that is basically argumentative. An argument makes the claim, explicit or implicit, that one of its statements follows from some of its other statements. It at least implies that acceptance of its conclusion is justified if one accepts its premises. A passage that is purely expository gives us no reason to accept any “facts” it may contain (other than the implied authority of the writer or speaker, as, for example, when a friend tells us that she had a good time at the beach).

3. Arguments vs. Explanations

One form of exposition that is especially likely to be confused for argument is the ex- planation. Explanations are often structured much like arguments and even use some of the same words to introduce them (“because,” “since,” etc.). But explanations are not

arguments. Arguments are used to persuade an audience that some claim is true. Expla- nations are used to provide an audience with greater understanding about a given claim. When we explain something, we take its truth for granted. That is to say, arguments give us reasons to believe something, while explanations give us the reasons why something is (or has come to be) the case. To put it another way, explanations answer the question “Why is that claim true?” while arguments answer the question “Why should I believe that claim is true?”

For instance, have a look at this passage from Matthew T. Hall of the San Diego Tribune on the fact that the first presidential primary election is always held in New Hampshire:

I’ve seen firsthand why New Hampshire should be first in line. Sure, the state isn’t as diverse as it could be and its winners don’t always get their party’s nom- ination, but the state’s complexion is going to change with the country’s and
its voters have shown the door to unfit candidates. Retail politics has real value there, and unsurprisingly for a state whose motto is “Live Free or Die,” it has a huge share of independent voters. Put simply, I think they value their first-in- the-nation primary status in ways people in states getting the distinction every so often would not.

And then this from “New Hampshire’s primaries have informally been the earliest since 1920, but over the years, the state has passed laws to ensure that its primaries will remain the first in the nation.”

The first quote above is part of an attempt to persuade us that New Hampshire should hold the first primary. The second is an attempt to say why New Hampshire is first. The first one is an argument, the second an explanation.

Like just about any other form of exposition, explanations can be used to make implicit arguments. Still, the distinction between arguments and explanations is impor- tant to maintain as they call for different kinds of evaluation. (Did we just argue for or explain the claim that maintaining a distinction between arguments and explanations is important?)

4. What Does “Winning an Argument” Mean?

When we talk about an argument in this context, we clearly do not mean anything like a fight, and our sense of “argument” does not even imply any disagreement. So it is not clear that it is proper to ask what it means to “win” arguments as we understand them. That said, we are interested in the ways that arguments are actually used (hence the “and Contemporary Rhetoric” part of the title) and so we should take a moment to think about what it means for an argument to be successful.

From a strictly logical perspective, the only criterion for a successful argument is the quality of the argument itself, and we will turn in the next few sections to some ways of evaluating arguments in this respect. But an argument can be logically sound and still not very persuasive. That is to say, just because an argument should be convincing does not mean that it will be.


At the same time, we should not count as successful an argument that is persuasive but illogical. A truly “winning” argument is one that is in fact persuasive because it is rational to accept its conclusion on the basis of its premises. As we’ll see throughout this text, the combination of logical integrity and rhetorical effect may be all too rare an accomplishment.

5. Cogent Reasoning

Our chief concern to this point has been the identification of arguments. We can now turn our focus to their evaluation. Reasoning can be either cogent (good) or fallacious (bad). We reason cogently when we satisfy the following conditions:

1. The premises of our reasoning are believable (warranted, justified), given what we already know or believe.

2. We consider all likely relevant information.2
3. Our reasoning is valid, or correct, which means that the premises we employ

provide good grounds for accepting the conclusion we draw.3
When any of these three conditions of cogent reasoning are not satisfied, reasoning is

said to be fallacious. BELIEVABLE PREMISES

The first condition of good argument evaluation requires that we bring to bear whatever we already know or believe-our relevant background beliefs and information-to determine whether we should or shouldn’t accept the premises of the argument in ques- tion. Take, for instance, the first premise of the capital punishment argument discussed earlier-the premise making the claim that taking the life of a human being always is wrong. Most of us are not pacifists-we don’t believe that it always is wrong to take a human life. Bringing that background belief to bear thus should make us see the first premise of the capital punishment argument as questionable. So we should not accept the conclusion of that argument unless further reasons are presented in its support. (On the other hand, those of us who are pacifists obviously should reason differently.)

By way of contrast, consider the stated premise of the following argument:

Novak Djokovic must be a terrific tennis player. He won the Wimbledon championship in 2015. (The implied premise is that anyone who wins the tournament at Wimbledon must be a terrific tennis player.)

2Satisfying this extremely stringent requirement is usually beyond the ability of most of us most of the time. The point is that good reasoners try to come as close as possible to satisfying it, taking into account the importance of drawing the right conclusion and the cost (in time, effort, or money) of obtaining or recalling relevant information . (One of the marks of genius is the ability to recognize that information is relevant when the rest of us fail to notice.)

3Provided we know nothing else relevant to the conclusion. Note that reasoning from an unjusti- fied premise may still be cogent if it also employs justified premises that sufficiently support its conclusion. Note also that the term valid sometimes is used more broadly than we have used it here.

Tennis fans know that the Wimbledon Grand Slam championship is one of the most demanding tennis competitions in the world, and acceptance of the stated premise (that Djokovic won the tournament) is warranted by plenty of background information.

It’s interesting to notice that, in effect, evaluating a premise of an argument by bring- ing background beliefs to bear entails constructing another argument whose conclusion is either that the premise in question is believable or that it isn’t. For example, when evaluating the capital punishment argument discussed before, someone who is not a pacifist might construct the following argument: “I believe that it isn’t wrong to kill in self-defense, or in wartime, or to kill those guilty of murder. So I should reject the prem- ise that taking a human life always is wrong.”

But what, you might be asking, about your own premise, that “it isn’t wrong to kill in self-defense or in wartime, or to kill those guilty of murder”? Shouldn’t that be subject to evaluation as well? This is a difficult question. We certainly should subject our own beliefs to scrutiny. But at the same time, if we evaluated every premise using another argument, including those premises used in the evaluating arguments, this process would never end! We will consider the use of background beliefs in greater detail later in this chapter. For now, let’s just say that this process of evaluation should end in prem- ises that are as self-evident as possible.

This brings to mind the fact that in daily life we often are exposed to assertions, or claims, that are not supported by reasons or arguments. Clearly, it is not rational to accept these assertions without evaluating them for believability, and, obviously, their correct evaluation requires us to do exactly what we do when evaluating the believa- bility of the premises of an argument-namely, bring to bear what we already know or believe. Evaluating unsupported assertions thus involves just part of what is done when we evaluate arguments.


The second criterion of cogent reasoning requires that we not pass over relevant infor- mation. In particular, it tells us to resist the temptation to neglect evidence contrary to what we want to believe.

