Standard Form Arguments
Chapter 1
1.1 What Is Critical Thinking?
What is critical thinking? What is a critical thinker? Why do you need a guide to think critically? These are good questions, but ones that are seldom asked. Sometimes people are afraid to ask questions because they think that doing so will make them seem ignorant to others. But admitting you do not know something is actually the only way to learn new things and better understand what others are trying to tell you.
There are differing views about what critical thinking is. For the most part, people take bits and pieces of these views and carry on with their often imprecise—and sometimes conflicting—assumptions of what critical thinking may be. However, one of the ideas we will discuss in this book is the fundamental importance of seeking truth. To this end, let us unpack the term critical thinking to better understand its meaning.
First, the word thinking can describe any number of cognitive activities, and there is certainly more than one way to think. We can think analytically, creatively, strategically, and so on (Sousa, 2011). When we think analytically, we take the whole that we are examining—this could be a term, a situation, a scientific phenomenon—and attempt to identify its components. The next step is to examine each component individually and understand how it fits with the other components. For example, we are currently examining the meaning of each of the words in the term critical thinking so we can have a better understanding of what they mean together as a whole.
Analytical thinking is the kind of thinking mostly used in academia, science, and law (including crime scene investigation). In ordinary life, however, you engage in analytical thinking more often than you imagine. For example, think of a time when you felt puzzled by someone else’s comment. You might have tried to recall the original situation and then parsed out the language employed, the context, the mood of the speaker, and the subject of the comment. Identifying the different parts and looking at how each is related to the other, and how together they contribute to the whole, is an act of analytical thinking.
When we think creatively, we are not focused on relationships between parts and their wholes, as we are when we think analytically. Rather, we try to free our minds from any boundaries such as rules or conventions. Instead, our tools are imagination and innovation. Suppose you are cooking, and you do not have all the ingredients called for in your recipe. If you start thinking creatively, you will begin to look for things in your refrigerator and pantry that can substitute for the missing ingredients. But in order to do this, you must let go of the recipe’s expected outcome and conceive of a new direction.
Critical thinking involves carefully assessing information and its sources.
When we think strategically, our focus is to first lay out a master plan of action and then break it down into smaller goals that are organized in such a way as to support our outcomes. For example, undertaking a job search involves strategic planning. You must identify due dates for applications, request letters of recommendations, prepare your résumé and cover letters, and so on. Thinking strategically likely extends to many activities in your life, whether you are going grocery shopping or planning a wedding.
What, then, does it mean to think critically? In this case the word critical has nothing to do with criticizing others in a negative way or being surly or cynical. Rather, it refers to the habit of carefully evaluating ideas and beliefs, both those we hear from others and those we formulate on our own, and only accepting those that meet certain standards. While critical thinking can be viewed from a number of different perspectives, we will define critical thinking as the activity of careful assessment and self-assessment in the process of forming judgments. This means that when we think critically, we become the vigilant guardians of the quality of our thinking.
Simply put, the “critical” in critical thinking refers to a healthy dose of suspicion. This means that critical thinkers do not simply accept what they read or hear from others—even if the information comes from loved ones or is accompanied by plausible-sounding statistics. Instead, critical thinkers check the sources of information. If none are given or the sources are weak or unreliable, they research the information for themselves. Perhaps most importantly, critical thinkers are guided by logical reasoning.
As a critical thinker, always ask yourself what is unclear, not understood, or unknown. This is the first step in critical thinking because you cannot make good judgments about things that you do not understand or know.
The Importance of Critical Thinking
Can you recall a time when you acted or made a decision while you were experiencing strong emotions? Relying on our emotions to make decisions undermines our ability to develop confidence in our rational judgments. Moreover, emotional decisions cannot typically be justified and often lead to regret.
Why should you care about critical thinking? What can it offer you? Suppose you must make an important decision—about your future career, the person with whom you might want to spend the rest of your life, your financial investments, or some other critical matter. What considerations might come to mind? Perhaps you would wonder whether you need to think about it at all or whether you should just, as the old saying goes, “follow your heart.” In doing so, you are already clarifying the nature of your decision: purely rational, purely emotional, or a combination of both.
In following this process you are already starting to think critically. First you started by asking questions. Once you examine the answers, you would then assess whether this information is sufficient, and perhaps proceed to research further information from reliable sources. Note that in all of these steps, you are making distinctions: You would distinguish between relevant and irrelevant questions, and from the relevant questions, you would distinguish the clear and precise ones from the others. You also would distinguish the answers that are helpful from those that are not. And finally, you would separate out the good sources for your research, leaving aside the weak and biased ones.
Making distinctions also determines the path that your examination will follow, and herein lies the connection between critical thinking and logic. If you decide you should examine the best reasons that support each of the possible options available, then this choice takes you in the direction of logic. One part of logical reasoning is the weighing of evidence. When making an important decision, you will need to identify which factors you consider favorable and which you consider unfavorable. You can then see which option has the strongest evidence in its favor (see Everyday Logic: Evidence, Beliefs, and Good Thinking for a discussion of the importance of evidence).
Consider the following scenario. You are 1 year away from graduating with a degree in business. However, you have a nagging feeling that you are not cut out for business. Based on your research, a business major is practical and can lead to many possibilities for well-paid employment. But you have discovered that you do not enjoy the application or the analysis of quantitative methods—something that seems to be central to most jobs in business. What should you do?
How Lack of Wisdom Creates Problems
Psychologist Barry Schwartz tells a story of how a simple error—and arguably a lack of critical thinking—led a family to fall into the child protective system.
Critical Thinking Questions
This clip is from a TED Talk in which Barry Schwartz makes a passionate call for what he calls "practical wisdom" as an antidote to bureaucracy. Based on this clip, what do you think he means by "practical wisdom"? What is its relationship to critical thinking? How do you think one can develop practical wisdom?
According to Schwartz, rules often fail us: "Real-world problems are often ambiguous and ill-defined, and the context is always changing. . . . A wise person knows when and how to make the exception to every rule . . . a wise person knows how to improvise." What are some rules that you tend to follow that you think you could break and actually create better outcomes at work, your home, and in your relationships?
Many would seek advice from trusted people in their lives—people who know them well and thus theoretically might suggest the best option for them. But even those closest to us can offer conflicting advice. A practical parent may point out that it would be wasteful and possibly risky to switch to another major with only 1 more year to go. A reflective friend may point out that the years spent studying business could be considered simply part of a journey of self-discovery, an investment of time that warded off years of unhappiness after graduation. In these types of situations, critical thinking and logical reasoning can help you sort out competing considerations and avoid making a haphazard decision.
We all find ourselves at a crossroads at various times in our lives, and whatever path we choose will determine the direction our lives will take. Some rely on their emotions to help them make their decisions. Granted, it is difficult to deny the power of emotions. We recall more vividly those moments or things in our lives that have had the strongest emotional impact: a favorite toy, a first love, a painful loss. Many interpret gut feelings as revelations of what they need to do. It is thus easy to assume that emotions can lead us to truth. Indeed, emotions can reveal phenomena that may be otherwise inaccessible. Empathy, for example, permits us to share or recognize the emotions that others are experiencing (Stein, 1989).
The problem is that, on their own, emotions are not reliable sources of information. Emotions can lead you only toward what feels right or what feels wrong—but cannot guarantee that what feels right or wrong is indeed the right or wrong thing to do. For example, acting selfishly, stealing, and lying are all actions that can bring about good feelings because they satisfy our self-serving interests. By contrast, asking for forgiveness or forgiving someone can feel wrong because these actions can unleash feelings of embarrassment, humiliation, and vulnerability. Sometimes emotions can work against our best interests. For example, we are often fooled by false displays of goodwill and even affection, and we often fall for the emotional appeal of a politician’s rhetoric.
The best alternative is the route marked by logical reasoning, the principal tool for developing critical thinking. The purpose of this book is to help you learn this valuable tool. You may be wondering, “What’s in it for me?” For starters, you are bound to gain the peace of mind that comes from knowing that your decisions are not based solely on a whim or a feeling but have the support of the firmer ground of reason. Despite the compelling nature of your own emotional barometer, you may always wonder whether you made the right choice, and you may not find out until it is too late. Moreover, the emotional route for decision making will not help you develop confidence in your own judgments in the face of uncertainty.
In contrast, armed with the skill of logical reasoning, you can lead a life that you choose and not a life that just happens to you. This power alone can make the difference between a happy and an unhappy life. Mastering critical thinking results in practical gains—such as the ability to defend your views without feeling intimidated or inadequate and to protect yourself from manipulation or deception. This is what’s in it for you, and this is only the beginning.
Everyday Logic: Evidence, Beliefs, and Good Thinking
It is wrong always, everywhere, and for anyone to believe anything on insufficient evidence.
—W. K. Clifford (1879, p. 186)
British philosopher and mathematician W. K. Clifford’s claim—that it is unethical to believe anything if you do not have sufficient evidence for it—elicited a pronounced response from the philosophical community. Many argued that Clifford’s claim was too strong and that it is acceptable to believe things for which we lack the requisite evidence. Whether or not one absolutely agrees with Clifford, he raises a good point. Every day, millions of people make decisions based on insufficient evidence. They claim that things are true or false without putting in the time, effort, and research necessary to make those claims with justification.
You have probably witnessed an argument in which people continue to make the same claims until they either begin to become upset or merely continue to restate their positions without adding anything new to the discussion. These situations often devolve and end with statements such as, “Well, I guess we will just agree to disagree” or “You are entitled to your opinion, and I am entitled to mine, and we will just have to leave it at that.” However, upon further reflection we have to ask ourselves, “Are people really entitled to have any opinion they want?”
From the perspective of critical thinking, the answer is no. Although people are legally entitled to their beliefs and opinions, it would be intellectually irresponsible of them to feel entitled to an opinion that is unsupported by logical reasoning and evidence; people making this claim are conflating freedom of speech with freedom of opinion. A simple example will illustrate this point. Suppose someone believes that the moon is composed of green cheese. Although he is legally entitled to his belief that the moon is made of green cheese, he is not rationally entitled to that belief, since there are many reasons to believe and much evidence to show that the moon is not composed of green cheese.
Good thinkers constantly question their beliefs and examine multiple sources of evidence to ensure their beliefs are true. Of course, people often hold beliefs that seem warranted but are later found not to be true, such as that the earth is flat, that it is acceptable to paint baby cribs with lead paint, and so on. However, a good thinker is one who is willing to change his or her views when those views are proved to be false. There are certain criteria that must be met for us to claim that someone is entitled to a specific opinion or position on an issue.
There are other examples where the distinction is not so clear. For instance, some people believe that women should be subservient to men. They hold this belief for many reasons, but the predominant one is because specific religions claim this is the case. Does the fact that a religious text claims that women should serve men provide sufficient evidence for one to believe this claim? Many people believe it does not. However, many who interpret their religious texts in this manner would claim that these texts do provide sufficient evidence for such claims.
