Reflections on Reasoning

Raymond S. Nickerson

• Publisher: Routledge
• Year: 2019
• ISBN:
  9781317739210
• Edition: 1
• Topic: Psicología
• Subtopic: Psicología experimental

This book is an adaptation of a report entitled Notes about Reasoning, prepared under a project on The Training of Higher Cognitive Learning and Thinking Skills that was sponsored by the National Institute of Education. My purpose in producing the notes was to help me clarify my own thinking about reasoning and how the ability to reason effectively might be enhanced in the classroom. I did not intend to write a textbook on reasoning or a scholarly review of research on reasoning processes, and this book is not presented as either now. It still has the character of a collection of thoughts; it is being published with the hope that some of the ideas and suggestions in it may stimulate some others, especially teachers and students, to reflect more than they otherwise might have upon what it means to reason effectively. One does not, of course, become an effective reasoner by reading a book on reasoning or by taking a course in reasoning. Learning to reason well is surely a lifelong process—or at least a lifelong challenge. If this book is useful in helping some readers to see the value of an enduring commitment to that challenge, it will have served its purpose. I wish to thank the NIE Project Officers, Patricia Butler and Joseph Psotka, for their support and encouragement. I am grateful also to John Swets, Richard Herrnstein, David Perkins and Carol Chomsky for helpful comments on an early draft of the manuscript, to Anne Kerwin and Patricia Carroll for typing the manuscript and to Brenda Starr and Frank DiPace for making electronic delivery of it to the printer possible by working around the differences between the sending and receiving systems. Special thanks to my wife, Doris, for her constant help of countless types, and most especially for bringing into the world the four beautiful people to whom this book is dedicated.

1 Introduction

This book is about reasoning. It is not a textbook in the conventional sense. Nor does it provide a prescription for how to reason effectively. It is a collection of thoughts regarding various aspects of reasoning and what it means to reason well.

The intent is to raise questions about reasoning; to invite the reader to reflect on the nature of reasoning; and to suggest that reasoning has many facets, none of which can safely be ignored by anyone who would reason effectively. Underlying the book is the assumption that while skill at reasoning is not likely to be acquired quickly and effortlessly, one can improve one’s reasoning ability if one is sufficiently motivated to do so. Nothing is assumed with respect to the reader except interest in the subject of reasoning and a tolerance for ideas that are still in the process of being formed.

Reasoning is viewed here as a matter of both attitude and knowledge: one is unlikely to reason well about any subject unless one is deeply desirous of doing so, and one has some knowledge of the subject about which the reasoning is to be done. Neither a closed mind nor an empty one is likely to produce much that would qualify as effective reasoning. On the other hand, an open and reflective mind, coupled with a little knowledge and an eagerness to acquire more, will reason as a matter of course.

1.1 What Is Reasoning?

Reasoning, as the term is used here, encompasses many of the processes we use to form and evaluate beliefs—beliefs about the world, about people, about the truth or falsity of claims we encounter or make. It involves the production and evaluation of arguments, the making of inferences and the drawing of conclusions, the generation and testing of hypotheses. It requires both deduction and induction, both analysis and synthesis, and both criticality and creativity.

Reasoning also has to do with the careful and critical use of language. Indeed, reasoning and language usage are so tightly intertwined that it is often difficult to tell whether a particular problem should be considered a problem of reasoning or one of language usage—and perhaps, at least for practical purposes, it does not matter which way it is perceived.

There is no easy prescription that will guarantee effective reasoning. To be sure, there are rules of logic, a knowledge of which should decrease the probability of certain types of identifiable reasoning errors; but there is much to reasoning that cannot be codified as a set of rules. Judgment plays an indispensable role, as do attitudes. We must make judgments of the relevance of arguments to issues, for example, as well as judgments of the plausibility of assertions and of the credibility of information sources. With respect to attitudes, effective reasoning requires an openness to evidence—a willingness to examine it objectively and to be influenced by it—and a commitment to truth, even in light of an awareness that the truth may sometimes be difficult or impossible to ascertain.

Reasoning is, in short, not easily defined in a satisfactory way. We can talk about it and consider various aspects of what the word seems to connote in common usage; but we are likely to find it difficult to come up with a crisp definition that will do justice to the richness of the concept and, at the same time, be precise enough to serve as a criterion for determining in all cases that X is an instance of reasoning, while Y is not.