Here, for instance, is a part of a column written in December 2015 by David Brooks in the New York Times in which he predicted a precipitous decline in Donald Trump’s support heading into the primary voting season:

When campaigns enter that final month, voters tend to gravitate toward the person who seems most orderly. As the primary season advances, voters’ tolerance for risk declines. They focus on the potential downsides of each contender and wonder, could this person make things even worse?

When this mental shift happens, I suspect Trump will slide. All the traits that seem charming will suddenly seem risky. The voters’ hopes for transfor- mation will give way to a fear of chaos. When the polls shift from registered voters to likely voters, cautious party loyalists will make up a greater share of those counted.



The voting booth focuses the mind. The experience is no longer about self- expression and feeling good in the moment. It’s about the finger on the nuclear trigger for the next 4 years. In an era of high anxiety, I doubt Republican vot- ers will take a flyer on their party’s future-or their country’s future.

We can summarize Brooks’ argument this way:

1. People are less likely to actually vote for risky candidates than they are to endorse them early in polls.

2. Voters who are more risk-averse are more likely to vote.

3. Trump is a risky candidate. (Implied)
:.4. Trump will not do as well in actual elections as he has in early polling and will

do less well in polls that focus on likely voters.

Trump then won 14 of the first 20 primary contests. Brooks was hardly alone in under- estimating Trump’s campaign, but his argument seemed particularly strong. He looked to historical elections and likely voting behavior and came to a reasonable conjecture based on those things.

However, two factors worked against Brooks. First and foremost, he did not consider relevant information about the electorate, especially the high level of frustration Repub- lican voters felt about their party’s leadership and “cautious party loyalists.” Second, Brooks may have been swayed by a bit of wishful thinking. As a moderate Republican and a (at least by New York Times standards) conservative, Brooks was very concerned about what a Trump nomination would mean for his party and country.


The third criterion of cogent reasoning requires that the premises of an argument genu- inely support its conclusion; or, as logicians like to say, it requires that an argument be valid, or correct. It is vitally important to understand that the validity of an argument has nothing whatever to do with the truth of its premises or conclusion. Validity concerns the nature of the connection between the premises and conclusion of an argument, not the truth or believability of its premises. Determining that an argument is valid tells us that (f we are justified in believing in its premises, then we also are justified in believing in the truth of its conclusion. It doesn’t tell us whether its premises are true. An argu- ment thus can be perfectly valid and have completely false premises, and even have a false conclusion. Here is an example: .

1. The New York Mets have won more World Series games than any other major league team. (False premise, alas!)

:.2. They have won more World Series games than the New York Yankees. (False conclusion, and even more heartbreaking for Mets fans.)

The argument is valid because if the Mets had won more World Series games than any other major league team, then, obviously (well, it’s obvious to baseball fans), they would have won more World Series games than the Yankees. The argument is valid, even though its premise and conclusion both are false. It’s valid because anyone who is justified in believing its premise is justified in believing its conclusion.


6. Two Basic Kinds of Valid Arguments

Premises may correctly support conclusions in two fundamentally different ways. The first way yields deductively valid arguments; the second, inductively valid (or inductively strong) arguments.4


The fundamental property of a deductively valid argument is this: If all of its premises are true, then its conclusion must be true also, because the claim asserted by its conclu- sion already has been stated in its premises, although usually only implicitly.

Here is an example of a very simple deductively valid argument:

1. If this wire is made of copper, then it will conduct electricity. (Premise.)

2. This wire is made of copper. (Premise.)
:.3. This wire will conduct electricity. (Conclusion.)

Taken alone, neither premise makes the claim that the wire will conduct electricity; but taken together, they do. We cannot imagine what it would be like for both premises of this argument to be true, yet its conclusion turns out to be false. Indeed, it would be con- tradictory to assert both of its premises and then to deny its conclusion.

It is important to see that it is the form of this argument- namely:

1. If some sentence, then _a_§~~9_11.4_s_~l}~C:l}~~’

2. The first sentence.
:.3. The second sentence-

that makes it deductively valid, not the truth values of its statements. Letting the capital letter A stand for the first sentence and B for the second sentence, the form of the argu- ment can be stated this way:

1. IfA,thenB.

2. A. :.3. B.

Clearly, every argument having this form is deductively valid, another example being this argument:

1. If Sonia reads Vogue magazine, then §\1_~’§_l}p_9!1_!l:i~_l_<!t~_s_t_~’!S.J:i!()l)~, 2. Sonia reads Vogue magazine.

:.3. $_!}~~s_!-lP..9_1}~!i~J’!~~s_t_f<!s.J:i!()l)~,

4Some authorities believe that there is at least one other kind of legitimate argument-namely, the kind in which various alternatives are evaluated. The authors of this text incline to the view that evaluative arguments fall into one or the other of the two basic kinds about to be mentioned. Note also that some authorities restrict the use of the term valid so that it refers only to deductively good arguments, even though in everyday life, inductively strong arguments generally are said to be valid. In addition, note that the reasoning process called “mathematical induction” happens to be a kind of deductive reasoning. (Terminology sometimes is misleading.)


Logicians, by the way, call the form of this argument, and every argument having this form, modus ponens. (We will consider modus ponens again in the next chapter, along with other valid argument forms.)

It’s very important to understand that the deductive validity of an argument guaran- tees that its conclusion is true only ifits premises are true. Determining that an argument is deductively valid thus tells us just that if its premises are true, then its conclusion must be true also; it doesn’t tell us whether its premises are true and thus doesn’t tell us whether its conclusion is true.

Here, for instance, is a deductively valid argument having the form modus ponens that contains one true and one very likely false premise, and thus does not guarantee the truth of its conclusion:

1. If more people read Agatha Christie’s mystery novels than read Shakespeare’s plays, then her novels must be better than his plays. (False premise?)

2. Her novels have been read by more people than have Shakespeare’s plays. (True premise.)

:.3. Her novels must be better than his plays. (False conclusion?)

Of course, a deductively valid argument that contains a false premise may have a true conclusion. But that would be a matter of luck, not of good reasoning.

Deductively valid arguments, then, can have false premises and a false conclusion, false premises and a true conclusion, or true premises and a true conclusion. The only combina- tion that a deductively valid argument cannot have is all true premises and a false conclusion.

The fact that a deductively valid argument cannot move from true premises to a false conclusion constitutes its chief characteristic and great virtue. When you present some- one with a deductively valid argument that has premises they know to be true, they must- on pain of irrationality- accept your conclusion! But deductive arguments are limited. They cannot yield conclusions that are not at least implicit in the premises from which they are derived. Induction is needed to perform this task.


