Critical Thinking
The Power of Effective
Decision Making
David A. Hunter Ph.D.
© David Hunter 2005
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Contents
Chapter 1: Critical Thinking, An Intellectual Virtue ________________________ 3
THE NATURE OF CRITICAL THINKING ____________________________________ 3
WHY REASONS MATTER __________________________________________________ 5
STAGE FOUR CRITICAL THINKING ________________________________________ 6
PERSONAL AUTONOMY ___________________________________________________ 8
THE MTV METHOD _______________________________________________________ 9
OPEN-ENDED PROBLEMS ________________________________________________ 11
THE AUTONOMY EXERCISE ______________________________________________ 13
Chapter 2: Critical Thinking: A Leadership Virtue _________________________ 15
CRITICAL THINKING AND LEARNING ORGANIZATIONS __________________ 15
GOOD DECISION MAKING _______________________________________________ 17
PRACTICAL OPEN-ENDED PROBLEMS ____________________________________ 19
BUILDING LEARNING ORGANIZATIONS __________________________________ 21
ARE YOU A STAGE 4 LEADER? ___________________________________________ 21
THE JUSTIFICATION EXERCISE __________________________________________ 22
Chapter 3: The Structure of Reasons _____________________________________ 25
REASONING AND ARGUMENTS ___________________________________________ 25
RECOGNIZING ARGUMENTS _____________________________________________ 25
IDENTIFY THE PROPOSITIONS ASSERTED ________________________________ 27
DEPENDENT AND INDEPENDENT REASONS _______________________________ 30
SUB-ARGUMENTS________________________________________________________ 32
LOGICAL STRENGTH ____________________________________________________ 33
IMPLICIT PREMISES _____________________________________________________ 35
QUIZ ____________________________________________________________________ 36
Chapter 4: Assessing the Evidence_______________________________________ 39
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CLAIMS ABOUT MEANING _______________________________________________ 39
Definitions _____________________________________________________________________ 39
Frameworks ____________________________________________________________________ 41
CLAIMS ABOUT MATTERS OF FACT ______________________________________ 43
Specific Claims _________________________________________________________________ 43
General Claims _________________________________________________________________ 46
Chapter 5: Drawing Conclusions from the Evidence _______________________ 57
REASONING ABOUT ALTERNATIVES _____________________________________ 57
CONDITIONAL REASONING ______________________________________________ 59
REASONING WITH ANALOGIES __________________________________________ 62
Chapter 6: Reasoning about Values _____________________________________ 67
THE MEANING OF “OUGHT” STATEMENTS _______________________________ 67
WHAT MAKES AN OBLIGATION BINDING? ________________________________ 68
RESOLVING CONFLICTING OBLIGATIONS ________________________________ 69
Chapter 7: Assessing and Constructing Arguments ________________________ 71
CLARIFY MEANING ______________________________________________________ 71
ASSESS FOR TRUTH______________________________________________________ 72
EXPLORE THE VALUE ___________________________________________________ 73
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Chapter 1: Critical Thinking, An Intellectual Virtue
THE NATURE OF CRITICAL THINKING
Robert Ennis, one of the leading researchers in the field of critical thinking, offered the following, now classic definition of critical thinking.
Critical Thinking is reasonable and reflective thinking focused on deciding what to believe or do.
Deciding what to believe is a matter of deciding what the facts are, figuring out
what the world is like, or at least what one little corner of it is like. Deciding
what to do is a matter of deciding first what to value or to strive for, or how to
weigh competing values, and then, second, how best to achieve it.
To make either kind of decision we first need a method, some conception of how
we can go about deciding what the facts are or what we should value. Decision
makers thus face two kinds of questions.
Question of Belief: How should I decide what to believe?
Question of Value: How should I decide what to value?
Often, perhaps typically, decision makers face a complex mix of both questions.
For we cannot know how to get what we most value without knowing something about the resources we have and the obstacles we face. Likewise, we cannot decide what we ought to value without knowing something about what we
can in fact achieve. In such cases, decision making requires aligning our beliefs
about how the world is with our values about how it should be.
Bad decisions often result from a failure to line up our beliefs and our values in
this way. We fail to achieve reasonable goals because we did not know enough
about our actual resources or about the obstacles in our way. Even worse, we
strive hard to reach unrealistic goals, ones that we would never have chosen had
we known more about the facts at hand. Critical thinking can help prevent these
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kinds of errors by providing a method for approaching, analyzing and resolving
cases of misaligned beliefs and values.