It is here that we see the danger and difficulty of providing hard-and-fast definitions of what constitutes sufficient evidence. If we believe that written words in books came directly from divine sources, then we would be prone to give those words the highest credibility in terms of the strength of their evidence. However, if we view written words as arguments presented by their authors, then we would analyze the text based on the evidence and reasoning presented. In the latter case we would find that these people are wrong and that they are merely making claims based on their cultural, male-dominated environments.
Of course, all people have the freedom to believe what they want. However, if we think of entitlement as justification, then we cannot say that all people are entitled to their opinions and beliefs. As you read this book, think about what you believe and why. If you do not have reasons or supporting evidence for your beliefs and opinions, you should attempt to find it. Try not to get sucked into arguments without having evidence. Most important, as a good thinker, you should be willing and able to admit the strengths and weaknesses of various positions on issues, especially your own. At the same time, if in your search for evidence you find that the opposing position is the stronger one, you should be willing to change your position. It is also a sign of good thinking to suspend judgment when you suspect that the arguments of others are not supported by evidence or logical reasoning. Suspending judgment can protect you from error and making rash decisions that lead to negative outcomes.
Becoming a Critical Thinker
By now it should be clear that critical thinking is an important life skill, one that will have a decisive impact on our lives. It does not take luck or a genetic disposition to be a critical thinker. Anyone can master critical thinking skills. So how do you become a critical thinker? Earlier in the chapter, logical reasoning was described as the main tool for critical thinking. Thus, the most fundamental step in becoming a critical thinker is to recognize the importance of reason as the filter for your beliefs and actions. Once you have done this, you will be in the right frame of mind to start learning about logic and identify what tools of logic are at your disposal.
It is also important to note that becoming a critical thinker demands intellectual modesty. We can understand intellectual modesty as the willingness to put our egos in check because we see truth seeking as a far greater and more satisfying good than seeking to be right. Critical thinkers do not care about seeking approval by trying to show that they are right. They do not assume that disagreement reflects a lack of intelligence or insight. Being intellectually modest means recognizing not only that we can make mistakes, but also that we have much to learn. If we are (a) aware that we are bound to make mistakes and that we will benefit when we recognize them; (b) willing to break old habits and embrace change; and, perhaps most importantly, (c) genuinely willing to know what others think, then we can be truly free to experience life as richly and satisfactorily as a human being can.
1.2 Three Misconceptions About Logic
If logic is so important to critical thinking, we must of course examine what logic is. This task is not as easy as it sounds, and before we tackle it we must first dismantle some common misconceptions about the subject.
Logic Is for Robots
The first misconception is that it is not normal for humans to display a command of logic. (In fact, some suggest that humans created, rather than discovered, these patterns of thought; see A Closer Look: Logic: A Human Invention?) Think of how popular culture and media often depict characters endowed with logical reasoning. In American slang they are the eggheads, the geeks, the nerds, the ones who can use their minds but have trouble relating to other people. Such people often lack compassion or social charisma, or they are emotionally unexpressive. They are only logical and lack the blend of attributes that people actually have.
Consider the logically endowed characters on the Star Trek series. Vulcans, for example, are beings who suppress all emotions in favor of logic because they believe that emotions are dangerous. What appear to be heartless decisions by the Vulcans no doubt make logic seem quite unsavory to some viewers. The android Data—from The Next Generation series in the Star Trek franchise—is another example. Data’s positronic brain is devoid of any emotional capacity and thus processes all information exclusively by means of a logical calculus. Logic is thus presented as a source of alienation, as Data yearns for the affective depth that his human colleagues experience, such as humor and love.
Such presentations of logic as the polar opposite of emotion are false dichotomies because all human beings are naturally endowed with both logical and emotional faculties—not just one or the other. In other words, we have a broader range of abilities than that for which we give ourselves credit. So if you think that you are mostly emotional, then you simply have yet to discover your logical side.
Nonetheless, some believe emotions are the fundamental mark of human beings. It is quite likely that emotion has played a significant role in our survival as a species. Neuroscientists, for example, have discovered that our emotions have a faster pathway to the action centers of the brain than the methodical decision-making approach of our logical faculties (LeDoux, 1986, 1992). It pays, for example, to give no thought to running if we fear we are being hunted by a predator.
In most human civilizations today, however, dodging predators is not a main necessity. In fact, methodical reasoning is more advantageous in most of today’s situations. Thinking things through logically assists learning at all levels, produces better results in the job market (in seeking jobs, obtaining promotions, and procuring raises), and helps us make better choices. As noted in the previous section, we are more likely to be satisfied and experience fewer regrets if we reason carefully about our most critical choices in life. Indeed, logical reasoning can prove to be a better strategy for attaining the individual quest for personal fulfillment than any available alternative such as random choice, emotional impulse, waiting and seeing, and so on.
Moral of the Story: Emotions Versus Logic
Embracing logical reasoning does not mean disregarding our emotions altogether. Instead, we should recognize that emotions and logic are both essential components of what it is to be human.
A Closer Look: Logic: A Human Invention?
Aristotle’s Organon is a compilation of six treatises in which Aristotle formulated principles that laid the foundation for the field of logic.
One objection to the use of logic—often from what is known as a postmodern perspective—is that logic is a human invention and thus inferior to emotions or intuitions. In other words, what some call the “rules of logic” cannot be seen as universally applicable because logic originated in the Western world; thus, logic is relative and only a matter of perspective.
For example, the invention of chairs seems indispensable to those of us who live where chairs have become part of our cultural background. But those from different cultural backgrounds or those who lived during different time periods may not use chairs at all, or may employ alternative seating devices, such as the traditional Japanese tatami mats. To broadly apply the concept of chair as an appropriate place to sit would be ethnocentric, or applying the standards of one’s own culture to all other cultures.
In response to the foregoing objection, the authors of this text argue that logic is not a human invention, nor a convention that spread in certain parts of the world. Rather, logic was discovered in people’s ordinary encounters with reality, as early as antiquity. Based on available historical records, the first study of the principles at work in good reasoning emerged in ancient Greece. Aristotle was the first to formulate principles of logic, and he did so in six treatises that ancient commentators grouped together under the title Organon, which means “instrument” (reflecting the view that logic is the fundamental instrument for philosophy, which will be discussed later in the chapter).
Importantly, other civilizations have developed logic independently of the Greek tradition. For example, Dignaga was an important thinker in India who lived a few hundred years after Aristotle. Dignaga’s work begins with certain practices of debate within the Nyaya school of Hinduism and transitions to a more formal approach to reasoning. Although the result of Dignaga’s studies is not identical to Aristotle’s, there is enough similarity to strongly suggest that basic logical principles are not merely cultural artifacts.
In the Middle Ages, Aristotelian logic was brought to the West by Islamic philosophers and thus became part of the scholarship of Christian philosophers until the 14th or 15th century. The emergence of modern logic did not take place until the 19th and 20th centuries, during which new ways of analyzing propositions gave rise to new discoveries concerning the foundations of mathematics, as well as a new system of logical notation and a new system of logical principles that replaced the Aristotelian system.
Thus, the examination of good reasoning was fundamental in the development of human civilization. Logical reasoning has helped us to identify the laws that guide physical phenomena, which brought us to the state of technological advancement that we experience today. How else could we have erected pyramids and other marvels in the ancient world without having discovered a principle for checking the accuracy of the geometry employed to design them?
Logic Does Not Need to Be Learned
A second misconception is that logic does not need to be learned. After all, humankind’s unique distinction among other animals is the faculty of rationality and abstract thought. Although many nonhuman animals have very high levels of intelligence, to the best of our knowledge, abstract thought seems to be the mark of humankind’s particular brand of rationality. Today the applications of logical reasoning are all around us. We are able to experience air travel and marvel at rockets in space. We are also able to enjoy cars, skyscrapers, computers, cell phones, air-conditioning, home insulation, and even smart homes that allow users to regulate light, temperature, and other functions remotely via smartphones and other devices. Logical reasoning has afforded us an increasingly better picture of reality, and as a result, our lives have become more comfortable.
However, if logical reasoning is a natural human trait, then why should anyone have to learn it? We certainly experience emotions without any need to be trained, so why would the case be different with our rational capacities? Consider the difference between natural capacities that are nonvoluntary or automatic, on the one hand, and natural capacities that involve our will, on the other. Swallowing, digesting, and breathing are nonvoluntary natural capacities, as are emotions. We usually do not will ourselves to feel happy, angry, or excited. Rather, we usually just find ourselves feeling happy, angry, or excited.
Now contrast these with voluntary natural capacities such as walking, running, or sitting. We usually need to will these actions in order for them to take place. We do not just find ourselves running without intending to run, as is the case with swallowing, breathing, or feeling excited or angry. If logic were akin to breathing, the world would likely look like a different place.
Logic is practiced with intention and must be learned, just like we learn to walk, sit, and run. True, almost everyone learns to run to some degree as part of the normal process of growing up. Similarly, almost everyone learns a certain amount of logical reasoning as they move from infant to adult. However, to be a good runner, you need to learn and practice specific skills. Similarly, although everyone has some ability in logic, becoming a good critical thinker requires learning and practicing a range of logical skills.
Moral of the Story: Logic as a Skill
Having a natural capacity for something does not amount to being good at it. Even as emotions seem to come so naturally, some people have to work at being less sensitive or more empathetic. The same is true for logical reasoning.
Logic Is Too Hard
The final misconception is that logic is too hard or difficult to learn. If you have survived all these years without studying logic, you might wonder why you should learn it now. It is true that learning logic can be challenging and that it takes time and effort before it feels like second nature. But consider that we face the same challenge whenever we learn anything new, whether it is baking, automotive repair, or astrophysics. These are all areas of human knowledge that have a specific terminology and methodology, and you cannot expect to know how to bake a soufflé, fix a valve cap leak, or explain black holes without any investment in learning the subject matter.
Let us return to our running analogy. Just as we must intend to run in order to do it, we must intend to think methodically in order to do it. When we become adept at running, we do not have to put in as much effort or thought. A fit body can perform physical tasks more easily than an unfit one. The mind is no different. A mind accustomed to logical reasoning will find activities of the intellect easier than an unfit one. The best part is that if you wish to achieve logical fitness, all you need to do is learn and practice the necessary tools for it. The purpose of this book is to guide you toward this goal.
Without a doubt, learning logic will be challenging. But keep in mind that starting a logical fitness program is very much like starting a physical fitness program: There will be a little pain in the beginning. When out-of-shape muscles are exercised, they hurt. You might find that some lessons or concepts might give you a bit of trouble. When this happens, don’t give up! In a physical fitness program, we know that if we keep going, over time the pain goes away, the muscles get in shape, and movement becomes joyful. Likewise, as you keep working diligently on learning and developing your natural logical abilities, you will discover that you understand new things more easily, reading is less of a struggle for you, and logical reasoning is actually fun and rewarding. Eventually, you will begin to recognize logical connections (or the lack thereof) that you did not previously notice, make decisions that you are less likely to regret, and develop the confidence to defend the positions you hold in a way that is less emotionally taxing.