Inductively valid (inductively strong) arguments, unlike deductively valid ones, have conclusions that go beyond what is contained in their premises. The idea behind valid induction is that of learning from experience. We often observe patterns, resemblances, and other kinds of regularities in our experiences, some quite simple (sugar sweeten- ing coffee), some very complicated (objects moving according to Newton’s laws- well, Newton noticed this, anyway) . Valid inductions simply project regularities of this kind observed in our experiences so far onto other possible experiences.5

Here is a simple example of an inductively valid argument, of the kind sometimes called induction by enumeration, expressed by a rather smart child in Jacksonville, Florida, explaining why he is doubtful about the existence of Santa Claus:

The tooth fairy turned out not to be real. The Easter Bunny turned out not to be real. So I’m beginning to wonder about Santa.

Admittedly this is a small sample, but perhaps not for a 4-year-old with a limited range of experience.

5This includes those experiences we can’t have but might have if we had lived millions of years ago, or if, say, we could go into the interior of the sun without being incinerated.

We use inductive reasoning so frequently in everyday life that its nature generally goes unnoticed. Being informed about induction is a bit like being told that we’ve been speaking prose all our lives. We start drawing perfectly good inferences of this kind (and some klinkers) at a very early age. By age 5 or 6, the use of induction has taught us a great many of the basic truths that guide everyday behavior-for instance, that some foods taste good and some don’t, the sun rises every morning and sets every evening, very hot things burn the skin, some people are trustworthy and some aren’t (something most of us seem to need to relearn over and over), and so on.

The great virtue of inductive reasoning is that it provides us with a way of reasoning to genuinely new beliefs, not just to psychologically new ones that are implicit in what we already know, as in the case of valid deductions. However, this benefit is purchased at the cost of an increase in the possibility of error. As remarked before, the truth of the premises of a deductively valid argument guarantees the truth of its conclusion; but the premises of a perfectly good induction may all be true and yet its conclusion false. Even the best “inductive leap” may lead us astray, because the patterns noticed in our experiences up to a given point may not turn out to be the exact patterns of the whole universe. This happens all too often in daily life-for example, when a restaurant that has served excellent food many times in the past fails us on a special occasion. But it sometimes happens even in the lofty realm of physics. Scientists, for instance, believed for a long time-based on strong inductive reasoning-that particles could not be colder than absolute zero, but then researchers discovered that atoms could be cooled to nega- tive absolute temperatures in a vacuum.

Nevertheless, rational people use induction in formulating their ideas about how things are going to turn out, whether in ordinary, everyday circumstances or in the rather special ones scientists bring about in the laboratory. Induction, thinking of Winston Churchill’s famous remark about democracy, is the worst way to expand one’s knowl- edge except for all of the other ways (guessing, wishful thinking, astrology, etc.).

7. Some Wrong Ideas About Cogent Reasoning

Having just presented three standards of cogent reasoning and having explained the nature of valid deduction and induction, perhaps we need to mention several recently voiced ideas about logic and good reasoning. According to these modestly trendy ways of looking at the topic, what counts as good reasoning is “culturally relative,” or “gender-relative,” or even “individually relative.” We hear talk of “feminine logic,” supposedly different from the “male logic” of logic classes (which has been developed, advanced, and taught by female logicians, but let that pass), and of “black intelligence,” different from the “Eurocentric” variety foisted on us by white males, as though what makes reasoning good differs from group to group, from race to race, or from one sex to the other. We all too often hear students say things such as “That may well be true for you, but it isn’t true for me,” and listen to academics talk disparagingly of “Aristotelian linear reasoning,” as opposed to a more “intuitive” type of reasoning, and so on.


A wise person hears one word and understands two.



Reading Between the Lines

The expression “reading between the lines” has several meanings. One captures the idea of grasping an intended thought that is not expressed, another of getting more information from a statement or argument than it explicitly-or even implicitly – contains, still another of noticing what rhetoric either deliberately or accidentally hides. Reading between the lines often is the essential ingredient in assessing a good deal of the everyday talk we all encounter, in particular political rhetoric and (interestingly) advertisements.

Take the Bufferin ad that states, “No regular aspirin product reduces fever better:’ Reading between the lines of this ad, we should conclude that Bufferin does not reduce fever better than some competing products, because if it did, the ad would make that stronger claim (“Bufferin reduces fever better than any other aspirin product”) rather than the weaker one that none reduces fever better. The point is that our own background beliefs should lead us to expect an advertisement to make the strongest claim possible and thus lead us to at least tentatively conclude that a less strong claim is made because stronger claims would be false.

Reading between the lines is the linguistic equivalent of “sizing up” other people-for example, of gleaning information about their beliefs or likely actions from their overt behavior or way of saying something. A good poker player, for in- stance, looks for signs of bluffing-some players often unwittingly signal a bluff by increasing chatter or by nervous behavior; others do so by feigning lack of concern. Similarly, intelligent voters try to size up political candidates by looking for nonver- bal clues and by reading between the lines of campaign rhetoric. (More will be said about campaign rhetoric in Chapters 7 and 10.)

But there is no truth to these ideas about what constitutes good reasoning. It is the height of folly to conclude, say, that an argument having the form modus ponens is not valid. Think, for example, what it means to assert seriously that all human beings have a right to life, and then in the next breath to claim, equally seriously, that a particular human being, Smith, has no right to life. What sense is there in first saying that if Jones has been to China, then he’s been to Asia, and then asserting that he has indeed been to China but not to Asia? Yet accepting reasonings that violate the standards of deductive logic means precisely accepting some sorts of contradictory assertions or other, because the point of the principles of valid deduction (including the valid principles of mathematics) is to assure that we do not contradict ourselves when we reason from one thing to another. (That’s why, to take just one of a thousand examples, double-entry bookkeeping works.)

Similarly, what reason could there be for violating the standards of good induc- tive reasoning-for denying what experience teaches us? That a large majority of the scientists who laid the groundwork in physics, chemistry, and biology were white males is totally irrelevant to the truth of their basic ideas and theories. The way the world works does not differ depending on the race or sex of those trying to discover the way the world works’ That is why, to take an everyday example, it is foolish to toss away money on homeopathic medicines: Medical science has shown, over and over again, by

means of inductive reasoning, to say nothing of very highly confirmed general biologi- cal principles, that homeopathy does not work. The point cannot be stressed too heavily. There simply is no truth whatsoever to the idea that standards of good reasoning differ from group to group, male to female, or person to person.

Doonesbury© G. B. Trudeau. Reprinted with permission of Universal Press Syndicate. All rights reserved.