When Ennis said that critical thinking is reasonable part of what he had in mind
is that it is guided by rules. Some of the rules concern the conditions under
which beliefs are justified or not justified, and what kinds of evidence are appropriate for beliefs of different kinds. Other rules concern what conclusions we can
reasonably draw from the evidence we have. Together, these rules form a systematic method for making or evaluating a decision about what to believe or do.
Critical thinking is reflective because using this system of rules requires constant
monitoring and careful judgment. In this way, critical thinking is like a craft or
practice in that doing it well requires thinking about what one is doing while one
is doing it. Perhaps virtuoso critical thinkers can think critically automatically, in
the way a virtuoso jazz musician plays without thinking about it. But for the rest
of us, thinking critically requires regular practice and constant self-assessment.
Of course, we are all critical thinkers to some degree. Indeed, critical thinking
can be taught only to someone who already can think critically to some extent.
John Dewey famously put the point this way: “A being who could not think
without training could never be trained to think; one may have to learn to think
well, but not to think.”1
Creative thinking
A lot of attention has been paid in recent years to creative thinking and to its important role in effective decision making. There is no doubt that creativity is essential to making good decisions. Thinking of alternative conclusions, finding
objections, examples and counter-examples, and reframing problems are all creative acts we will discuss in what follows. Developing the skills to think creatively is essential to becoming a good thinker.
But it is just as essential that one be able to think critically about these alternatives, examples and counter-examples. There is a difference between a helpful
and effective reframing of an issue and one that makes the problem harder to
solve. Evaluating alternatives, considering whether a given claim is supported
by the evidence, determining and comparing the credibility of different sources
of information and constructing well-reasoned arguments are all critical, as opposed to creative, acts, requiring the skills and knowledge discussed in this book.
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WHY REASONS MATTER
Critical thinking is reasonable in a second and more fundamental sense. Being a
critical thinker requires having reasons for our decisions, whether about what to
believe or what to do. It is not enough simply to believe that the world is some
way: we need to have good evidence, or better yet some proof, that it is that way.
And it is not enough simply to desire some goal: we need to show that it is a reasonable and worthwhile goal, one we can actually achieve and one who’s
achievement will have been worth the effort. In the absence of adequate evidence or justification, being a critical thinker requires that we remain undecided
about what to believe or to do.
Reasons are needed because decision making is aimed at getting things right.
We want our beliefs to be true and our actions to be effective. By basing our beliefs only on adequate evidence we increase the chance of getting things right.
Regrettably, of course, this is not a guarantee against error, but beliefs based on
inadequate evidence or on no evidence at all will be true only by luck and actions
based on unreasonable expectations or inadequate planning succeed only by
chance. It is surely poor policy to rely on luck and chance when deciding what
to believe or do.
I will say more later about what precisely this demand for reasons amounts to
and what counts as adequate reasons in different kinds of cases, but we can note
now that reasons for a decision are adequate only if they are in a certain sense
impersonal or universal. Whether a decision is based on adequate reasons has
nothing to do with who is making the decision. Something counts as a reason for
me to believe or do something only if it counts equally as a reason for everybody
else. The demands of rationality are the same for all of us.
It is sometimes said that everyone is free to have their own beliefs. This is uncontroversial if it means that no one should be forced to believe something, or
that it is sometimes OK for people to disagree about the facts. But this attitude of
tolerance does not mean that we are free to believe what we want regardless of
the evidence. In the absence of adequate evidence the proper response is to
withhold belief, not to cling stubbornly to a point of view. When people we recognize to be experts disagree about some issue, reason demands that we should
remain agnostic. And when others disagree with us and we cannot produce adequate evidence to support our views we should step back and admit that we
might not be right. Far from indicating intellectual cowardice, agnosticism in the
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face of inadequate evidence reveals a mind that is open to the demands of reason.
Reasons are obviously needed to justify a decision about what to do to achieve
some goal or end, but one also needs to have reasons for choosing that goal itself.
Having a conception of the good life, or at least of what it would be for one’s
own life to be good, is itself a good thing, since it can help us decide what to do
and what to pursue. Having such a conception provides structure to our lives, a
framework within which we can define and evaluate our life. But if there are no
constraints on what conception we can choose, if it does not matter what conception of a good life we pick, then the life we lead, even if it is in perfect coherence
with that conception, is ultimately arbitrary.