1.3 What Is Logic?
Having dispelled some common misconceptions, we can now occupy ourselves with a fundamental question for this book: What is logic? A first attempt to define logic might be to say that it is the study of the methods and principles of good reasoning. This definition implies that there are certain principles at work in good reasoning and that certain methods have been developed to encourage it. It is important to clarify that these principles and methods are not a matter of opinion. They apply to someone in your hometown as much as to someone in the smallest village on the other side of the world. Furthermore, they are as suitable today as they were 200 or 2,000 years ago.
This definition is a good place to start, but it leaves open the questions of what we mean by “good reasoning” and what makes some reasoning good relative to others. Although it is admittedly difficult to cram answers to all possible questions into a pithy statement, definitions should attempt to be more specific. In this book, we shall employ the following definition: Logic is the study of arguments that serve as tools for arriving at warranted judgments. Notice that this definition states how logic can be of service to you now, in your daily routine, and in whatever occupation you hold. To understand how this is the case, let us unpack this definition a bit.
The Study of Arguments
In logic, an argument is the methodical presentation of one’s position on a topic, not a heated fight with another person.
This definition of logic does not explain that there are principles at work in good reasoning or that these principles are not necessarily informed by experience: The meaning of the word argument in logic does the job. Argument has a very technical meaning in logic, and for this reason, Chapter 2 is dedicated entirely to the definition of arguments—what they are, what they are not, what they consist of, and what makes them good. Later in this chapter, we will survey other meanings for the word argument outside of logic.
For now, let us refer to an argument as a methodical defense of a position. Suppose that Diana is against a proposed increase in the tax rate. She decides to write a letter to the editor to present her reasons why a tax increase would be detrimental to all. She researches the subject, including what economists have to say about tax increases and the position of the opposition. She then writes an informed defense of her position. By advancing a methodical defense of a position, Diana has prepared an argument.
A Tool for Arriving at Warranted Judgments
For our purposes, the word judgment refers simply to an informed evaluation. You examine the evidence with the goal of verifying that if it is not factual, it is at least probable or theoretically conceivable. When you make a judgment, you are determining whether you think something is true or false, good or bad, right or wrong, beautiful or ugly, real or fake, delicious or disgusting, fun or boring, and so on. It is by means of judgments that we furnish our world of beliefs. The richer our world of beliefs, the clearer we can be about what makes us happy. Judgments are thus very important, so we need to make sure they are sound.
What about the word warrant? Why are warranted judgments preferable to unwarranted ones? What is a warrant? If you are familiar with the criminal justice system or television crime dramas, you may know that a warrant is an authoritative document that permits the search and seizure of potential evidence or the arrest of a person believed to have committed a crime. Without a warrant, such search and seizure, as well as coercing an individual to submit to interrogation or imprisonment, is a violation of the protections and rights that individuals in free societies enjoy. The warrant certifies that the search or arrest of a person is justified—that there is sufficient reason or evidence to show that the search or arrest does not unduly violate the person’s rights. More generally, we say that an action is warranted if it is based on adequate reason or evidence.
Accordingly, our judgments are warranted when there is adequate reason or evidence for making them. In contrast, when we speak of something being unwarranted, we mean that it lacks adequate reason or evidence. For example, unwarranted fears are fears we have without good reason. Children may have unwarranted fears of monsters under their beds. They are afraid of the monsters, but they do not have any real evidence that the monsters are there. Our judgments are unwarranted when, like a child’s belief in lurking monsters under the bed, there is little evidence that they are actually true.
In the criminal justice system, the move from suspicion to arrest must be warranted. Similarly, in logic, the move from grounds to judgment must be warranted (see A Closer Look: Warrants for the Belief in God for an example). We want our judgments to be more like a properly executed search warrant than a child’s fear of monsters. If we fail to consider the grounds for our judgments, then we are risking our lives by means of blind decisions; our judgments are no more likely to give us true beliefs than false ones. It is thus essential to master the tools for arriving at warranted judgments.
It is important to recognize the urgency for obtaining such mastery. It is not merely another nice thing to add to the bucket list—something we will get around to doing, right after we trek to the Himalayas. Rather, mastering the argument—the fundamental tool for arriving at warranted judgments—is as essential as learning to read and write. Knowledge of logic is a relatively tiny morsel of information compared to all that you know thus far, but it has the capacity to change your life for the better.
A Closer Look: Warrants for the Belief in God
In his Summa Theologica, Thomas Aquinas advanced the idea that belief in the existence of God can be grounded in logical argument.
Striving for warranted judgments might seem difficult when it comes to beliefs that we have accepted on faith. Note that not all that we accept on faith is necessarily related to God or religion. For example, we likely have faith that the sun will rise tomorrow, that our spouses are honest with us, and that the car we parked at the mall will still be there when we return from shopping. Many American children have faith that the tooth fairy will exchange money for baby teeth and that Santa Claus will bring toys come Christmas. Are we reasoning correctly by judging such beliefs as warranted? Whatever your answer in regard to these other issues, questions of religious belief are more likely to be held up as beyond the reach of logic. It is important to recognize this idea is far from being obviously true. Many deeply religious people have nonetheless found it advisable to offer arguments in support of their beliefs.
One such individual was Thomas Aquinas, a 13th-century Roman Catholic Dominican priest and philosopher. In his Summa Theologica (Aquinas, 1947), he advanced five logical arguments for God’s existence that do not depend on faith.
The 20th-century Oxford scholar and Christian apologist C. S. Lewis, perhaps best known for the popular children’s series The Chronicles of Narnia, did not embrace his Anglican religion until he was in his thirties. In his books Mere Christianity and Miracles: A Preliminary Study, he employs reason to defend Christian beliefs and the logical possibility of miracles.
There are, of course, many more examples. The important point to draw from this is that all of our judgments of faith—from the faith in the sun rising tomorrow to the faith in the existence of God—should be warranted beliefs and not just beliefs that we readily accept without question. In other words, even faith should make sense in order to be able to communicate such beliefs to those who do not share those beliefs. Note that philosophers who have presented arguments in defense of their religious views have helped transform the nature of religious disagreement to one in which the differences are generally debated in an intellectually enlightening way.
We have not yet reached the point in which differences in religious views are no longer the cause of wars or killing. Nonetheless, the power of argument in the formation of our beliefs is that it supports social harmony despite diversity and disagreement in views, and we all gain from presenting our unique positions in debated issues.
Formal Versus Informal Logic
Logic is a rich and complex field. Our focus here will be how logic contributes to the development and honing of critical thinking in everyday life. Primarily, the concepts we will discuss will reflect principles of informal logic. The principal aim in informal logic is to examine the reasoning we employ in the ordinary and everyday claims we make.
In contrast, formal logic is far more abstract, often involving the use of symbols and mathematics to analyze arguments. Although this text will touch on a few formal concepts of logic in its discussions of deduction (see Chapter 3 and Chapter 4), the purpose in doing so is to develop methodology for good reasoning that is directly applicable to ordinary life.
1.4 Arguments Outside of Logic
Although Chapter 2 will explore the term argument in more detail, it is important to clarify that the word is not exclusive to logic. Its meaning varies widely, and you may find that one of the descriptions in this section fits your own understanding of what is an argument. Knowing there is more than one meaning of this word, depending on context or application, will help you correctly understand what is meant in a given situation.
Arguments in Ordinary Language
Often, we apply the word argument to an exchange of diverging views, sometimes in a heated, angry, or hostile setting. Suppose you have a friend named Lola, and she tells you, “I had an argument with a colleague at work.” In an ordinary setting you might be correct in understanding Lola’s meaning of the term argument as equivalent to a verbal dispute. In logic, however, an argument does not refer to a fight or an angry dispute. Moreover, in logic an argument does not involve an exchange between two people, and it does not necessarily have an emotional context.
Although in ordinary language an argument requires that at least two or more people be involved in an exchange, this is not the case in logic. A logical argument is typically advanced by only one person, either on his or her behalf or as the representative of a group. No exchange is required. Although an argument may be presented as an objection to another person’s point of view, there need not be an actual exchange of opposing ideas as a result.
Now, if two persons coordinate a presentation of their defenses of what can be identified as opposing points of view, then we have a debate. A debate may contain several arguments but is not itself an argument. Accordingly, only debates are exchanges of diverging views.
Even if a logical argument is both well supported and heartfelt, its emotional context is not its driving force. Rather, any emotion that may be inevitably tied in with the defense of the argument’s principal claim is secondary to the reasons advanced. But let us add a little contextual reference to the matter of debates. If the arguments on each side of the debate are presented well, then the debate may lead to the discovery of perspectives that each party had not previously considered. As such, debates can be quite enlightening because every time our own perspective is broadened with ideas not previously considered and that are well supported and defended, it is very difficult for the experience to be negative. Instead, a good debate is an intellectually exhilarating experience, regardless of how attached one may be to the side one is defending.
Not even debates need to be carried out with an angry or hostile demeanor, or as a means to vent one’s frustration or other emotions toward the opposition. To surrender to one’s emotions in the midst of a debate can cause one to lose track of the opposition’s objections and, consequently, be able to muster only weak rebuttals.
Moral of the Story: Defining the Word Argument
To avoid conflating the two widely different uses of the word argument (that is, as a dispute in ordinary language and as a defense of a point of view in logic) is to use the word only in its classical sense. In its classical meaning, an argument does not refer to a vehicle to express emotions, complaints, insults, or provocations. For these and all other related meanings, there are a wide variety of terms that would do a better job, such as disagreement, quarrel, bicker, squabble, fight, brawl, altercation, having words, insult match, word combat, and so on. The more precise we are in our selection of words, the more efficient our communications.
Rhetorical Arguments
Think about how politicians might try to persuade you to vote for them. They may appeal to your patriotism. They may suggest that if the other candidate wins, things will go badly. They may choose words and examples that help specific audiences feel like the politician empathizes with their situation. All of these techniques can be effective, and all are part of what someone who studies rhetoric—the art of persuasion—might include under the term argument.
Rhetoric is a field that uses the word argument almost as much as logic does. You are likely to encounter this use in English, communication, composition, or argumentation classes. From the point of view of rhetoric, an argument is an attempt to persuade—to change someone’s opinion or behavior. Because the goal of a rhetorical argument is persuasion, good arguments are those that are persuasive. In fact, any time someone attempts to persuade you to do something, they can be seen as advancing an argument in this sense.
Think about how you might have persuaded a sibling to do something for you when you were young. You might have offered money, tried to manipulate with guilt-inducing tactics, appealed to his or her sense of pride or duty, or just attempted to reason with him or her. All of these things can be motivating, and all may be part of a rhetorical approach to arguments. However, while getting someone to do something out of greed, guilt, pride, or pity can indeed get you what you want, this does not mean you have succeeded in achieving a justified defense of your position.