There is, however, a good deal of truth to three much different ideas. One is that self-interest, prejudice, and/or narrow-mindedness do in fact often lead people to reason invalidly. Bigotry has a bad name for good reason. Another is that self-interest often mo- tivates us to neglect the values or interests of others, even when we share those values, so that some groups or individuals find their interests frequently neglected. For instance, rich people who believe fairness requires that everyone ought to have an equal chance when starting out in life often forget about equality of opportunity when they argue for the elimination of all inheritance taxes; in families in which both parents work, hus- bands notoriously tend to paper over their failure to share household and child-rearing duties; in the business world, high executives, while asserting their belief in equal rights for all, frequently overlook the ways in which women, Latinos, and blacks are often passed over for corporate advancement. In all of these cases, the problem is not with the principles of good reasoning. It is with the fallacious nature of the ways in which these principles sometimes are employed.

Those who champion other sorts of “logics” than the standard variety thus may well be mistaken in their target. They attack the principles of good reasoning rather than the failure of their opponents to employ these perfectly good (indeed the only good) stand- ards of reasoning correctly, or to reason from acceptable moral or other kinds of values.

A good deal more will be said in later chapters on these matters, in particular about moral and other value claims. For now, the point is just that we must distinguish the principles of good reasoning, which are the same for all, from the ways in which these principles are employed (sometimes fallaciously), and from the differing values that enter into the premises of different reasonings.

8. Background Beliefs

Earlier, we characterized cogent reasoning in terms of three conditions: the validity of connections between premises and conclusions, the believability of premises, and the discovery and use of relevant information. Clearly, satisfaction of the last two of these

Al\JD 15


three conditions requires the employment of background beliefs. That is why bringing one’s background beliefs to bear is among the most important tasks in evaluating an argument for cogency.

Consider, for example, the argument frequently heard in the early 1980s that AIDS was essentially a gay plague inflicted on homosexuals as punishment for their perverse sexual conduct (a claim still occasionally heard). Setting aside illegitimate assumptions about diseases being punishments and the “perversion” of homosexuality, the key prem- ise of this argument was that AIDS can be transmitted sexually only via homosexual conduct. This was supported by the evidence that in the United States, a large majority of those reported early on to have the disease were indeed homosexuals. But people with good background information did not accept this argument. For one thing, they knew that in other places around the world- for instance, in Haiti and parts of Africa- large numbers of heterosexuals also had contracted AIDS via sexual contact. And for another, those familiar with some of the basic scientific ideas concerning disease had theoretical (which means higher-level inductive) reasons for believing that AIDS could be transmitted via heterosexual behavior, as are syphilis, hepatitis B, herpes, and so on.

Today, most Americans know that AIDS is transmitted by both heterosexuals and homosexuals, but many people wrongly think that the disease is curable because they have heard about drugs used to treat HIV In fact, these drugs suppress the viral infection but do not cure it, and no vaccine has been successfully developed to date. Unfortu- nately, many young people believe they can be cured if they become infected and thus fail to take adequate precautions.

The point is that, contrary to the old saying, ignorance is not bliss. It just renders us incapable of intelligently evaluating claims, premises, arguments, and other sorts of rhetoric we all are subject to every day. When evaluating arguments and issues, we can’t bring relevant beliefs to bear if we don’t have them, and we cannot make good judg- ments if what we believe is off the mark.

9. Kinds of Background Beliefs

Background beliefs can be divided up in many different ways, an important one being a separation into beliefs about matters offact and beliefs about values. It is a factual ques- tion, for example, whether capital punishment is practiced in every society (it isn’t); it is a question of values whether capital punishment is morally justified (is it?). In dealing with most social or political issues, we need to separate claims that are about matters of fact from those concerning values, because these two different sorts of claims are defended, or justified, in different ways. T)1e statement, for example, that a given state has a death penalty is proved true, or false, by an examination of relevant government records; the judgment that capital punishment is, or isn’t, morally justified as the pun- ishment for heinous crimes is determined by bringing to bear an accepted moral code, or subjective intuitions.6

6Philosophers and others disagree seriously concerning the question whether there are such things as objective moral principles that all clear-minded, rational individuals are bound to see as cor- rect, or whether moral right and wrong is a matter of subjective opinion- of feelings that can, and perhaps do, differ from person to person.

Knowledge not renewed quickly becomes ignorance.

Those who cannot remember the past are condemned to repeat it. -GEORGE SANTAYANA

Background beliefs also can be divided into those that are true and (unfortunately) those that are false. Someone who believes, for example, that capital punishment exists as a practice in every society has a false belief; those who believe that every society punishes murderers in one way or another has a belief that is true. An important reason for regularly testing our background beliefs in terms of our experiences and of what we learn from others is precisely to weed out background beliefs that are false. Education consists of a lot more than simply learning a mountain of facts; it also has to do with weeding out beliefs that turn out to be false (or unjustified).

Beliefs also differ as to how firmly they are or should be held. We feel completely sure, completely confident, of some beliefs (for example, that the sun will rise tomor- row); less sure, but still quite confident, of others (for example, that the United States will still be in existence in the year 2050); and a good deal less sure, but still mildly confident, of others (for example, that we won’t get killed someday in an auto accident). The trick is to believe firmly what should be believed, given the evidence, and believe less firmly, or not at all, what is less well supported by evidence.

All of this relates directly to decisions we have to make in everyday life. Wise individuals take into account the probability of one thing or another happening and thus of the confidence they should place in their beliefs about what to do. That’s a large part of the truth behind familiar sayings such as “A bird in the hand is worth two in the bush.”

10. Worldviews or Philosophies

As we grow up from childhood into adults, we tend to absorb the beliefs and standards of those in the world around us~our families, friends, and culture. It is no accident that so many of us have the same religious affiliation, or lack of same, as do our parents, that we accept the principles and standards of our own society, and so on.

These beliefs constitute an important part of our worldviews or philosophies.7 They tend to be the most deeply ingrained and most resistant to amendment of all of our back- ground beliefs. They become so much a part of us that we often appeal to them without consciously realizing we have done so. They are so thoroughly woven into the fabric of our belief systems that we often find it hard to isolate and examine individual strands. And when we do examine them, our natural tendency is to reaffirm them without

7This includes religious beliefs in the case of those who have religious convictions.




thought and to disparage conflicting claims and evidence, quickly dismissing evidence that might count against them.

Most of these beliefs are general- for example, that killing always is morally wrong, that there is some good in virtually all human beings, or that we all die sooner or later. But not all are. Belief in a monotheistic deity, for instance, or rejection of such a belief, is a particular belief.

But in spite of the example just cited, general beliefs usually are more important than beliefs that are particular, or less general, because they tell us about a wider range of cases and thus tend to be more useful in everyday life. Believing that it rarely rains in July in Los Angeles, for instance, clearly is more useful than believing merely that it won’t rain there, say, on July 16, 2024. That is why most of the important beliefs in one’s worldview are general and also why most important scientific pronouncements are general-indeed, often extremely general. (Newton’s laws, for example, don’t just tell us about apples falling from trees or even just about items of all kinds falling toward Earth. They also tell us about the motion of Earth around the sun, about the motion of all planets around the sun, about how tides rise and fall, and, in fact, about the motions of all objects whatsoever.) It also is why it is so important, and useful, to expand our worldviews to contain at least a few modestly well-founded beliefs about important sci- entific theories-for example, about the theory of the evolution of all life on Earth.