Perhaps at some point, this demand for reasons must end. Perhaps we must ultimately admit that “Look, this is what I value, and I cannot justify or rationalize
it. But I do value it, even if others do not.” There are deep philosophical and
moral issues involved here, and it may well be that ultimately our goals have
whatever value they do simply in virtue of the fact that we chose them. Still,
there is an important difference between actively choosing and committing to
goals one cannot rationalize or justify and merely finding oneself with them.
Leading an examined life requires honesty and clarity about the source of one’s
values, even if that source is ultimately one’s own choice.
STAGE FOUR CRITICAL THINKING
Being a critical thinker requires having mastered certain skills and methods
needed for thinking through various kinds of problems and we will consider
some of these methods in Chapters 3, 4 and 5. But being a critical thinker requires more than just having these skills, since anyone can fail to employ the
skills one has. A critical thinker must also want to use the critical thinking skills
she has.
In the last few decades, a consensus has emerged among researchers that there
are identifiable stages in becoming a critical thinker, and that the stages are only
indirectly related to one’s skills. The stages have been described and distinguished in different ways and more research is needed to determine the precise
developmental path. But the research suggests something like the following series of stages.
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Stage 1. Belief Seeker: sees the need for decision-making.
A Belief Seeker takes the goal of decision making to be simply acquiring
belief. She uncritically takes tradition, personal experience and the word
of perceived authorities as sources of truth, seeing no special need to question whether these sources are reliable, or to compare them when they
yield conflicting evidence. When questioned about her beliefs, she describes their origin, how she came to have them, instead of offering reasons for retaining them.
Stage 2. Confirmation Seeker: sees the need for evidence-based decision making.
A Confirmation Seeker takes the goal of decision making to be finding a
confirmed belief. Unlike the Belief Seeker, she appreciates the need to
have evidence or reasons for her belief. But she sees this as a need to find
evidence to support the beliefs she already has. She ends her inquiry
when she finds evidence to support her beliefs. Consequently, she treats
evidence that confirms her beliefs as more reliable than evidence that undermines them and favors available evidence over efforts to collect more
evidence.
Stage 3. Evidence Seeker: sees the possibility of conflicting evidence.
An Evidence Seeker sees the goal of decision making to be finding a balance of evidence. Unlike the Confirmation Seeker, she understands that
evidence must come before belief, and so actively seeks out alternative
points of view and different sources of evidence. While she recognizes
different sources of evidence, she cannot see how to compare them or how
conflicts in evidence from different sources can be rationally resolved.
Consequently, she resists reaching a final decision, treating every belief as
equally justified.
Stage 4. Justification Seeker: sees the need to evaluate evidence.
The Justification Seeker sees the goal of decision making to be a belief
based on the best of the available evidence. Like the Evidence Seeker, she
actively seeks out alternative points of view and different sources of evidence, and prefers to withhold belief than to have an unjustified belief.
But she understands the conditions under which different sources are reliable, knows what kinds of support are needed for claims of different
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kinds, and is able to rationally adjudicate conflicts in evidence from different sources.
Research suggests that people proceed through these stages roughly in order,
though many never fully reach stage 4. The transition from one stage to another
may take longer for some than for others, and reaching the higher stages seems
to correlate with post-graduate education or extensive professional experience.
A person’s stage may depend on the subject matter, so that a stage 4 thinker
about medical issues may be a stage three thinker about moral issues. There is
no evidence of regression in stages, though this is not inconceivable. As research
continues a clearer picture of the developmental stages will emerge.
Even though more research is needed, the model of the four stages is helpful in
understanding what it is to be a critical thinker. For I think we can all recognize
ourselves or people we know in the stages. I have known students who clearly
fell in one or another stage, and I have watched some transition from one to another. I have even noticed myself acting as if I were in stage three, refusing to
consider how to sort out conflicting evidence. And sometimes, pressed by my
children or students about some decision or belief, I reveal myself as a stage 2
thinker, content with the available evidence when it is clear that further inquiry
might well reveal conflicting evidence. It can take a real effort to admit that my
decision was hastily made, that I failed to walk the walk. Perhaps the natural, inevitable attitude is to overestimate one’s critical thinking prowess. The exercise
at the end of Chapter 2 may help identify room for real improvement in one’s
own critical thinking capacity.