Some of the most impressive orators in history—Demosthenes, Cicero, Winston Churchill—were most likely born with a natural talent for rhetoric, yet they groomed their talent by becoming well educated and studying the speeches of previous great orators. Rhetoric depends not only on the mastery of a language and broad knowledge, but also on the fine-tuning of the use of phrases, metaphors, pauses, crescendos, humor, and other devices. However, a talent for rhetoric can be easily employed by unscrupulous people to manipulate others. This characteristic is precisely what distinguishes rhetorical arguments from arguments in logic.
Whereas rhetorical arguments aim to persuade (often with the intent to manipulate), logical arguments aim to demonstrate. The distinction between persuading and demonstrating is crucial. Persuading requires only the appearance of a strong position, perhaps camouflaged by a strong dose of emotional appeal. But demonstrating requires presenting a position in a way that may be conceivable even by opponents of the position. To achieve this, the argument must be well informed, supported by facts, and free from flawed reasoning. Of course, an argument can be persuasive (meaning, emotionally appealing) in addition to being logically strong. The important thing to remember is that the fundamental end of logical arguments is not to persuade but to employ good reasoning in order to demonstrate truths.
Moral of the Story: Persuasion Versus Demonstration
Purely persuasive arguments are undoubtedly easier to advance, which makes them the perfect tool for manipulation and deceit. However, only arguments that demonstrate with logic serve the end of pursuing truth; thus, they are the preferable ones to master.
Revisiting Arguments in Logic
Suppose you and your friend watch a political debate, and she tells you that she thought one of the candidates gave a good argument about taxes. You respond that you thought the candidate’s argument was not good. Have you disagreed with each other? You might think that you had, but you may just be speaking past each other, using the term argument in different senses. Your friend may mean that she found the argument persuasive, while you mean that the argument did not establish that the candidate’s position was true. It may turn out that you both agree on these points. Perhaps the candidate gave a rousing call to action regarding tax reform but did not spend much time spelling out the details of his position or how it would work to solve any problems. In this sort of case, the candidate may have given a good argument in the rhetorical sense but a bad argument in the logical sense.
To summarize:
In contrast to ordinary arguments, logical arguments do not involve an exchange of any kind.
In contrast to ordinary arguments and rhetorical arguments, logical arguments are not driven by emotions. In logic, only the reasons provided in defense of the conclusion make up the force of the argument.
In contrast to rhetorical arguments, logical arguments are not primarily attempts to persuade, because there is no attempt to appeal to emotions. Rather, logical arguments attempt only to demonstrate with reasons. Of course, good logical arguments may indeed be persuasive, but persuasion is not the primary goal.
The goal of an argument in logic is to demonstrate that a position is likely to be true.
So before you go on to have a quarrel with your friend, make sure you are both using the word in the same way. Only then can you examine which sense of argument is the most crucial to the problem raised. Should we vote for a candidate who can get us excited about important issues but does not tell us how he or she proposes to solve them? Or shall we vote for a candidate who may not get us very excited but who clearly outlines how he or she is planning to solve the nation’s problems?
In the rest of this book, you should read the word argument in the logical sense and no other. If the word is ever used in other ways, the meaning will be clearly indicated. Furthermore, outside of discussions of logic, you must clarify how the word is being used.
1.5 The Importance of Language in Logic
The foregoing distinction of the different uses and meanings of the word argument show the importance of employing language precisely. In addition to creating misunderstandings, misused words or the lack of knowledge of distinctions in meaning also prevent us from formulating clear positions about matters that pertain to our personal goals and happiness. Language affects how we think, what we experience, how we experience it, and the kind of lives we lead.
Language is our most efficient means of communicating what is in our minds. However, it is not the only means by which humans communicate. We also communicate via facial expressions, gestures, and emotions. However, these nonverbal cues often need clarifying words so we can clearly grasp what someone else is expressing or feeling, especially people we don’t know very well. If we see a stranger crying, for example, we might not be able to distinguish at first glance if the tears are from happiness or sadness. If we are visiting a foreign land and hear a man speaking in a loud voice and gesturing wildly, we might not know if he is quarrelling or just very enthusiastic unless we understand his language.
This suggests that words matter very much because they are the universal means for making ourselves clear to others. This may seem obvious, since we all use language to communicate and, generally speaking, seem to manage satisfactorily. What we do not often recognize, however, is the difference we could experience if we took full advantage of clear and precise language in its optimal form. One result could be that many will no longer ignore what we say. Another could be that as our vocabulary expands, we will no longer be limited to what we can express to others or in what we can grasp from our experiences.
Suppose, for example, that you are invited to a dinner that unbeknownst to you introduces you to a spice you have never tasted before. As you savor the food on your plate, you may taste something unfamiliar, but the new flavor may be too faint for you, amidst the otherwise familiar flavors of the dish you are consuming. In fact, you may be cognitively unaware of the character of this new flavor because you are unable to identify it by name and, thus, as a new flavor category in your experience.
Hume’s essay Of the Standard of Taste stated that taste depends on the refinement of sensory properties, but recent neurobiological research suggests that taste may actually be dependent on language.
According to philosopher David Hume (1757), many of us do not have a sensitive enough palate to actually recognize new or unfamiliar flavors in familiar taste experiences. For those who do, it would seem that the test of a sensitive palate lies not with strong flavors but with faint ones. However, recent neurobiological research suggests that our responses to taste are not entirely dependent on the refinement of our sensory properties but, rather, on higher levels of linguistic processing (Grabenhorst, Rolls, & Bilderbeck, 2008). In other words, if you cannot describe it, it may be quite possible you are unable to taste it; our ability to skillfully use language thus improves our experience.
Logicians and philosophers in general take language very seriously because it is the best means for expressing our thoughts, to be understood by others, and to clarify ideas that are in need of clarification. Communicating in a language, however, is more complex than we recognize. As renowned philosopher John Searle observed, “Speaking a language is engaging in a rule-governed form of behavior” (Searle, 1969, p. 22). This means that whenever we talk or write, we are performing according to specific rules. Pauses in speech are represented by punctuation marks such as commas or periods. If we do not pause, the meaning of the same string of words could change its meaning completely. The same principle applies in writing. But although we are more conscious of making such pauses in speech, sometimes we overlook their importance in writing. A clever saying on a T-shirt illustrates this point, and it reads as follows:
Let’s eat Grandma.
Let’s eat, Grandma.
Commas save lives.
Indeed, even what may seem like a meaningless little comma can dramatically change the meaning of a sentence. If we want to make sure others understand our written meaning, we need to be mindful of relevant punctuation, grammatical correctness, and proper spelling. If something is difficult to read because the grammar is faulty, punctuation is missing, or the words are misspelled, these obstacles will betray the writer’s meaning.
Moral of the Story: The Importance of Language in Logic
Clarity, precision, and correctness in language are not only important to the practical quest of communicating your ideas to others; they are fundamental to the practice of logical reasoning.
1.6 Logic and Philosophy
By this point, you may have noticed that logic and philosophy are often mentioned together. There is good reason for this. Logic is not only an area of philosophy but also its bread and butter. It is important to understand the connection between these two fields because understanding the pursuit of philosophy will help clarify in your mind the value of logic in your life.
First, however, let us confront the elephant in the room. Some people have no idea what philosophers do. Others think that philosophers simply spend time thinking about things that have little practical use. The stereotypical image of a philosopher, for instance, is a bearded man asking himself: “If a tree falls in the forest and there is no one else to hear it, is there sound?” Your response to this may be: “Why should anyone care?” The fact is that many do, and not only bearded philosophers: Such a question is also critical to those who work at the boundaries of philosophy and science, as well as scientists who investigate the nature of sound, such as physicists, researchers in medicine and therapy, and those in the industry of sound technology.
Spatial views regarding sound, for example, have given rise to three theories: (a) sound is where there is a hearer, (b) sound is in the medium between the resonating sound and the hearer, and (c) sound is at the resonating object (Casati & Dokic, 2014). Accordingly, the tree in the forest question would have the following three corresponding answers: (a) no, if sound is where there is a hearer; (b) no, if sound is in the medium between the resonating sound and a hearer; and (c) yes, if sound is located in the resonating object such as a human ear. This seemingly impractical question, as it turns out, is not only quite interesting but also bears tangible results that lead to our better understanding of acoustics, hearing impairments, and sound technology. The best part is that the results affect us all. Many modern technologies arose from a “tree in the forest” examination.
Children’s inquisitive nature personifies the act of being philosophical. Asking questions to clarify ideas or seek the truth is fundamental to engaging in philosophy.
The Goal of Philosophy
Now that the practical nature of philosophical inquiry has been demonstrated, we can move to a more fruitful examination of what exactly philosophy is. In one view, philosophy is the activity of clarifying ideas. It is an activity because philosophy is not fundamentally a body of knowledge (as is history or biology, for example) but rather an activity. The goal of philosophical activity is to clarify ideas in the quest for truth.
How does one clarify ideas? By asking questions—especially “why?,” “what does that mean?,” and “what do you mean?” Philosophers have observed that asking such questions may be a natural human inclination. Consider any 2-year-old. As he or she begins to command the use of language, the child’s quest seems to be an attempt to understand the world by identifying what things are called. This may be annoying to some adults, but if we understand this activity as philosophical, the child’s goal is clear: Names are associated with meanings, and this process of making distinctions and comparisons of similarity is essentially the philosophical mechanism for learning (Sokolowski, 1998).
Once we name things, we can distinguish things that are similar because names help us separate things that appear alike. To a 2-year-old, a toy car and a toy truck may appear similar—both are vehicles, for example, and have four tires—but their different names reflect that there are also differences between them. So a 2-year-old will most likely go on to ask questions such as why a car is not the same as a truck until she grasps the fundamental differences between these two things. This is the truth-seeking nature of philosophy.
Philosophy and Logical Reasoning
Logic and the Pursuit of Truth
Like philosophy, logic seeks to discover the truth of our conceptions.
Critical Thinking Questions
It is stated that logic brings clarity to our conceptions of the world. Is it possible that through studying logic and applying it to your daily life, some of your long-standing beliefs might shift once you apply the principles of logic?
What is the distinction between logic and critical thinking? Are they fundamentally the same? Is logic just a systematic form of critical thinking?
Since children’s natural learning state is a philosophical attitude, by the time we start elementary school, we already have a few years of philosophical thinking under our belt. Unfortunately, the philosophical attitude is not always sustained beyond this point. Over time, we stop clarifying ideas because we might get discouraged from asking or we just get tired or complacent. We then begin to accept everything that we are told or shown by those around us, including what we watch on television or learn through social media. Once we stop filtering what we accept by means of questions, as we did when we were very small children, we become vulnerable to manipulation and deceit.