Our Words and Worldviews

The worldviews ofpolitical parties are implied in the words and phrases they use repeat- edly in their discourse. University ofCalifornia linguist George Lakoffcame up with a list ofwords used over and over in the speeches and writings ofconservatives and liberals. It’s worth examining them to figure out the dominant worldviews reflected in the language.*

Conservatives: character, virtue, discipline, tough it out, get tough, tough love, strong, self-reliance, individual responsibility, backbone, standards, authority, heri- tage, competition, earn, hard work, enterprise, property rights, reward, freedom, intrusion, interference, meddling, punishment, human nature, traditional, common sense, dependency,self-indulgent, elite,quotas,breakdown,corrupt, decay, rot,de- generate, deviant, lifestyle.

Liberals: social forces, social responsibility, free expression, human rights, equal rights, concern, care, help, health, safety, nutrition, basic human dignity, oppression, diversity, deprivation, alienation, big corporations, corporate welfare, ecology, eco- system, biodiversity, pollution.

What worldviews are indicated by the repetition of these words?Reflect a moment on the assumptions you used to come to these conclusions. Specifically, which of the words above do you think were typically used with a negative connotation?

*Taken from Lakoff, G. Moral Politics: How Liberals and Conservatives Think. Chi- cago: University of Chicago Press, 2002.

Compare the worldview reflected in this gem, excerpted from a 1950s women’s magazine, to your worldview.

From “Runaway Husbands” by Barbara Heggie

Somehow, in her battle for equal rights, the American woman has con – vinced herself that one o f these rights is the love o f her husband. She should be reminded that love is not an obligation, but a reward for favors received-for affection, for solicitude, above all for making her husband feel he is the center o f her own particular universe. What I had seen in the bleak faces o f the deserted wives I had talked to was the knowledge they had failed in the biggestjob a woman can accept.


11. Insufficiently Grounded Beliefs

Most of us have strongly held beliefs about a great many controversial issues, and so we tend to respond automatically to arguments about these matters. We feel confident that we know whether marijuana should be legalized, whether we should privatize Social Security, whether this candidate or that is more likely to serve all of the people equally if elected to office, and so on. We hold these beliefs, often very strongly, even though a good deal of the time we have insufficient justifying background knowledge and have engaged in too little thought to be able to support our beliefs intelligently or defend them against informed objections. What, for example, do we usually know about candidates running for seats in the U.S. House of Representatives? (Every election year, a significant number of voters do not know the names of both major-party candidates for congres- sional seats in their districts; fewer still can name both candidates for state legislatures in their districts. Could you?) Too often, we base our ,vote on our party affiliation and not on the merit of individual candidates. Worse still, voters sometimes decide on the basis of name recognition alone. Clearly, then, weeding out insufficiently grounded background information is vital if we are to improve our reasoning about important, to say nothing of relatively trivial, matters. (It also might be a good idea to find out something about candi- dates for various offices before stepping into a booth and casting our ballots.)

Having well-supported background beliefs is particularly important with respect to those basic background beliefs that make up our worldviews. Worldviews are like lenses that cause us to see the world in a particular way or filters through which we pro- cess all new ideas and information. Reasoning based on a grossly inaccurate or shallow worldview tends to yield grossly inaccurate, inappropriate, or self-defeating conclusions (except when we’re just plain lucky), no matter how smart we otherwise may be. Some- times, the harm is relatively minor (gamblers who waste a few bucks playing “lucky” lottery numbers; astrology column readers who arrange vacation times to fit their sign), but at other times, the harm can be more serious (people with an overly rosy view of



human nature who get taken by con artists; misanthropes who miss out on the benefits and joys of trusting relationships).

Obviously, then, we need to examine our background beliefs, especially those that make up our worldviews, for consistency and believability, and we need to amend them so as to square with newly acquired information. The point is that having a good supply of background beliefs is not just a matter of filling up one’s “tank” with gallons of facts . It is at least equally important to improve one’s existing stock of beliefs by weeding out those that experience proves to be false, to sharpen vague beliefs, and to replace crude beliefs with those that are more sophisticated- beliefs that penetrate more deeply into the complexities of life and the world.

People who hold different worldviews often clash on a personal level, but when cultures or nations have conflicting worldviews, they can create tension and spark an- tagonism internationally. One recent example involved a controversy over whether an Afghan should be sentenced to death because he converted from Islam to Christianity. Under Sharia law, a Muslim who rejects Islam may be tried and executed. So when it became known that the man had converted to Christianity, he was put on trial by the Afghan government, whose constitution allows prosecution under Sharia law. When Muslim clerics demanded that he be sentenced to death, prominent leaders in the West- ern world urged the government to honor human rights principles and free him. The conflicting worldviews caused an uproar on both sides. When the Afghan government looked for ways to drop the case in order to comply with international pressure, the cler- ics warned that if the man were freed, the people of Afghanistan would kill him. (The government resolved this dilemma by declaring him mentally unfit and citing “investi- gative gaps” in the case.) When clashes like this multiply and escalate, they can lead to serious international conflict and even large-scale violence.

The Cost of Entrenched Worldviews

It is worth noting here that widespread failure to revise worldviews often results in serious political and social unrest and injustice.E. M.Forster capturesthispoignantly in his novel A Passage to India, in which he depicts intense conflicts in colonial India between English masters and their conquered Indian subjects. Believing them- selves socially and racially superior, the English relegate the Indiansto subordinate positions, never allowing them equality under the British raj. The insensitivity of the British to the plight of their subjects is met with resentment, distrust, anger, and threats of violent retaliation by the Indians. (To make matters worse, the Indians are divided from one another by differing religiousand cultural beliefs.)Very few ofthe British or IndiansForster depictsever revise their biases and prejudicesin the light of new information-for instance, in the light of obvious evidence about the competence of individual Indians or the glaring prejudice of English officials. The novel makes a compelling case for a widespread reexamination of worldviews and other background beliefs if human beings are to arrive at a peaceful, nonex- ploitative coexistence on planet Earth.

Socrates is said to have claimed that the unexamined life is not worth living.8 While clearly an exaggeration, there surely is a great deal of truth in this idea. By the same token, there is a large dose of truth in the idea that an unexamined worldview is not likely to be worth holding , in particular because it will contain little more than an accumulation of the ideas and prejudices of others. Examining worldviews allows us to take control of our lives by actively sorting out our fundamental beliefs, testing them against ideas and information that point to conclusions contrary to what we already believe, and making whatever revisions are indicated in the light of what we have learned. Doing this helps us to become our own person rather than just a passive follower ofothers!