PERSONAL AUTONOMY
Socrates, the grandfather of modern philosophy, is reported to have claimed that
the unexamined life is not worth living. In part he meant that it is all too easy to
adopt the beliefs and values of our times and let them determine the structure
and path of our life. Such a life would be bad, Socrates thought, not because the
beliefs and values would necessarily be mistaken or ones we would not have
chosen on our own. Relying on authority and tradition has its place, and no advanced science is possible without an accumulation of inherited truths. But an
unexamined life is bad, Socrates thought, because unless we decide for ourselves
what to believe and what to value we are really leading someone else’s life, not
our own.
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The idea of leading a life of one’s own is the idea of Autonomy, which literally
means “self-governance”. To be autonomous is to give laws to oneself, to determine for oneself the structure and course of one’s life. Should I go to law school
or graduate school in philosophy? How do I find a balance between success in
my career and the fulfillments that comes from family? Being a critical thinker
does not guarantee a life of autonomy, since as Socrates would have been the
first to admit, it is an act of great bravery to live a life of one’s own. But it is hard
to see how one could be autonomous, how one could decide for oneself what
makes a life worth living, without being a critical thinker.
Rene Descartes, the father of modern philosophy, decided to take up Socrates’
challenge for autonomy. In a striking series of meditations, Descartes described
how he tried to uncover and evaluate the beliefs and values he had inherited
from his family, teachers and society. He decided to retain only those beliefs and
values for which he could provide adequate reasons. Not every philosopher
agrees with the conclusions he reached, or with the standards he set for what
should count as “adequate reasons”, but his deep commitment to autonomy and
to the practice of critical thinking left a lasting impression on modern thought.
The self-examination exercise described below is modeled on Descartes’ own experience.
THE MTV METHOD
Being a critical thinker involves knowing how to make decisions for oneself
about what to believe and what to value. In later chapters we will consider some
of the logical tools and techniques that can make this easier to do. But the tools
and techniques are useful only if we already have a clearly framed question or
problem. In fact, often the most difficult and usually the most important task is
to get clear on just what the decision is about. The MTV method can help with
this initial task.
Decisions about what to believe share an abstract form with decisions about
what to value, and the MTV method applies in similar ways to both. In Chapter
6, I will discuss in more detail how to apply this method in connection with decisions about value. For now I will focus on decisions about what to believe.
The method rests on the fact that we must ask three kinds of questions about a
given belief or claim: What does it mean? Is it true? Why does it matter?
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Meaning
Before deciding whether to accept some claim, statement or belief, we need to be
as clear as we can about what it means. This is a matter of getting clear on how
would things have to be for that claim to be true. Several question are central in
trying to clarify meaning:






How should I formulate the claim in my own words?
What kind of claim is it:
o a definitional claim about meaning
o an empirical claim about how the world is
o a generalization about some phenomena
o a claim about the logical relations between facts
o a normative claim about the nature or worth of some value
or ideal
What are the key terms involved, and how should I define them?
Can I provide a real life example, or a fictional illustration of the
claim.
How can I distinguish this claim from similar, related ones?
What else would be true if this claim were true?
Truth
Before deciding whether to accept some claim we need to consider the reasons to
think it is true. But we also need to consider reasons to think the claim is not
true. What kinds of reasons are relevant to the truth of a claim depends on what
kind of claim it is.
Deciding whether a definition is true requires comparing a proposed definition
to dictionary entries and to the opinions of others. Unfortunately, there is no
foolproof way to determine whether a proposed definition is true. And because
linguistic usage continuously changes, there is little point in hoping for a lasting
definition. For most practical purposes, it is enough to achieve an explicit
agreement among those involved in the decision.
Deciding whether an empirical claim is true requires relying on sources of information or evidence. There are many different sources, including
perceptual experience
testimony or the word of an outside authority
measurement
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memory
controlled experiment
Certain sources are appropriate for some kinds of claims, but not for others.





Memory is appropriate for deciding whether I left my keys at home, but
(at least in my case) not for deciding whether George Bush won Kansas.
An authority, like the New York Times, may be appropriate if the question is how many Democrats voted for the war in Iraq, but not for
whether it is raining outside my office right now.
Observation might reveal whether it is sunny now, but not whether it
will be sunny tomorrow.