When we stop using questions to rationally discern among alternatives or to make judgments concerning disputed social problems, we begin to rely entirely on emotions or on past experience as the basis for our decisions and judgments. As discussed earlier in the chapter, although emotions are valid and worthwhile, they can also be unreliable or lead us to make rash decisions. This may be somewhat inconsequential if we are simply buying something on impulse at the mall. But if we make judgments based purely on fear or anger, then emotions have much more dire consequences, perhaps causing us to mistreat or discriminate against others.
Past experience can also be misleading. Consider Jay, a university student, who has done very well in his first four university courses. He has found the courses relatively easy and not very demanding, so he assumes that all university courses are easy. He is then surprised when he discovers that Introduction to Physics is a challenging course, when he should have rationally recognized that undertaking a university education is a challenging task. Asking himself questions about the past courses—subject matter, professor, and so on—may help Jay adjust his expectations.
Let us review two important points that we have discussed so far. First, philosophy is an activity of clarifying ideas. Second, the goal of philosophy is to seek truth about all phenomena in our experience. Logic provides us with an effective method for undertaking the task of philosophy and discovering truths. This view has thus remained mainstream in Western philosophy. When we think philosophically with regard to our mundane practical purposes, logic offers us the tools to break the habit of relying on our emotions, feelings, or our past experiences exclusively for making our decisions. Arriving at this recognition alone in your own case will be part and parcel of your journey, with this book as your guide.
Chapter 2
2.1 Arguments in Logic
Chapter 1 provisionally defined argument as a methodical defense of a position. We referred to this as the commonsense understanding of the way the word argument is employed in logic. The commonsense definition is very useful in helping us recognize a unique form of expression in ordinary human communication. It is part of the human condition to differ in opinion with another person and, in response, to attempt to change that person’s opinion. We may attempt, for example, to provide good reasons for seeing a particular movie or to show that our preferred kind of music is the best. Or we may try to show others that smoking or heavy drinking is harmful. As you will see, these are all arguments in the commonsense understanding of the term.
In Chapter 1 we also distinguished the commonsense understanding of argument from the meaning of argument in ordinary use. Arguments in ordinary use require an exchange between at least two people. As clarified in Chapter 1, commonsense arguments do not necessarily involve a dialogue and therefore do not involve an exchange. In fact, one could develop a methodical defense of a position—that is, a commonsense argument—in solitude, simply to examine what it would require to advocate for a particular position. In contrast, arguments, as understood in ordinary use, are characterized by verbal disputes between two or more people and often contain emotional outbursts. Commonsense arguments are not characterized by emotional outbursts, since unbridled emotions present an enormous handicap for the development of a methodical defense of a position.
In logic an argument is a set of claims in which some, called the premises, serve as support for another claim, called the conclusion. The conclusion is the argument’s main claim. For the most part, this technical definition of argument is what we shall employ in the remainder of this book, though we may use the commonsense definition when talking about less technical examples. Table 2.1 should help clarify which meanings are acceptable within logic. Take a moment to review the table and fix these definitions in your mind.
Table 2.1: Comparing meanings for the term argument
Meaning in ordinary use
Commonsense meaning
Technical meaning in logic
A verbal quarrel or disagreement, often characterized by raised voices and flaring emotions.
The methodical and well-researched defense of a position or point of view advanced in relation to a disputed issue.
A set of claims in which some, called premises, serve as support for another claim, called the conclusion.
Arguments in the technical sense are a primary way in which we can defend a position. Accordingly, we can find the structure of logical arguments in commonsense arguments all around us: in letters to the editor, social media, speeches, advertisements, sales pitches, proposals submitted for grant funds or bank loans, job applications, requests for a raise, communications of values to children, marriage proposals, and so on. Arguments often provide the basis on which most of our decisions are made. We read or hear an argument, and if we are convinced by it, then we accept its conclusion. For example, consider the following argument:
“I’m just not a math person.” We hear this all the time from anyone who found high school math challenging. . . . In high school math at least, inborn talent is less important than hard work, preparation, and self-confidence. This is what high school math teachers, college professors, and private tutors have observed as the pattern of those who become good in high school math. They point out that in any given class, students fall in a wide range of levels of math preparation. This is not due to genetic predisposition. What is rarely observed is that some children come from households in which parents introduce them to math early on and encourage them to practice it. These students will immediately obtain perfect scores while the rest do not. As a result, the students without previous preparation in math immediately assume that those with perfect scores have a natural math talent, without knowing about the preparation that these students had in their homes. In turn, the students who obtain perfect scores assume that they have a natural math talent given their scores relative to the rest of the class, so they are motivated to continue honing their math skills and, by doing this, they cement their top of the class standing. Thus, the belief that math ability cannot change becomes a self-fulfilling prophecy. (Kimball & Smith, 2013)
In this argument, the position defended by the authors is that the belief that math ability cannot change becomes a self-fulfilling prophecy. The authors support this claim with reasons that show good performance in math is not typically the result of a natural ability but of having a family support system for learning, a prior preparation in math from home, and continuous practice. It makes the case that it is hard work and preparation that lead to a person’s proficiency in math and other subjects, not genetic predisposition. This argument helps us recognize that we frequently accept oft-repeated information as fact without even questioning the basis. As you can see, an argument such as this can provide a solid basis for our everyday decisions, such as encouraging our children to work hard and practice in the subjects they find most difficult or deciding to obtain a university degree with confidence later in life.
To understand the more technical definition of an argument as a set of premises that support a conclusion, consider the following presentation of the reasoning from the commonsense argument we have just examined.
Good performance in math is not due to genetics.
Good performance in math only requires preparation and continuous practice.
Students who do well initially assume they have natural talent and practice more.
Students who do less well initially assume they do not have natural talent and practice less.
Therefore, believing that one’s math ability cannot change becomes a self-fulfilling prophecy.
Presenting the reasoning this way can do a great deal to clarify the argument and allow us to examine its central claims and reasoning. This is why the field of logic adopts the more technical definition of argument for much of its work.
Regardless of what we think about math, an important contribution of this argument is that it makes the case that it is hard work and preparation that lead to our proficiency in math, and not the factor of genetic predisposition. Logic is much the same way. If you find some concepts difficult, don’t assume that you just lack talent and that you aren’t a “logic person.” With practice and persistence, anyone can be a logic person.
On your way to becoming a logic person, it is important to remember that not everything that presents a point of view is an argument (see Table 2.2 for examples of arguments and non-arguments). Consider that when one expresses a complaint, command, or explanation, one is indeed expressing a point of view. However, none of these amount to an argument.
Claims
A claim is an assertion that something is or is not the case. Claims take the form of declarative sentences. It is important to note that each premise or conclusion consists of one single claim. In other words, each premise or conclusion consists of one single declarative sentence.
Claims can be either true or false. This means that if what is asserted is actually the case, then the claim is true. If the claim does not correspond to what is actually the case, then the claim is false. For example, the claim “milk is in the refrigerator” predicates that the subject of the claim, milk, is in the refrigerator. If this claim corresponds to the facts (if the refrigerator contains milk), then this claim is true. If it does not correspond to the facts (if the refrigerator does not contain milk), then the claim is false.
Not all claims, however, can be easily checked for truth or falsity. For example, the truth of the claim “Jacob has the best wife in the world” cannot be settled easily, even if Jacob is the one asserting this claim (“I have the best wife in the world”). In order to understand what he could possibly mean by “best wife in the world,” we would have to propose the criteria for what makes a good wife in the first place, and as if this were not challenging enough, we would then have to establish a method or procedure to make comparisons among good wives. Of course, Jacob could merely mean “I like being married to my wife,” in which case he is not stating a claim about his wife being the best in the world but merely stating a feeling. It is not uncommon to hear people state things that sound like claims but are actually just expressions of preference or affection, and distinguishing between these is often challenging because we are not always clear in the way we employ language. Nonetheless, it is important to note that we often make claims from a particular point of view, and these claims are different from factual claims. Claims that advance a point of view, such as the example of Jacob’s wife—and especially claims about morality and ethicality—are indeed more challenging to settle as true or false than factual claims, such as “The speed limit here is 55.”
The important point is that both kinds of claims—the factual claim and the point-of-view claim—assert that something is or is not the case, affirm or deny a particular predicate of a subject, and can be either true or false. The following sentences are examples of claims that meet these criteria.
There is a full moon tonight.
Pecans are better than peanuts.
All flights to Paris are full.
BMWs are expensive to maintain.
Lola is my sister.
The following are not claims:
Is it raining? Why? Because questions are not, and cannot be, assertions that something is the case.
Oh, to be in Paris in the springtime! Why? Because this expresses a sentiment but does not state that anything might be true or false.
Buy a BMW! Why? Because a command is not an assertion that something is the case.
We often intend to advance claims in ways that do not present our claims clearly and properly—for example, by means of rhetorical questions, vague expressions of affection, and commands or metaphors that demand interpretation. But it is important to recognize that intention is not sufficient when communicating with others. In order for our intended claims to be identified as claims, they should meet the three criteria previously mentioned.
Claims are sometimes called propositions. We will use the terms claims and propositions interchangeably in this book. In this chapter we will stick to the word claim, but in subsequent chapters, we will move to the more formal terminology of propositions.
The Standard Argument Form
In informal logic the main method for identifying, constructing, or examining arguments is to extract what we hear or read as arguments and put this in what is known as the standard argument form. It consists of claims, some of which are called premises and one of which is called the conclusion. In the standard argument form, premises are listed first, each on a separate line, with the conclusion on the line after the last premise. There are various methods for displaying standard form. Some methods number the premises; others separate the conclusion with a line. We will generally use the following method, prefacing the conclusion with the word therefore:
Premise
Premise
Therefore, Conclusion
The number of premises can be as few as one and as many as needed. We must approach either extreme with caution given that, on the one hand, a single premise can offer only very limited support for the conclusion, and on the other hand, many premises risk error or confusion. However, there are certain kinds of arguments that, because of their formal structure, may contain only a limited number of premises.
In the standard argument form, each premise or conclusion should be only one sentence long, and premises and conclusions should be stated as clearly and briefly as possible. Accordingly, we must avoid premises or conclusions that have multiple sentences or single sentences with multiple claims. The following example shows what not to do:
I live in Boston, and I like clam chowder.
My family also lives in Boston. They also like clam chowder.
My friends live in Boston. They all like clam chowder, too.
Therefore, everyone I know in Boston likes clam chowder.
If you want to make more than one claim about the same subject, then you can break your declarative sentences into several sentences that each contain only one claim. The clam chowder argument can then be rewritten as follows:
I live in Boston.
I like clam chowder.
My family lives in Boston.
My family likes clam chowder.
My friends live in Boston.
My friends like clam chowder.
Therefore, everyone I know in Boston likes clam chowder.
The relationship between premises and the conclusion is that of inference—the process of drawing a claim (the conclusion) from the reasons offered in the premises. The act of reasoning from the premises serves as the glue connecting the premises with the conclusion.