Unfortunately, it is no easy matter for us to examine our worldviews objectively. Psychological studies show that people hold on to their beliefs for dear life, ignoring evidence that undermines them and dredging up weak evidence to support them. This obstacle to rational thought is compounded by our natural tendency to take short-cuts in reasoning that reduce our mental effort, allowing us to slide past unwelcome evidence and leap to hasty conclusions that support our existing beliefs. All this makes rational self-analysis difficult, to say the least-but not impossible. To reason cogently, we need to fight this human tendency (discussed further in Chapter 6).

12. Two Vital Kinds of Background Beliefs

Background beliefs obviously differ greatly in their importance-that is to say, their propensity to affect (or even determine) our everyday judgments. Two kinds that are extremely important in this way concern the nature ofhuman nature and the reliability ofinformation sources.


Beliefs about what we ourselves and other people are like constitute a vital part of everyone’s worldview. They are crucial in applying what we know to the problems en- countered in everyday life, whether of a personal or a social nature. When can we trust our friends? Is an instructor to be believed who says that students are graded solely on the quality of their exams and not on agreement with the instructor’s personal opinions? Will people be sufficiently motivated to work diligently under a socialistic system? Are large numbers of elected officials motivated by selfish interests that frequently override their sense of duty to those who have elected them?

Fortunately, we don’t have to start constructing theories about human nature from scratch, since other people, including some of the great writers (Shakespeare, Aristotle, Darwin, Freud) have been at the task for some time now. (Of course, tapping these sources has its risks. Freud, for instance, had some way-off-target ideas on the subject to go along with some extremely penetrating ones.)

8Note, however, that psychology has just recently come out of its infancy. Note also that there is more chicanery in medical research (because of the profit motive?) than in most other areas of science.



Thoughts about the accuracy, sufficiency, and truthfulness of information sources consti- tute another vital kind of background belief. As with computers, so also with the human mind: “Garbage in, garbage out.” We therefore need constantly to reassess the reliability of important information sources-television, newspapers, magazines, friends, the Internet, teachers, textbooks, and so on. Under what conditions are these sources likely to provide truthful or, at least, sensible information or opinions? When are alleged ex- perts likely even to possess the truth, much less be motivated to tell it to us straight? When are they likely to be prejudiced in ways that may cloud their judgment? We can’t assume automatically that a source is reliable without some reason for believing this. As lamented a while back, many people seem to think that if they read it in print or hear it on the TV evening news, then it must be true. Sophisticated reasoners, however, realize that these information sources do not always furnish “the truth, the whole truth, and nothing but the truth”; they don’t necessarily provide us with “All the news that’s fit to print” (the New York Times motto), instead sometimes shaving matters either out of ig- norance or from self-serving motives. Intelligent viewers of the scene thus try to deter- mine when these sources are likely to be reliable and when not. That is why Chapter 10 deals with advertising as an information source, Chapter 11 with the reliability of the news media, and Chapter 12 with new media.

13. Science to the Rescue

The mention of Darwin and Freud a while back brings to mind the central place that science plays in modern life and in the construction of accurate stocks of background beliefs- in particular, in the formulation of sensible worldviews. Although no informa- tion source is absolutely reliable and no theory exempt from at least a small measure of doubt, the most reliable, the most accurate information comes from the well-established sciences of physics, chemistry, biology, and, to a lesser extent, psychology, the social sciences, and the applied sciences such as engineering.The scientific enterprise is an or- ganized, ongoing, worldwide activity that builds and corrects from generation to genera- tion. The method of science is just the rigorous, systematic, dogged application of cogent inductive reasoning, mixed with all sorts of deductive- including mathematical- reasoning from what has so far been observed over many centuries to theories about how the universe and the many things in it have functioned and are likely to function. Theories falsified by experience are tossed out, no matter whose pet ideas happen to get stepped on. Absolutely no one, starting from scratch, could hope to obtain, in one life- time, anything remotely resembling the sophisticated and accurate conclusions of any of the sciences, even if that person were a Galileo, Newton, Darwin, and Einstein all rolled into one. It is foolish indeed to dismiss what science has to say on any topic without very careful thought and without having extremely important reasons for doing so!9

9It is worth noting that this comes to us from the “Apology,” Plato’s (probably somewhat fictional- ized) account of Socrates’s trial, where he was accused largely of “examining” himself and others and where he was ultimately sentenced to death.

Indeed, one justification for requiring all high school students to take at least one course in a physical or biological science is to allow them to gain an understanding of the great rigor with which scientific principles are tested and proved. But another, easier way to come to understand the power of science as compared to other ways of finding out about the world is to think carefully about the thousands of everyday items available to us today that did not exist 300 years ago, products that owe their existence to the tre- mendous advances in scientific theory that have been made since the days of Galileo and Newton. Without science, there would be no automobiles, no airplanes (not to mention spacecraft), no telephones, no electric lightbulbs, no air conditioning, no other electric devices of any kind (certainly no computers!), no batteries, no aspirin or other common painkillers, no anesthetics (alcohol used to be the painkiller used during amputations), no antibiotics (or even knowledge of the ~xistence of microbes and thus the extreme importance of cleanliness), no ways to purify drinking water, no indoor plumbing, no eyeglasses, no insulin for diabetics, … the list goes on and on. Instead, there were plenty of mosquitoes and flies (and fly paper) everywhere on summer days, and people made do with commodes, outhouses, and well-drawn drinking and washing water. In those days, doctors could cure only a handful of ailments, horse dung and its foul smell were everywhere in every city and town, lighting after dark was furnished by candles or oil lamps, and so on. Before the existence of the scientific, modern, industrial world, the average life span almost everywhere was less than 50 years, much less in most societies.

Of course, to avoid having beliefs contradicted by scientific theory or to apply scien- tific principles successfully in dealing with everyday problems, one does have to have at least a casual acquaintance with what science has to say on various topics. The problem is that large numbers of people have no idea what science is up to and have only the tini- est stock of scientific facts about the nature of the world. This lack of knowledge about science can have unfortunate consequences. For instance, a growing number of parents have refused to vaccinate their children against measles on the mistaken belief that vac- cines are ineffective preventatives and may even be harmful. They believe that a healthy diet and good living is enough and that their refusal to use vaccinations won’t affect anyone but their own children. None of these assumptions is accurate, however. A study published in the Journal ofthe American Medical Association of measles cases over the last 15 years found that recent increases in measles cases correlate with the increase in vaccine refusals. For immunizations to be effective, a high percentage of children need to be vaccinated to protect the population at large. Ignoring the science has resulted in outbreaks of measles, which the Center for Disease Control was able to declare eradi- cated from the United States before the anti-vaccination movement took root

Unfortunately, it isn’t just the average person (or average college graduate?) who is more or less illiterate when it comes to science. Even those who need to know about specific scientific results in order to do their jobs adequately are frequently remiss in this way. During a quite severe drought in California, one government official defended his inaction by stating that “One problem [in deciding whether to enact water rationing measures] is that we have only 110 years of [precipitation] records. Our statistics [on California droughts] aren’t very good.” Yet, just prior to that time, a U.S. Geological Survey study of giant sequoia tree rings had yielded a record going back more than 2,000 years.