An experiment is needed to decide whether vitamin C can prevent the
common cold, but not to decide whether men over 65 are a higher risk
of colon cancer.
A measurement that will reveal whether a newly implemented protocol
has improved productivity might not show us whether it has also increased morale.
In each case, knowing just how things would be if the claim were true can help
us to decide how to go about figuring out whether the claim is true.
Value
Before deciding whether to believe some claim we need to know what hangs in
the balance, what depends on it. Here are some of the questions that are relevant
to determining the value of the issue.
Why is it important to decide whether to believe this?
What is the history of attempts to answer this question?
What would deciding this question require me to do?
Do I have the resources needed to find the answer?
How might knowing the answer help me achieve my goals?
OPEN-ENDED PROBLEMS
In some cases, a decision can be made without addressing all three questions. If
the problem and our reasons for wanting to know the answer are clear, then we
can focus our efforts on the question of Truth. How many of our customers are
in the Midwest? In how many states did George Bush win a majority in 2000?
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What effect would closing this DMV Office have on county receipts? What does
the IRS consider “income”? Can I afford this tuition without a student loan? In
such cases, there is no serious obscurity in the question or in why knowing the
answer might matter to us.
But some problems are open-ended. A problem is open-ended when it is not
clear from the outset what would count as a solution to it. In such cases, progress may require addressing all three levels of analysis at once. Part of what
makes open-ended problems so difficult to solve is that it is easy for a disagreement about truth to camouflage disagreements about meaning and value. In
such a case, it will be very hard to make progress until the hidden disagreements
are identified, distinguished and sorted out. The MTV method can help.
Hidden disagreements like this are common in philosophy, where the focus is
almost always as much on meaning and value as on truth. Debates over, say,
free will turn as much on distinguishing different senses of “free will” and on
why it might matter to us whether we have free will as on whether we are in fact
free in any given sense. Does being free require having alternatives, or does it
only require that we be able to do what we want? Is freedom important for personal integrity and moral responsibility, or can we conceive of a morally valuable
life that is nonetheless determined by forces outside our control? If freedom is
just a matter of doing what one wants, even when one’s wants are determined by
outside forces, is this a kind of freedom worth fighting for? Answering these
kinds of questions requires deciding which meaning of the word “freedom” captures the kind of freedom we want to have.
In theory, progress in addressing this problem is best made by first carefully distinguishing different senses of “free will”, different conceptions of what being
free would be like. Once these different conceptions are clear, we can ask which
of them best captures why being free matters to us. Invariably, no single conception captures everything about why being free has seemed worth fighting for,
some capture certain elements of what makes freedom and autonomy worthwhile but not others. But once we have identified different kinds of freedom,
and decided which ones we want, we can then ask whether we in fact have freedom in any of those senses.
In practice, however, it is nearly impossible to separate these questions so neatly.
It is not uncommon for philosophers who seem to disagree about whether we
have free will to in fact be disagreeing about what they mean by “freedom”. In
such a case, they are effectively talking past each other.
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THE AUTONOMY EXERCISE
When Rene Descartes took up Socrates’ challenge to lead an examined life and
asked himself, “Why do I have the beliefs and values that I do?”, we can distinguish the question of how he came to have that belief or value from the question
of why he should retain it. The first is a question about the origins of one’s beliefs and values, about the history of one’s system of belief. By itself, this tells us
nothing about whether we should retain that system. The second question is
about whether one should retain that belief or value, and so is about deciding for
oneself what to believe and what to see a worthwhile, about personal autonomy.
The Autonomy Exercise is designed to give you a sense of the nature and value
of the kind of radical self-examination Descartes undertook.
1. List 4 or 5 core values that you believe a good person exemplifies.
(Some examples: honesty, charity, patience, generosity, etc.)
2. Meaning: try to define one of them. Some of them may be much easier to
define than others. Since one point of this exercise is to practice defining,
pick one whose meaning you are unclear about, or which is controversial.
You should do each of the following:
a. Self-reflection: try to formulate what you mean by it.
b. Other opinions: ask three or four friends what they mean by it.
c. Authority: consult three dictionary definitions.
d. Note the differences and try to formulate a final definition. Even
small differences in wording can be significant.