2.2 Putting Arguments in the Standard Form
Presenting arguments in the standard argument form is crucial because it provides us with a dispassionate method that will allow us to find out whether the argument is good, regardless of how we feel about the subject matter. The first step is to identify the fundamental argument being presented.
At first it might seem a bit daunting to identify an argument, because arguments typically do not come neatly presented in the standard argument form. Instead, they may come in confusing and unclear language, much like this statement by Special Prosecutor Francis Schmitz of Wisconsin regarding Governor Scott Walker:
Governor Walker was not a target of the investigation. At no time has he been served with a subpoena. . . . While these documents outlined the prosecutor’s legal theory, they did not establish the existence of a crime; rather, they were arguments in support of further investigation to determine if criminal charges against any person or entity are warranted. (Crocker, 2014, para. 7 & 10)
This was a position presented in regard to the investigation of an alleged illegal campaign finance coordination during the 2011–2012 recall elections (Stein, 2014). Does it claim a vindication of Walker? Or does it suggest that there may be sufficient evidence to make Walker a central figure in the investigation? How would you even begin to make heads or tails of such a confusing argument? Do not despair. The remainder of this section will show you exactly what to look for in order to make sense of the most complicated argument. With a little practice, you will be able to do this without much effort.
Find the Conclusion First
Punctuation, parentheses, and conclusion indicators all serve as signposts to assist us when deconstructing an argument. They provide important clues about where to find the conclusion as well as supporting claims.
Although the conclusion is last in the standard form, the conclusion is the first thing to find because the conclusion is the main claim in an argument. The other claims—the premises—are present for the sole purpose of supporting the conclusion. Accordingly, if you are able to find the conclusion, then you should be able to find the premises.
The good news is that language is not only a means for expressing ideas; it also offers a road map for the ideas presented. Chapter 1 underscored the fundamental importance of clear, precise, and correct language in logical reasoning. When used properly, language also offers structures and directions for communicating meaning, thus facilitating our understanding of what others are saying. One punctuation mark—the question mark—tells us that we are confronting a question. A different punctuation mark—the parentheses—tells us that we are being given relevant information but only as an aside or afterthought to the main point; if removed, the parenthetical information would not alter the main point. In the case of arguments, some words serve as signposts identifying conclusions. Take the following example of an argument in the standard argument form:
All men are mortal.
Socrates is a man.
Therefore, Socrates is mortal.
The word therefore indicates that the sentence is a conclusion. In fact, the word therefore is the standard conclusion indicator we will use when constructing arguments in the standard argument form. However, there are other conclusion indicators that are used in ordinary arguments, including:
Consequently . . .
So . . .
Hence . . .
Thus . . .
Wherefore . . .
As a result . . .
It follows that . . .
For these reasons . . .
We may conclude that . . .
When a conclusion indicator is present, it can help identify the conclusion in an argument. Unfortunately, many arguments do not come with conclusion indicators. In such cases start by trying to identify the main point. If you can clearly identify a single main point, then that is likely to be the conclusion. But sometimes you will have to look at a passage closely to find the conclusion. Suppose you encounter the following argument:
Don’t you know that driving without a seat belt is dangerous? Statistics show that you are 10 times more likely to be injured in an accident if you are not wearing one. Besides, in our state you can get fined $100 if you are caught not wearing one. You ought to wear one even if you are driving a short distance.
Arguments are often longer and more complicated than this one, but let us work with this simple case before trying more complicated examples. You know that the first thing you need to do is to look for the conclusion. The problem is that the author of the argument does not use a conclusion indicator. Now what? Nothing to worry about. Just remember that the conclusion is the main claim, so the thing to look for is what the author may be trying to defend. Although the first sentence is stated as a question—remember, punctuation marks give us important clues—the author seems to intend to assert that driving without a seat belt is dangerous. In fact, the second sentence offers evidence in support of this claim. On the other hand, the third sentence seems to be important, yet it does not speak to driving without a seat belt being dangerous, only expensive. In the final sentence, we find a claim that is supported by all the others. Because of this, the final sentence presents the conclusion.
Now, it so happens that in this case, the conclusion is at the end of this short argument, but keep in mind that conclusions can be found in various places in essays, such as the beginning or sometimes in the middle. Now that you have identified your first piece of the puzzle, we have this:
Premise 1: ?
Premise 2: ?
Premise 3: ?
Therefore, you ought to wear a seat belt whenever you drive.
You might have noticed that the conclusion does not appear as it did in the essay. The original sentence is “You ought to wear one even if you are driving a short distance.” Why did we modify it? Once again, clarity is of the essence in logical reasoning. Conclusions should make the subject clear, so the pronoun one was replaced with the actual subject to which the author is referring: seat belt. In addition, the predicate “even if you are driving a short distance” was rewritten to reflect the more inclusive point that the author seems to be making: that you should wear a seat belt whenever you drive.
This modification of language, known as paraphrasing, is part of the construction of arguments in the standard argument form. The act of extracting an argument from a longer piece to its fundamental claims in the standard argument form necessarily involves paraphrasing the original language to the clearest and most precise form possible. This concept will be addressed in greater detail later in this section.
Find the Premises Next
After identifying the conclusion, the next thing to do is look for the reasons the author offers in defense of his or her position. These are the premises. As with conclusions, there are premise indicators that serve as signposts that reasons are being offered for the main claim or conclusion. Some examples of premise indicators are:
Since . . .
For . . .
Given that . . .
Because . . .
As . . .
Owing to . . .
Seeing that . . .
May be inferred from . . .
To practice identifying premises, let us return to our seat belt example:
Don’t you know that driving without a seat belt is dangerous? Statistics show that you are 10 times more likely to be injured in an accident if you are not wearing one. Besides, in our state you can get fined $100 if you are caught not wearing one. You ought to wear one even if you are driving a short distance.
Much like a map will get you from point A to point B, putting an argument into the standard argument form will help you navigate from the conclusion to the premises and vice versa.
Notice again that this argument starts with a question: “Don’t you know that driving without a seat belt is dangerous?” The author is not really asking whether you know that driving without a seat belt is dangerous. Rather, the author seems to be asking a rhetorical question—a question that does not actually demand an answer—to assert that driving without a seat belt is dangerous. You should avoid asking rhetorical questions in the essays that you write, because the outcome can be highly uncertain. The success of a rhetorical question depends on the reader or listener first understanding the hidden meaning behind the rhetorical question and then correctly articulating the answer you have in mind. This does not always work.
For the sake of this example, however, let us do our best to try to get at the author’s intention. We could paraphrase the first premise to the following claim: Driving without a seat belt is dangerous. Does this paraphrased claim serve as a premise in support of the conclusion? In order to answer this, we need to put the conclusion in the form of a question. Again, premises are reasons offered in support of the conclusion, so if we have a well-constructed argument, then the premises should answer why the conclusion is the case. This is what we would have:
Question: Why must you wear a seat belt whenever you drive?
Answer: Because driving without a seat belt is dangerous.
This works, so the paraphrased claim that we drew from the author’s rhetorical question is indeed a reason in defense of the conclusion. So now we have one more piece of the puzzle:
Premise 1: Driving without a seat belt is dangerous.
Premise 2: ?
Premise 3: ?
Therefore, you ought to wear a seat belt whenever you drive.
Let us now move to the next sentence: “Statistics show that you are 10 times more likely to be injured in an accident if you are not wearing one.” Is this a claim that can be a support for the conclusion? In other words, if we put the conclusion in the form of a question again as we did before, would this sentence be an adequate reason in response? Let us see.
Question: Why must you wear a seat belt whenever you drive?
Answer: Because statistics show that you are 10 times more likely to be injured in an accident if you are not wearing one.
The answer provides a reason in support of the conclusion, and thus, we have another premise. Now we have most of the puzzle completed, as follows:
Premise 1: Driving without a seat belt is dangerous.
Premise 2: Statistics show that you are 10 times more likely to be injured in an accident if you are not wearing one.
Premise 3: ?
Therefore, you ought to wear a seat belt whenever you drive.
We have one more sentence left in the argument, which reads: “Besides, in our state you can get fined $100 if you are caught not wearing one.” Is this a premise? Well, it is uncertain, since the sentence is not presented in the form of a claim. So let us paraphrase it as a claim as follows: “Not wearing a seat belt can result in a $100 fine.” This is now a claim, and the paraphrasing has not altered the meaning, so we can proceed to our question: Is this a premise for the argument that we are examining? Once again, let us put the conclusion into a question:
Question: Why must you wear a seat belt whenever you drive?
Answer: Because not wearing a seat belt can result in a $100 fine.
This is a claim that can be a support for the conclusion, and thus, we have another premise. We can now see the argument presented more formally as follows:
Driving without a seat belt is dangerous.
Statistics show that you are 10 times more likely to be injured in an accident if you are not wearing one.
Not wearing a seat belt can result in a $100 fine.
Therefore, you ought to wear a seat belt whenever you drive.
The Necessity of Paraphrasing
As we have discussed, extracting the fundamental claims from a written or a spoken argument often involves paraphrasing. Paraphrasing is not merely an option but rather a necessity in order to uncover the intended argument in the best way possible. Most other arguments presented to you (especially those in the media) will not consist of only premises and the conclusion in clearly identifiable language. Furthermore, many arguments will be much longer and complicated than the seat belt argument example. Often, arguments are presented with many other sentences that do not serve the purposes of an argument, such as empty rhetorical devices, filler sentences that aim to manipulate your emotions, and so on. So your task in extracting an argument from such sources is akin to that of a surgeon—removing all those linguistic tumors that obscure the argument in order to reveal the basic claims presented and their supporting evidence. In other words, you should expect to do paraphrasing as a necessary task when you attempt to draw an argument in the standard form from almost any source.
It is important to recognize that not everyone who advances an argument does so clearly or even coherently. This is precisely why the structure of the standard argument form is such a powerful tool to command. It offers you the machinery to distinguish arguments from what are not arguments. It also helps you unearth the elements of an argument that are buried under complicated prose and rhetoric. And it helps you evaluate the worthiness of the argument presented once it has been fully clarified. You should paraphrase all claims when presenting them in the standard argument form, whether the claims are implied in a long argumentative essay or speech or in shorter arguments that may be ambiguous or unclear. (To understand the added benefits, see Everyday Logic: Modesty and Charity.)
Everyday Logic: Modesty and Charity
The goal of paraphrasing is to find the best presentation of the premises and conclusions intended. By presenting the argument offered in its best possible light, this will help you see not only how far off the argument is from an optimal defense, but also how good it is despite its bad presentation. Why should you be so charitable?
First we must keep in mind that ideas are important, even if the ideas are not ours. So we must always give our utmost due diligence to the examination of ideas. Sometimes even the roughest presentation of ideas can contain the most impressive pearls of insight. If we are not charitable to the ideas of others, then we might miss out on hidden wisdom.