Students sometimes defend their ignorance of science by arguing that they only need to know the science, if any, that is relevant to the job they will perform after graduation from college. But this is a serious mistake. For one thing, it isn’t possible to know now what basic scientific ideas will be relevant to a job held several years down the pike. (It isn’t really possible, except in unusual cases, to know what sort of job it will be, much less what kinds of knowledge will be relevant to it.) In this increasingly technological age, more and more jobs require at least a general idea of what science has to say about various topics.

More to the point, a rudimentary understanding of science also is of immeasurable value when dealing with all sorts of everyday problems that aren’t related to earning a living. Consumers spend millions of dollars every year on over-the-counter nostrums that don’t work, or may even be harmful, because they don’t know simple scientific facts- for instance, that no remedies they can buy will cure the flulike infections common in

A Crisis in Psychology?

It may be that not all fields that we call “science” are quite as reliable as the devel- oped natural sciences (physics, biology, botany, etc.).This is not a disparagement of so-called “soft science” (roughly the social sciences: psychology, economics, political science, etc.). Work in these fields is often rigorous, fascinating, and useful. And we have much to learn from it.

But at the same time, it may not be quite as simple to rely on results in these fields.Take for instance a recent controversy in social psychology. One key criterion for a scientific result is reproducibility. A successful experiment ought to be able to be conducted again and again by anyone and a.lways yield the same result. If not, then those results are at least subject to doubt if not thrown out entirely. How- ever, in August 2015, a study by the “Reproducibility Project” found that the results of fewer than 40 percent of the 100 experiments published in major psychology journals were reproducible. Social psychology fared particularly badly, coming in at 25 percent.

To be fair, many experimental psychologists have argued that the contro- versy over these findings and the significant media coverage that followed them was overblown. As Lisa Feldman Barrett, a psychology professor at Northeastern claimed in the New York Times, “the failure to replicate is not a cause for alarm; in fact, it is a normal part of how science works … It is what leads us along the path- thewonderfullytwistypath-ofscientificdiscovery:’ 11:1:

One problem with public scientific knowledge in general is that results of scien- tists’ work are often publicized prematurely and misrepresented in the mass media. The lesson here is not that we shouldn’t trust psychology or any other social science, but that maybe we should wait a bit until discoveries in these fields (and maybe to some extent in the hard sciences, too) are a little further along Professor Barrett’s “wonderfully twisty path” before we fully take them on board. But once results are successfully replicated and agreement on a certain hypothesis approaches scientific consensus, we have all the reason in the world to accept it.

winter. Every day, people throw their money away on get-rich-quick schemes that defy the most basic principles of economics. Large sums are wasted on fortune tellers, medi- ums, and other charlatans whom science has proved over and over again cannot deliver the promised goods. (This point is discussed a bit more in Chapter 6.)

Students often are put off science by the sheer complexity of the subject matter. Biology, for example, has to be an extremely complicated science, given that the bodies of complex living organisms like humans contain trillions of cells, each one of which contains millions of atoms and subatomic particles. (Did you know this?) So the bad news is that every science quickly goes over the heads of almost all laypeople. But the good news is that with only modest perseverance, people who are reasonably intelligent can learn enough about science to greatly improve their everyday reasoning and thus their chances of success in everyday life. (Clearly, similar remarks apply to mathemat- ics, particularly to arithmetic and simple algebra-note the confusion that occasionally results in supermarkets when the power goes out and clerks need to actually add and subtract to figure out what is owed.)

Summary of Chapter 1

Reasoning is the essential ingredient in solving life’s problems.This chapter discusses some of the fundamentals of good reasoning and presents an overview of the material to be covered later on the topic of reasoning well in everyday life.

  1. Reasoning can be cast into arguments, which consist of one or more premises (reasons) offered in support of a conclusion. In real life (as opposed to in textbooks), arguments usually are not labeled and divided from surrounding rhetoric, nor are their premises and conclusions neatly specified. But clues generally are given. Logical indicators such as because, since, and for usually signal premises; hence, therefore, and so, conclusions.
  2. Not all groups of sentences form arguments.They may be anecdotes or other types of exposition or explanation. Explanations are especially prone to be confused for arguments. In most cases, explanations are meant to show how some claim came to be true, while arguments are meant to persuade us that some claim is true.
  3. For our purposes, “winning an argument” means more than just persuading an audience. It means persuading an audience based on a rational inference from premises to conclusion .
  4. Reasoning is either cogent (good) or fallacious (bad). Cogent reasoning must satisfy three criteria: It must (1) start with justified (warranted, believable) premises, (2) include all likely relevant information, and (3) be valid (correct).
  5. There are two basic kinds of valid reasoning: deductive and inductive. The fundamental property of a deductively valid argument is this: If its premises are true, then its conclusion must be true also. This is so because the conclusion of a deductively valid argument already is contained in its premises, although usually implicitly, not explicitly. (Note that a deductively valid argument may have false



premises. What makes it valid is that if its premises are true, then its conclusion must be also.) Unlike deductively valid arguments, those that are inductively valid (inductively correct, strong) have conclusions that go beyond the claims made by their premises, projecting patterns stated in the premises onto additional cases .

  1. There is no truth to claims about there being such things as “feminine logic;’ different from “male logic:’ Logic is not “gender-relative:’ Similarly, there is no truth to the idea that something exists called “black logic;’ different from the “Eurocentric” variety espoused by white male teachers. Good reason ing does not differ from sex to sex or from race to race; it is not in any way tied to ethnicity. Furthermore, with respect to facts, at any rate, the idea embodied in the idea that “It may well be true for you, but it isn’t true for me” is without merit, as is the academic talk of there being something called “Aristotelian linear reasoning;’ different from a more “intuitive” type of reasoning. (But more needs to be said, and will be, about beliefs concerning values.The point made in this chapter is that, however we may arrive at value beliefs, reasoning from those beliefs must employ the same principles of logic as does reasoning about purely factual matters.)
  2. Background beliefs can be divided in many ways, one being into beliefs about matters offact (snow is white) and beliefs about values (Jane Austen’s novels are better than those of Stephen King). (Note that when speaking of beliefs here, we have in mind a broad sense covering everything accepted as true, or very likely true, and all value judgments and convictions.)
  3. Beliefs also, of course, can be divided into those that happen to be true and those that are false. They also can be differentiated in terms of how firmly they are or should be held, and with respect to whether they concern particular events (Jones went to the show last Wednesday) or those that are general (copper conducts electricity).
  4. Our most important beliefs, taken together, make up our worldviews or philosophies. They are particularly important because they enter into decisions of all kinds-about what to do or what to believe-that we need to make in everyday life. Examples: We all die sooner or later; it’s always wrong to betray a friend; the best way to find out about how things work is to use induction and deduction. Note that, although most beliefs in our worldviews are genera l- even extremely general-a few are not. Example: We don’t know whether there is or isn’t a God (part of the worldviews of agnostics).
  5. Unfortunately, we all tend at least sometimes to hold a belief without sufficient reason for doing so-for example, when complicated social or political issues are discussed. This is true even with respect to some of the beliefs that make up our worldviews. But worldviews, just as any beliefs, need to be carefully examined: Does evidence support them? Do we really value this more than that? Having an