3. Truth: be willing, for 1 or 2 days, to let the value guide your life. Here are
some things to consider.
a. How well did you succeed? Describe a situation where you failed.
b. Did you notice others failing to live up to it? Describe.
c. How did you feel when you were successful/when you failed.
d. Did you find you had to reflect even more on the meaning of the
value, and perhaps even alter your understanding of it? For instance, did you find yourself unsure, on some occasion, what (say)
genuine honesty in fact involved. Describe this reflection.
4. Value. Describe, if you know, how you came to have this value and explain why you will retain it (or abandon it). Some things to consider:
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a. Did it come from your family, church, friends, media,…? How do
these forces work?
b. Do your friends value it as much as you do (did)? Is it important to
you that they do? Why?
c. What reasons could you offer to someone who doubted its value?
Whether this exercise succeeds depends wholly on the amount of sincere effort
you put into it: the harder you try, the more you will learn about yourself and
about what it is like to be autonomous.
Recommended Readings:
Socrates’ views were reported by his student Plato. Descartes’ works can be
found in the following:
Descartes, Rene. Discourse on Method and Meditations on First Philosophy, 4th Ed.
Hackett, 1999.
Plato. The Works of Plato. McGraw-Hill Humanities/Social Sciences/Languages;
1965
The following are now classic academic studies on the definition, assessment or
development of critical thinking.
Fisher, Alec and Scriven, Michael. Critical Thinking: its Definition and Assessment.
University of East Anglia, Center for Research in Critical Thinking, 1997.
King, Patricia and Kitchener, Karen. Developing Reflective Judgment: Understanding
and Promoting Intellectual Growth and Critical Thinking in Adolescents
and Adults. Jossey-Bass Wiley, 1994.
Norris, Stephen and Robert Ennis. Evaluating Critical Thinking, Pacific Grove, CA,
Midwest Publications, 1989.
There are lots of good books available on creative thinking, including:
De Bono, Edward. De Bono’s Thinking Course. Revised Edition. Facts on File Publishers. 1994.
Foster, Jack. How to Get Ideas. Berrett-Koehler Publishers; 1st ed edition, 1996.
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Chapter 2: Critical Thinking: A Leadership Virtue
In Chapter 1, I described how being a critical thinker is essential to personal autonomy, and I identified a stage 4 thinker as a kind of ideal critical thinker,
someone who not only understands the rational demand for evidence-based decisions, but is able to compare, contrast and evaluate evidence from multiple
sources before making a decision. In this chapter I want to argue that critical
thinking, and stage 4 thinking in particular, is just as essential to effective leadership and overall organizational health.
CRITICAL THINKING AND LEARNING ORGANIZATIONS
In the last two decades, the relationships between critical thinking and organizational success have been brought to the fore by two trends. One is the growing
recognition, highlighted by David Garvin, Peter Senge and others, that organizational health requires organizational learning, capitalizing on the valuable
knowledge implicit in an organization’s workforce. The other is the trend,
spearheaded by Tom Peters and others, away from centralized decision making
and towards empowering small teams of employees to make decisions on the
front lines. Organizations whose employees have strong critical thinking skills
and attitudes will be better positioned to benefit from these two trends.
First, Peter Senge, David Garvin and others have focused attention on the importance of organizational learning and, more specifically, on the ideal of a
learning organization. Garvin defines a learning organization as follows.
A learning organization is an organization skilled at creating, acquiring, interpreting, transferring and retaining knowledge, and at
purposefully modifying its behavior to reflect new knowledge and
insights.
As he points out, the basic idea is that the overall health of an organization
should be measured, not solely in bottom line terms, but in terms of the organization’s ability to change and adjust as market and competitive forces change.
This flexibility requires a continuous sensitivity to those forces, an awareness of
what they are and a readiness to take advantage as they change. Only an organization dedicated to constant learning at all levels can maintain that flexibility.
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It is not just leaders who need to be thinking critically about the organization‘s
nature and position. This kind of constant learning and reflection has to be occurring at all levels, nurtured and rewarded from the leaders, so that insights
from the front line as well as from the head office are acquired, analyzed and
then transferred throughout the organization. Critical thinking about current
practices, business assumptions, and the frameworks used to define and assess
business strategy need to be going on at all levels. Critical thinking is in this way
central to the ideal of developing a learning organization.
Garvin laments the fact that so few American organizations, including business
schools and universities themselves, who often pride themselves on the importance they place on critical thinking and on leading an examined life, have as
yet fully dedicated themselves to becoming learning organizations. I suspect
that one of the reasons is that we tend to treat decision making as if it were something very different from learning. Indeed, Garvin comments that managers often say to him that they are too busy making decisions to spend time learning.