Second, modesty is a good intellectual habit to develop. It is very easy to fall into the trap of thinking that our thoughts are the best ones around. This is generally far from the truth. The most fruitful innovations of mankind have been quite unexpected, often as the result of someone paying attention to others’ ideas and coming up with a new way of putting them to use. This applies to all sorts of things, including everything from the ways in which cooking methods turned into regional cuisines, to scientific discoveries, product innovations, and the emergence of the Internet.
That modesty has advantages is not a new idea. In the 1980s Peter Drucker wrote the book Innovation and Entrepreneurship, in which he recounts, among many other stories, the story of how Ray Kroc founded the burger chain McDonald’s®. As the well-known story goes, Kroc bought a hamburger stand from the McDonald brothers, along with their invention of a milkshake machine. Although Kroc never invented anything, his entrepreneurial genius was in seeing the potential of a hamburger, fries, and milkshake business that catered to mothers with little children and turning this vision into a billion-dollar standardized operation (Drucker, 1985/2007).
Even if you dislike McDonald’s, the point is that Kroc noticed the potential for something that many, including the McDonald brothers themselves, had overlooked. Gems are everywhere in the world of ideas, but we often have to dust them off, remove all the excess baggage, and extract what is good in them. Intellectual modesty allows us to do this; we don’t blind ourselves by assuming our own ideas are best. Once we seek to fully understand others’ ideas and allow them to challenge our own, we can do all sorts of good things: understand an idea more clearly, understand someone better, and understand ourselves (our values, what we find important, and so on) better as well.
Given that our human social world is characterized by diversity of ideas, modesty also marks the path of cooperation, harmony, and respect among human beings. This is one of the many small ways in which the application of logical reasoning can help us all have better lives and better relations with other people. If we could all use logical reasoning on a regular basis, perhaps we would not have as many wars and atrocities as we have today.
Thinking Analytically
Identifying an argument’s components as we have just done is an example of analytical thinking. When we analyze something, we examine its architectural structure—that is, the relation of the whole to its parts—to identify its parts and to see how the parts fit together as a whole.
Let us examine an excerpt from President Barack Obama’s (2014) speech on Ebola as a way of bringing the new skills from this section all together:
In West Africa, Ebola is now an epidemic of the likes that we have not seen before. It’s spiraling out of control. It is getting worse. It’s spreading faster and exponentially. Today, thousands of people in West Africa are infected. That number could rapidly grow to tens of thousands. And if the outbreak is not stopped now, we could be looking at hundreds of thousands of people infected, with profound political and economic and security implications for all of us. So this is an epidemic that is not just a threat to regional security—it’s a potential threat to global security if these countries break down, if their economies break down, if people panic. That has profound effects on all of us, even if we are not directly contracting the disease. (para. 8)
We have identified “The West African Ebola epidemic is a potential threat to global security” as the conclusion. What are the premises? Read the passage a few times while asking yourself, “Why should I think the epidemic is a global threat?” Obama says that the epidemic is not like others, that it is growing faster and exponentially. He moves from there being thousands of people infected, to tens of thousands, to the possibility of hundreds of thousands. So far, everything is about how fast the epidemic is growing.
In the middle of the seventh sentence, the president switches from talking about the growth of the epidemic to claiming that it has profound economic and security implications. What is the basis for the claim that the growth will have these effects? Notice that it is not in the seventh sentence, at least not explicitly. However, the last part of the eighth sentence does address this. In that sentence, Obama suggests three conditions that might lead to a global security threat: “if these countries break down, if their economies break down, if people panic.” So the extreme growth of the epidemic may lead to the breakdown of economies or countries, or it may lead to widespread panic. If any of these things happen, there are “profound effects on all of us.” Therefore, the epidemic is a potential threat to global security. We can now list the premises, and indeed the entire argument, in standard form as follows:
The West African Ebola epidemic is growing extremely fast.
If the growth isn’t stopped, the countries may break down.
If the growth isn’t stopped, the economies may break down.
If the growth isn’t stopped, people may panic.
Any of these things would have profound effects on people outside of the region.
Therefore, the West African Ebola epidemic is a potential threat to global security.
Notice that putting the argument in standard form may lose some of the fluidity of the original, but it more than makes up for it in increased clarity.
2.3 Representing Arguments Graphically
In the preceding section, we discussed the component parts of an argument and how we can identify each when we encounter them in writing. Although the standard argument form is useful and will be used throughout this book, you may find it easier to display the structure of an argument by drawing the connections between the parts of an argument. We will start by learning some simple techniques for diagramming arguments. An argument diagram (also called an argument map) is just a drawing that shows how the various pieces of an argument are related to each other.
Representing Reasons That Support a Conclusion
The simplest argument consists of two claims, one of which supports the other—which means that one is the premise and the other is the conclusion. For example:
There is snow on the ground, so it must be cold outside.
To represent this argument, we put each claim in a box and draw an arrow to show which one supports the other. We can diagram this argument in the following way:
Two boxes with an arrow between them. The top box says, “There’s snow on the ground.” The arrow points from this box to the bottom box, which reads, “It’s cold outside.”
Notice that the claims are represented by simple, complete sentences. The premise is at the start of the arrow, and the conclusion is at the end. The arrow represents the process of inferring the conclusion from the premise. Seeing snow on the ground is indeed a reason for believing that it is cold.
But arguments can be more complex. First, consider that an argument may have more than one line of support. For example:
Three boxes form an upside-down triangle. The top left box reads, “There’s snow on the ground.” The top right box reads, “It’s February in Idaho.” Both of these boxes have arrows pointing to the bottom box, which reads, “It’s cold outside.”
The important thing here is that the two lines of support are independent of each other. Knowing that it is February in Idaho is a reason for thinking that it is cold outside, even if you do not see snow. Similarly, seeing snow outside is a reason for thinking it is cold regardless of when or where you see it.
Second, it can also be the case that a single line of support contains multiple premises that work together. For example, although February in Idaho offers good grounds for thinking it is cold outside, this reason is strengthened if it also happens to be a particularly cold year. A year being particularly cold is not by itself much of a reason to think it is cold outside. Even a cold year will be warm in the summer. But a February day in a cold year is even more likely to be cold than a February day in a warm one. We represent this by starting the arrow at a group of premises (bottom):
Four boxes, one on top, one in the middle, and two on the bottom. The top box reads, “There’s snow on the ground.” This box has an arrow pointing to the middle box, which reads, “It’s cold outside.” The bottom right box reads, “It’s a very cold year,” and it is connected to the bottom left box, which reads, “It’s February in Idaho.” The bottom left box has an arrow pointing to the middle box.
Although arrows can sometimes start at a group of claims, they always end at a single claim. This is because every simple argument or inference has only one conclusion, no matter how many premises it may have.
Finally, arguments can form chains with some claims being used as a conclusion for one inference and a premise for another. For example, if your reason for thinking that there is snow on the ground is that your friend John just came in with snow on his boots, this can be indicated in a diagram as follows:
Five boxes. The top box reads, “John came in with snow on his boots.” This box has an arrow leading to a box that reads, “There’s snow on the ground.” This box has an arrow pointing to a box that reads, “It’s cold outside.” Below this box are two boxes. The box on the left reads, “It’s February in Idaho,” and the box on the right reads, “It’s a very cold year.” The bottom boxes are connected, with an arrow from the box on the left pointing to the “It’s cold outside” box.
Notice that the claim “There is snow on the ground” is a conclusion for one inference and a premise for another. From these basic patterns we can build extremely complicated arguments.
Representing Counterarguments
We will discuss one more refinement, and then we will have all of the basic tools we need for constructing argument maps. Sometimes lines of reasoning count against a conclusion rather than support it. If we look out the window and notice that most of the students outside are not wearing coats, that might lead us to believe that it is not very cold even though it is February and we see snow. We will represent this sort of contrary argument by using a red arrow with a slash through it:
Six boxes. The top box reads, “John came in with snow on his boots.” This box has an arrow pointing to a box that reads, “There’s snow on the ground,” which has an arrow pointing to a box that reads, “It’s cold outside.” Next to the “snow on the ground” box is a box that reads, “Most people aren’t wearing coats.” This box is connected by a red arrow to the “It’s cold outside” box. Below the “cold outside box” are two boxes. These boxes are connected to each other, and the right box reads, “It’s a very cold year.” The box on the left reads, “It’s February in Idaho,” and it has an arrow pointing to the “cold outside” box.
Just as with supporting lines of reasoning, opposing lines may have multiple premises or chains. From the point of view of logic, these lines of opposing reasoning are not really part of the argument. However, such reasoning is often included when presenting an argument, so it is useful to have a way to represent it. This is especially true when you are trying to understand an argument in order to write an essay about it. It is good practice to note what objections an author has already considered so that you do not just repeat them.
With that, you have all the basic tools you need to create argument diagrams. In principle, arguments of any complexity can be represented with diagrams of this sort. In practice, as arguments get more complex, there are many interpretational choices about how to represent them.
Diagramming Efficiently
One issue that arises when creating argument diagrams is that including each premise and conclusion can make diagrams large and cumbersome. A common practice is to number each statement in an argument and make the diagram with circled numbers representing each premise and conclusion. See Figure 2.1 for an illustration of the seat belt example from the previous section.
Figure 2.1: Diagramming the structure of an argument
This diagram shows the relationship between each of the sentences in the seat belt example. Here are the claims: 1. Don’t you know that driving without a seat belt is dangerous? 2. Statistics show that you are 10 times more likely to be injured in an accident if you are not wearing one. 3. Besides, in our state you can get fined $100 if you are caught not wearing one. 4. You ought to wear one even if you are driving a short distance. Notice how numbering the individual components of each argument and diagramming them will help you see the relationship among the pieces and how the pieces work together to support the conclusion.
A diagram that shows a circled 2 with an arrow pointing to a circled 1. The circled 1 has an arrow pointing downward to the conclusion, 4. A circled 3 is on the right and also points to the conclusion.
The seat belt example is not a complex argument, but the diagram in Figure 2.1 is able to show how the hidden assertion in the first question is supported by the second statement and how, together with the third assertion, the conclusion is supported. Sketching diagrams that show the relationship among the premises and their connections to the conclusion is very helpful in understanding complex arguments. Yet you must keep in mind that the diagramming is the second stage of the process, since you will have to first identify the elements of the argument.
2.4 Classifying Arguments
There are many ways of classifying arguments. In logic, the broadest division is between deductive and inductive arguments. Recall that Section 2.1 introduced the notion of inference, the process of drawing a judgment from the reasons offered in the premises. The distinction between deductive and inductive arguments is based on the strength of that inference. A conclusion can follow from the premises very tightly or very loosely, and there is a wide range in between. For deductive arguments, the expectation is that the conclusion will follow from the premises necessarily. For inductive arguments, the expectation is that the conclusion will follow from the premises probably but not necessarily. We shall explore these two kinds of arguments in greater depth in subsequent chapters. In this section our goal is to achieve a basic grasp of their respective definitions and understand how the two types differ from one another. Finally, we will improve our understanding of the concept of an argument by comparing arguments to explanations, which are often mistaken for arguments.