In this book, the discussion of reasoning is structured around three key concepts, belief, assertion, and argument. Belief is understood to be an intuitively meaningful notion: it is confidence that a particular thing is true, as evidenced by a willingness to act as though it were. The concept of an assertion does double duty: on the one hand, it can be an expression of a belief; on the other, it can be a component of an argument. An argument is a set of assertions that is used to support a belief.

Deciding the order in which to discuss these topics poses a problem because no matter what order we choose, there will be times when some aspect of one of the topics would be easier to understand if the other topics have already been discussed. Moreover, no order is clearly more defensible than all the others, so our choice must be arbitrary to some degree. We might start with arguments, on the grounds that that is really what reasoning is all about; or with assertions, because they are the stuff of which arguments are made, as well as the vehicles for expressing beliefs; or with beliefs, because everyone understands intuitively what they are.

Here, the topics are considered in the following order: first, beliefs; second, assertions; third, arguments. Although the topics are discussed individually, it should be borne in mind that they are of special interest because of the ways in which they relate to each other. Assertions are of interest because they are both the components of arguments and the means by which we can represent beliefs. Arguments are of interest because they are used to form, sustain, or modify beliefs. We might say that beliefs are of interest in their own right, inasmuch as our beliefs, to a large extent, define what we are and determine what we do. However, we focus here on such issues as the defensibility of beliefs and the plausibility of the arguments used to support them.

1.2 Organization Of The Book

Beyond this introductory chapter, the book is organized as follows: Chapter 2 discusses, in a discursive way, the relationship between reasoning and the closely associated concepts of language, logic, inventiveness, knowledge, and truth. It ends with a contrast between reasoning and rationalizing and a consideration of three types of factors that can impede reasoning. Chapters 3,4, and 5 discuss beliefs, assertions, and arguments, respectively. Chapter 6 considers various stratagems that people use to persuade or to win disputes, and Chapter 7 describes several ways in which our reasoning is known often to go astray. Chapter 8 presents a few suggestions for attempting to improve our own reasoning capability.

Think about it

Consider the following questions:

• What does the term reasoning mean to you?
• What are some of the aspects of effective reasoning?
• What are some major impediments to effective reasoning?
• How might we characterize the differences between good and poor reasoners?
• Why is reasoning important in everyday life?

2 Reasoning in Perspective

2.1 Reasoning And Language

The relationship between reasoning and language is a complicated one. Sometimes it is not clear how to distinguish between reasoning deficiencies and problems arising from careless or inept use of language. If in reading a sentence we understand what the sentence says explicitly, but fail to understand what it implies, is that a failure of language comprehension or of reasoning? If I claim to believe both of two contradictory statements, is it more reasonable to assume that I must misunderstand at least one of the statements or that I am being illogical?

A particularly bothersome aspect of language that has implications for reasoning is the problem of ambiguity and the inherent lack of definitional precision in the way we use words. The problem shows up in more than one guise. It occurs, for example, when two parties to a discussion use the same word but attach different meanings to it. It also happens when the same word is used in two premises in an argument, but with different meanings in the two cases. A humorous but convincing example of the latter is the familiar demonstration that a ham sandwich is better than eternal happiness:

Nothing is better than eternal happiness.

A ham sandwich is better than nothing.

Therefore, a ham sandwich is better than eternal happiness.

The problem here, of course, is in the ambiguity of the premises. Rewording the argument so that the fallacy becomes clear may not be as easy as you think. Superficially the argument appears to be perfectly sound. It is identical in form, is it not, to the following argument, which we accept without difficulty:

Tom is taller than Carl.

Pete is taller than Tom.

Therefore, Pete is taller than Carl.

The problem with the first argument is that its premises are ambiguous because the term nothing is used to mean different things in different contexts. In particular, there are two ways to interpret the first premise:

• 1a. Having nothing at all is better than having eternal happiness.
• 1b. There is nothing that is better than eternal happiness; or, equivalently, the set of things that are better than eternal happiness has no members.
• There are also two ways to interpret the second premise:
• 2a. Having a ham sandwich is better than having nothing at all.
• 2b. A ham sandwich is not better than anything.

If the two premises were interpreted as 1a and 2a, then the argument would be sound, which is to say, the conclusion would indeed follow. However, it seems unlikely that anyone would interpret the first sentence as 1a. Most people reading the argument would probably interpret the two premises as 1b and 2a, respectively. Given those interpretations, the argument does not have a logical structure, because the premises do not have a common term.