But decision making, or at least good decision making, is inseparable from learning.
My point is not just that good decisions are based on good evidence, and that
gathering this evidence requires learning. This is true, but it does not go far
enough. Deciding on what else to believe or on the best course of action is itself a
matter of learning from the evidence. Decision making, whether its is deciding
what to believe or deciding what to do, is aimed at getting it right. We want our
beliefs to be true and our plans to be effective. Reframing decision-making as
itself a form of learning brings into focus the fact that managers, those who describe themselves as decision makers, could more accurately describe themselves
as learners. They are already in a learning organization, even if they do not quite
realize it.
A second recent trend in management studies also points to the value of critical
thinking for organizational health. Tom Peters and others have argued that organizational success requires small, autonomous teams, with decision making
authority. Not only does this streamline the decision making process, enabling
faster and better decisions, but it increases employee empowerment, engagement, and commitment. Of course, implementing and empowering such teams
is not easy.
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No doubt some managers delay forming these kind of teams out of fear they will
lose control of the decision making process, though this is hardly a legitimate excuse. But surely many also fear that devolving decision making powers will increase the risk of bad decisions. One way to address this legitimate worry is to
empower the teams with first rate decision making skills, pairing a new authority to make key decisions on their own with a responsibility to employ a first rate
decision making process. After all, whether a decision is a good one has more to
do with the decision making process used than with layers of managerial oversight. Critical thinking training, assessment and development can play a central
role in enabling successful autonomous teams.
Organizations committed to empowering their employees with greater learning
and decision making responsibilities can benefit from investing in the critical
thinking skills and attitudes of their employees. Not only will this make it easier
for managers to trust what their employees say and decide, but it will make it
easier for the employees to take their new responsibility seriously. An organization of learners and decision-makers can thrive only to the extent that it knows
how to learn and make good decisions.
GOOD DECISION MAKING
I have been discussing empowering employees to make good decisions. But just
what makes a decision good, what criteria should we use when assessing decisions? One thing we know is that an effective leader guides organizations to decisions that are stable and legitimate. Using the tools and techniques of critical
thinking can help yield decisions that are stable and legitimate. But what is
more, it can also ensure decisions that are manifestly stable and legitimate, and
this “manifest rationality” is distinctive of effective leadership.
A stable decision is one that can withstand changes in business conditions and
information. A decision that is based on good reasons and that is arrived at reflectively is more likely to be stable than one arrived at instinctively in the dark.
Whether the decision is about current business conditions or about long-term organizational goals, stability is crucial to success. Sometimes, of course, an organization must change direction and abandon a decision. But even then, the new
course ought to be a stable one, since no successful organization can shift in the
wind. Especially in times of decision crisis, critical thinking is crucial.
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A legitimate decision is one that enjoys widespread buy-in. At a minimum, this
requires that everyone involved believe and value the same things, that all sides
agree on the current business conditions or on the organization’s strategic vision.
But an agreement is superficial unless there is also agreement on the underlying
reasons, on why it is that one should believe that those are the current business
conditions or on why that vision of the future is worth pursuing. Superficial
agreement that masks underlying disagreement about the nature or worth of the
chosen goals can lead to infighting and, ultimately, disunity. The basic point is
the simple one that reasons motivate better than orders.
One way to guarantee that a decision is legitimate is to let everyone involved
participate in making it. But this is hardly feasible as a decision making strategy
for most organizations. In large organizations, effective decisions are manifestly
rational. A leader should make clear that their decisions are reasonable and reflective, that they are based on good reasons and arrived at through reliable
methods. The best way to do this is to make the reasons themselves clear.
From my own experience serving on various college wide committees and from
observing various college administrators, I have learned that it is not enough for
a decision to have been well made: it must be seen to have been well made. In
part this is a matter of the decision maker’s reputation. A leader with a reputation for reasonable and reflective decision making stands a better chance of finding followers. But invariably questions get raised about the underlying rationale
for the decision, and even about whether relevant alternatives were considered,
and the best decision will seem illegitimate without a clearly laid-out explanation
of why it ought to be accepted.
I have characterized a good decision as one that is manifestly stable and legitimate. But what about being right? Wouldn’t a decision to believe something
that turned out to be false be a bad decision, and if one’s plans failed to achieve
their goals wouldn’t that show that it was a mistake to adopt those plans in the
first place? The short answer has to be No, and I think we can all recognize why.