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accurate supply of background beliefs is not just a matter of regularly acquiring more beliefs but also of pruning those we already have.

We tend to absorb the beliefs of those around us as we mature from children into adults. Our worldviews, in particular, tend to grow out of family values, religious training, peer group attitudes, cultural heritages, and so on. We often hold these vital beliefs uncritically-indeed, often without realizing that we hold them. Good critical reasoners, on the contrary, try to become aware of and to critically evaluate their background beliefs, especially those making up their worldviews.

Beliefs about human nature are of vital importance when reasoning in daily life, because the success or failure of everyday interactions depends on them. Whether we can trust this sort of person or that is an example. That is one rea- son why reading the writings of great literary and scientific figures is so useful (in addition to being entertaining).

Beliefs about the accuracy and truthfulness of information sources also are of great importance, because, as the saying goes, “Garbage in, garbage out:’ We can’t reason well from poor or false information. That is why later chapters in this book deal with several important information sources.

Because science plays such an important part in everyone’s life these days, it behooves us to become as well acquainted as we can, and as time permits,
with the scientific view of the world and with the ways in which scientists come to their conclusions. No one on his or her own cou ld possibly discover even a tiny fraction of what scientists have learned over hundreds of years about the way the world works. (Those who don’t see the importance of science in their own lives should reflect on how much we depend, every day, on the fruits of scientific investigations. Examples: Electrical devices, painkillers and other mod- ern medicines, toilet paper.) Unfortunately, most people do not have even a reasonably good grasp of what science is up to.



Identify the premises and conclusions in the following arguments. (A few are from student exams-modestly edited.)10 Remember, sometimes a premise or conclusion may be implied.



The barometer is falling sharply, so the weather is going to change.

Argument Structure
Premise: The barometer is falling sharply.
Implied premise: Whenever the barometer falls sharply, the weather changes. Conclusion: The weather is going to change.

10Starred (*) items are answered in a section at the back of the book.


  1. Since everyone deserves health care, and 30 million Americans still don’t havemedical insurance, the United States should institute national insurance.
  2. I have my doubts about genetically modified plants. To begin with, we don’t have enough information about them to know if they are bad for us in the long run. Then there is the problem of cross contamination if they spread to other areas. The whole thing seems pretty questionable.
  3. The legacy of the New England Patriots will forever be tarnished, no matter how many Super Bowls they win.They have a long history of cheating, whether we’re talking about filming other teams’ practices, lying about injuries, or deflating game balls. And that’s just the stuff we know about! The truly legendary teams win like the Patriots, but unlike the Patriots, they do it the right way.
  1. *4.  William Shakespeare: “Forbear to judge, for we are sinners all:’
  2. *5.  Why not legalize drugs? One thing for sure, we would get rid of the crime syndicates that run the show now. Instead of giving money to the drug lords, the government would rake in billions in taxes. Maybe even enough to pay down the debt.
  1. Aristotle:”The Earth has a spherical shape. For the night sky looks different in the northern and the southern parts of the Earth, and that would be the case if the Earth were spherical in shape:’
  2. Human activities have become the major source of global warming. Over the past 200 years, they have been responsible for the rising carbon dioxide levels from burning fossil fuels and for increased concentrations of other greenhouse gases like methane and nitrous oxide.

*8. Several years ago, National Football League quarterback Michael Vick was convicted of sponsoring illegal dogfights and performing acts of cruelty to animals. But he has served his time in federal prison and has worked with the Humane Society to help stamp out dogfighting among young people. So his criminal record shouldn’t prevent him from getting into the Pro Football Hall of Fame. He was a great quarterback for the Atlanta Falcons before his prison time, and he made a great comeback with the Philadelphia Eagles. He deserves the honor.

  1. College costs big bucks. When you put out that kind of money, you should be able to decide where your money goes. Students shouldn’t have to take in- troductory courses if they don’t want to. Besides, you don’t need those basic courses for lots of careers.
  2. Giving illegal aliens driver’s licenses would undermine our immigration laws. After all, they are here illegally to begin with. Besides, there is the security issue. If anyone can get a license, so can terrorists, and that means they can fly anywhere in the country with just a license for an ID. Who knows how many planes they might blow up?

How to Improve Critical Thinking

Imagine if you could learn how to organize your thoughts in a way that could not only make your job easier, but also lead you to become a better solution-finder. In this experiential course you will learn how and when to pose the most fit questions and have insight into other people’s perspectives with a clear understanding.

How you will benefit:

  • analyze real-life situations to see why critical thinking is a crucial part of business
  • use critical thinking in important business decisions
  • detect 8 obstacles that hinder the path to critical  thinking
  • learn how to turn an intangible idea into something real
  • learn to detect 7 qualities of a feeble argument
This training course will cover:Recognizing the Value of Using Critical Thinking in Business


  • Defining critical thinking
  • Characteristics of effective critical thinkers
  • The role of critical thinking in meeting business challenges

A Critical Thinking Process

  • Using a framework to relate critical thinking to business challenges
  • Describing critical thinking using the RED (Recognize assumptions, Evaluate arguments, Draw conclusions) Model
  • Positioning the RED Model within a critical thinking framework

Obtaining Feedback on Your Critical Thinking Skills

  • Recognizing the value of gaining insight into one’s critical thinking skills
  • Relating critical thinking skills to other business skills
  • Uses for the “My Thinking Styles” assessment
  • “My Thinking Styles” Development Report
  • Your personal “Thinking Styles” Development Report

A Context for Critical Thinking

  • Identifying personal situations where critical thinking has been and could be used
  • Selecting techniques for using critical thinking skills and the RED model
  • Relating insight from your “Thinking Styles” report and feedback to a personal critical thinking situation

Applying Critical Thinking Tools and Skills in Business Situations

    • Practicing using critical thinking skills and techniques in a real business situation
    • Initial action plan for development of critical thinking skills