Here is another example that illustrates how the imprecise use of language can be confusing. All of us are familiar with many sayings, which are sometimes called maxims, proverbs, adages, or aphorisms. Have you ever noticed that it is often easy to find pairs of sayings that seem to have opposite meanings? The fact that we can find such pairs is a little strange because these sayings usually are thought of as summarizing widely acknowledged truths.

Consider the following:

A stitch in time saves nine.

Haste makes waste.

Many hands make light work.

Too many cooks spoil the broth.

You cannot teach an old dog new tricks.

One is never too old to learn.

The point is that what appear to be contradictory statements when they are juxtaposed can also appear to express self-evident truths when they are seen in isolation or in certain specific contexts. Each of the sayings just noted, while apparently contradicting the one with which it is paired, can certainly be viewed as true in some sense. That is, each applies sometimes and in certain circumstances, but not at other times or in other situations. The problem is that when such sayings are used to make points, the conditions under which they are assumed to apply are usually not specified.

While we cannot hope to do more here than simply recognize the complex relationship between language usage and reasoning, it is certainly fair to say that careful language usage should greatly facilitate reasoning, and that, conversely, it probably is not possible to reason effectively unless we use language carefully.

The importance of language and of the need for care in using it will be illustrated several times in this book. Special attention will be given to the subject, however, in the discussion of assertions in Chapter 4.

Think about it

• Find as many examples as you can of contradictory sayings. Then try to rephrase or qualify them so that they preserve the original meaning but are no longer contradictory.
• List a few words, particularly nouns and verbs, that could have different meanings in different contexts for different people, and consequently could contribute to misunderstanding or the appearance of faulty reasoning, if not used carefully.

2.2 Reasoning And Logic

The question of whether reasoning follows the rules of logic is an old one and has been debated many times. Do the rules of logic reflect the way people naturally think? Do they represent only how skilled thinkers think? Or are they prescriptions for how we should think? That issue will not be discussed at length here.

Unquestionably, an explicit understanding of some of the basic principles of logic is very useful; anyone who has such an understanding is likely to be able to reason more effectively than someone who does not. It is useful, for example, to understand the modus ponens and modus tollens forms of the conditional, or hypothetical, syllogism. (They are discussed in Chapter 5.) However, it is not necessary that we be familiar with the terminology of formal logic—that is, with such terms as modus ponens and modus tollens—in order to be able to reason effectively. It is essential, though, that we understand at least some of the basic principles of inference, such as those illustrated by the ponens and tollens modes of argument.

Moreover, familiarity with some of the terms of logic can undoubtedly be helpful in reasoning, and a knowledge of rules of formal logic is a great asset indeed.

It is important to recognize that logic represents only one aspect of reasoning, and that a complete understanding of the rules of formal logic in and of itself will not assure effective reasoning. Logic deals with the validity, or form, of deductive arguments. It provides methods and rules for restating given information so as to make what is implicit explicit. It has little to do with the determination of truth or falsity. It does not provide techniques for going beyond the information given, except that it makes explicit what has been given only by implication.

Effective reasoning requires the ability to think up arguments as well as to assess their validity. It requires the ability to generate hypotheses as well as to test them, to determine the degree of relevance certain information has to an issue, and to give appropriate weight to that information in attempting to decide the issue. It also requires the ability to judge the plausibility of assertions, the ability to bring evidence to bear on one’s system of beliefs, and the willingness to modify those beliefs in accordance with that evidence as appropriate.

In short, reasoning ability involves the ability to detect logical fallacies in formal arguments, but much more than that, it requires a lot of what we might consider aspects of inventiveness. Any view of reasoning that overlooks the less formal and more creative aspects of the process is an overly narrow view and is an inadequate foundation for programs to enhance reasoning. The following section expands on the point.

Think about it

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Table of contents

• Cover
• Half Title
• Title Page
• Copyright Page
• Dedication Page
• Table of Contents
• Preface
• Foreword by P. N. Johnson-Laird
• 1. Introduction
• 2. Reasoning in Perspective
• 3. Beliefs
• 4. Assertions
• 5. Arguments
• 6. Stratagems
• 7. Some Common Reasoning Fallacies
• 8. Conclusion
• Appendix A: Answer Key