Deductive Arguments
A cartoon that shows a woman asking a man a question. He asks, “Can I get input from the guys at the bar on this one?” He then asks, “Multiple choice guys. Wainscoting is: A. a style of body painting at Mardi Gras, B. the second baseman for the 1953 Red Sox, C. a type of paneling.” The guys at the bar shout all As and Bs for answers. The man asking the question then says, “The consensus is C.” The woman who originally asked the question says, “I’ll give you that one for using sound deductive reasoning.”
In logic the terms deductive and inductive are used in a technical sense that is somewhat different than the way the terms may be used in other contexts. For example, Sherlock Holmes, the protagonist in Sir Arthur Conan Doyle’s detective novels, often referred to his own style of reasoning as deductive. In fact, the popularity of Sherlock Holmes introduced deductive reasoning into ordinary speech and made it a commonplace term. Unfortunately, deductive reasoning is often misunderstood, and in the case of Sherlock Holmes, his clever style of reasoning is actually more inductive than deductive. For example, in The Adventure of the Cardboard Box, he says:
Let me run over the principal steps. We approached the case, you remember, with an absolutely blank mind, which is always an advantage. We had formed no theories. We were simply there to observe and to draw inferences from our observations. (Doyle, 1892/2008, para. 114)
The foregoing does not describe deductive reasoning as it is employed in logic. In fact, Sherlock Holmes mostly uses inductive rather than deductive reasoning. For now, the simplest way to present deductive arguments is to say that deductive reasoning is the sort of reasoning that we normally encounter in mathematical proofs. In a mathematical proof, as long as you do not make a mistake, you can count on the conclusion being true. If the conclusion is not true, you have either made an error in the proof or assumed something that was false. The same is true of deductive reasoning, because good deductive arguments are characterized by their truth-preserving nature—if the premises are true, then the conclusion is guaranteed to be true also. Consider the following deductive argument:
All married men are husbands.
Jacob is a married man.
Therefore, Jacob is a husband.
In this example, the conclusion necessarily follows from the given premises. In other words, if it is true that all married men are husbands and, moreover, that Jacob is a married man, then it must be necessarily true that Jacob is a husband.
But suppose that Jacob is a 3-year-old boy, so he is not a married man. Would the argument still be a good deductive argument and, thereby, truth preserving? The answer is yes, because deductive reasoning reflects the relations between premises and the conclusion such that if it were to be the case that the premises were true, then it would be impossible for the conclusion to be false. If it so happens that Jacob is a 3-year-old boy, then the second premise would not be true, and thus, the necessity for the conclusion to be true is broken.
However, this does not mean that all we need are true premises and a true conclusion. Good deductive arguments are not free form; rather, they use specific patterns that must be followed strictly in the inferential operation. Although this might sound rigid, the greatest advantage of good deductive arguments is that their precise structure guides us into grasping a truth that we might not otherwise have recognized with the same certainty. The use of deductive reasoning is quite broad—in science, mathematics, and the examination of moral problems, to name a few examples. Subsequent chapters will demonstrate more about the powerful machinery of deductive arguments.
Inductive Arguments
In contrast to deductive arguments, good inductive arguments do not need to be truth preserving. Even those that have true premises do not guarantee the truth of their conclusion. At best, true premises in inductive arguments make the conclusion highly probable. The premises of good inductive arguments offer good grounds for accepting the conclusion, but they do not guarantee its truth. Consider the following example:
The produce at my corner store is stocked by local farmers every day.
They have a bakery, too, and they refill their shelves with fresh-baked bread twice a day.
I have been shopping at my corner store continuously for 5 years, and every day is the same.
Therefore, my corner store will have fresh produce and baked goods every day of the week.
Let us suppose that all the premises are true. After 5 years of going to the corner store and getting to know its practices and the quality of its daily offerings, the conclusion would seem to be highly probable. But is it necessarily true? At some point the store may change hands, close, or experience something else that interrupts its normal operations. Such cases show that even though the reasoning is good, the conclusion is not guaranteed to be true just because the premises are true.
Another way to think of what is going on here is to address a likely familiar fact of the human condition: Past experience does not guarantee that the future will be the same. Think of that great car you loved that did not require any expensive maintenance—and then suddenly one day it started to break down bit by bit with age. Time changes the performance of things. Or think of the great quality of a clothing brand you counted on year after year that one day was no longer as good. Products also change with time as the leaders of the manufacturing company change or the standards become somewhat relaxed. Things change. Sometimes the changes are for the better, sometimes for the worse. But our observation of how things are now and have been in the past does not guarantee that things will remain the same in the future. Accordingly, even if the conclusion in our corner store example seems sufficiently justified for us to venture saying that it is true, the fact is that at some point it could change. At best, we can say that the premises give us good grounds to assert that it is probably true that the store will have good produce and baked goods this coming week.
Despite having a weaker connection between premises and conclusion, inductive arguments are more widely used than deductive arguments. In fact, you have likely been using inductive reasoning your entire life without knowing it. Think about the expectation you have that your car, house, or other object will be in the location you last left it. This expectation is based on good inductive reasoning. You have good reasons for expecting your car to be sitting in the parking space where you left it. We can represent your reasoning as follows:
I left my car in that spot.
I have always found my car in the same parking spot I left it in.
Therefore, my car will be in that spot when I return.
Of course, having good reason is not the same as having a guarantee, as anyone who has experienced having their vehicle stolen can attest. This is the difference between deductive and inductive arguments. Because inductive arguments only establish that their conclusions are probable, the conclusions can turn out to be false even when the premises are all true. The chance may be small, but there is always a chance. By contrast, a good deductive argument is airtight; it is absolutely impossible for the conclusion to be false when the premises are true. Of course, if one of the premises is false, then neither kind of argument can establish its conclusion. If you misremember which spot you parked in, then you are not likely to find your car immediately, even if it is right where you left it.
Arguments Versus Explanations
Mastering logical reasoning requires not only understanding what arguments are, but also being able to distinguish arguments from their closest conceptual neighbors. Although it might be clear by now why news articles, debates, and commands are not considered arguments, we should take a closer look at explanations, because they are commonly mistaken for arguments and present a similar framework. Arguments provide a methodical defense of a position, presenting evidence by means of premises in support of a conclusion that is disputed. Explanations, in contrast, tell why or how something is the case.
Suppose that we have the following claim:
We have to travel by train instead of by plane.
If you disagree with this decision, then you might question this claim, thus presenting a request for evidence. Accordingly, an argument would be the appropriate response. We could then have the following:
The total cost for plane tickets is $2,000.
The total cost for train tickets is $1,000.
We have a budget of $1,200 for this trip.
Therefore, we have to travel by train instead of by plane.
Now, suppose that you do not question the claim, but you still want to know why we have to travel by train. This is not a request for evidence for the conclusion. Rather, this is a request for the cause that leads to the conclusion. This is thus a request for an explanation, which may be as simple as this:
Because we do not have enough money for plane tickets.
The point of an argument is to establish its main claim as true. The point of an explanation is to say how or why its main claim is true. In arguments, the premises will likely be less controversial than the conclusion. It is difficult to convince someone that your conclusion is true if they are even less likely to agree with your premises. In explanations, the thing being explained is likely to be less controversial than the explanation given. There is little reason to explain why or how something is true if the listener does not already accept that it is true. Unlike arguments, then, explanations do not involve contested conclusions but, instead, accepted ones. Their point is to say why or how the primary claim is true, not to provide reasons for believing that it is true. This explanation might be fairly straightforward, but distinguishing between arguments and explanations in real life may seem a bit more blurry.
As an example, suppose you try to start your car one morning and it will not start. You recall that your son drove the car last night and know that he has a bad habit of leaving the lights on. You see the light switch is on. You now understand why the car will not start. In our scenario, you found out your car would not start and then looked around for the reason. After noticing that the light switch was on, you came up with the following explanation:
Your son left the lights on.
Leaving the lights on will drain the battery.
A drained battery will prevent the car from starting.
That’s why your car won’t start.
It is an explanation because you already know that your car will not start; you just want to know why.
On the other hand, suppose that after your son got home last night, you noticed that he left the lights on. Rather than turn them off or tell him to do it, you decide to teach him a lesson by letting the battery go dead. In the morning you have the following conversation with your son:
You: I hope you don’t need to go anywhere with the car this morning.
Son: Why?
You: You left the car’s lights on last night.
Son: So?
You: The lights will have completely drained the battery. The car won’t start with a dead battery, so it’s not going to start this morning.
In this case the thing you are most sure of is that your son left the lights on. You reason from that to the conclusion that the car will not start. In this scenario, knowing that the lights were left on is a reason for believing that the car will not start. You are trying to convince your son that the car will not start, and the fact that he left the lights on last night is the starting point for doing so. We can show the structure of your argument as follows:
Your son left the lights on.
Leaving the lights one will drain the battery.
A drained battery will prevent the car from starting.
Therefore, your car won’t start.
Notice that the structure of this argument is the same as the structure of the explanation example. The only difference is whether you are trying to show that the car will not start or to understand why it will not start after already realizing that it will not. Finding the structure will help you understand the details of the argument or explanation, but it will not, by itself, help you determine which one you are dealing with. For that, you have to determine what the author is trying to accomplish and what the author sees as common ground with the reader. Understanding the structure of what is said can help you become clearer about what the author is doing, so it is a good thing to look for, but understanding the structure is not enough.
Determining whether a passage is an argument or an explanation is thus often a matter of interpreting the intention of the speaker or writer of the claim. A good first step is to identify the main point or central focus of the passage. What you are looking for is the sentence that will be either the conclusion to the argument or the claim being explained. If the author has not done so, paraphrase the main claim as a single, simple sentence. Try to avoid including words like because or therefore in your paraphrase. Ask yourself, if this is an argument, what is its conclusion? Once you have identified the potential conclusion, try to determine whether the author is attempting to convince you that that sentence is true, or whether the author assumes you agree with the sentence and is trying to help you understand why or how the sentence is true. If the author is trying to convince you, then the author is advancing an argument. If the author is trying to help you get a deeper understanding, the author is providing an explanation.
It is important to be able to tell the difference between arguments and explanations both when listening to others and when crafting our own arguments and explanations. This is because arguments and explanations are trying to accomplish different goals; what makes an effective argument may not make an effective explanation.
Moral of the Story: Arguments Versus Explanations
If the main claim is accepted as true from the beginning, then the speaker or writer may be advancing an explanation, not an argument. If the point of a passage is to convince the reader that the main claim is true, then it is most likely an argument. Of course, you may question an explanation, thus requesting an argument that the explanation is correct.