Even the best made decisions, like the best laid plans, are subject to forces outside our control. Whether a decision was well made has to do with the process
used in making it, and not with whether it proved to be the right decision.
Of course, decisions do aim at getting it right, and so we want our decision making process to “track the facts”, to be reliable most of the time. When we learn
that we made a mistake, the proper response is to inquire into how to prevent
that kind of mistake in the future, by ensuring that the process will be sensitive
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to that mistake’s source. This feedback loop is itself a manifestation of critical
thinking. Good decisions, in the sense of decisions that are right, are more likely
to derive from good decision making procedures.
There is, though, an important connection between the legitimacy of a decision
and its “rightness”. A legitimate decision is one that enjoys widespread buy-in.
That means more than just to most accept it. It means that, given the reasons put
forward in support of it, most see it as a good or even the best decision. Of
course, the fact that most people believe something does not mean that it is the
right answer, but legitimacy can be a helpful check on rightness. If most of the
team agree that the decision is a good one, then that is good reason to think the
decision is on the right track, even if in the end it proves to have been mistaken.
PRACTICAL OPEN-ENDED PROBLEMS
In Chapter 1, I described the MTV method in relation to an open-ended problem
in philosophy. But open-ended problems are by no means restricted to philosophy. They occur anytime a problem involves questions about meaning, truth
and value all at once. Charting a strategic direction and establishing assessment
metrics and targets are open-ended problems. But so is trying to deal with a specific customer’s complaint. What makes a problem open-ended is not its bottomline significance but the way it brings together questions about meaning, truth
and value.
Suppose an organization has low employee morale and wants a plan to improve
it. Solving the problem requires answering some question about meaning. What
precisely is meant by “morale”? Is it limited to simple job-satisfaction, or to a
broader attitude to one’s life? Is it even possible to separate these kinds of attitudes? What is the specific morale issue within the organization? Are the workers feeling bored and unchallenged, or do they feel over-burdened and that they
lack the resources they need? These are questions about meaning, about how we
should define the problem, about what the problem really is. Little progress can
be made until such questions are addressed.
Questions of value are close by. Why is low morale seen as a problem? Does it
matter because low morale may reduce productivity. Is the concern that continued low morale would lead to demands for greater compensation? Or is there
regional competition for workers, and the fear is that low morale may impel
workers to take jobs with the competition? Until answers to these questions
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about what makes some situation a problem, no substantial progress can be
made in solving the problem.
Finally, there are many questions about truth. What evidence is there to think
morale is low? How have we been measuring morale, and is that the most reliable method? How can we track changes in morale over time, especially given
changing employees and business conditions and given that workplace morale is
influenced by broader life-issues? How does our employee morale compare to
employee morale of our competitors? Only once we decide on what we mean by
morale, and why improving it matters to us, can we decide what techniques are
best at addressing its value to us?
This brief discussion makes clear that questions about how to improve morale
cannot be answered separately from questions about what morale is and why it
might matter to organizational success. Answering questions about value may
forces changes in how the problem is framed, in perceptions about the problem
itself. And discoveries about how morale is best measured may well determine
how best to think about the nature and value of the phenomena itself.
Deciding on a plan to improve morale faces several risks. Most obviously, the
decision may not be effective. A desire to quickly find a solution to the problem,
to address the questions about truth, may prevent a serious attempt to answer
the questions about meaning and value. In this case, a plan to improve morale
may quickly run into fatal obstacles that a more thorough investigation into the
nature and value of the problem would have predicted.
An even more serious risk is that hidden disagreements will prevent successful
implementation. If there is hidden disagreement about what the problem is or
about why it matters to the organization, this will make it difficult to agree to a
plan to improve morale. But even if a plan is agreed to, unless the hidden disagreements are recognized, there will be further disagreements when it comes to
implement the plan. Managers with different conceptions of the problem will
implement a solution in different, possibly even conflicting ways. Managers
who disagree about the need for raising morale will disagree about what counts
as success.
Only a comprehensive agreement, one that includes agreement at all three levels,
can ensure a stable and legitimate decision. The point of distinguishing these
three levels is not to suggest that it is trivial to distinguish these kinds of disagreements. It often is not, and to make matters worse it is sometimes impossible
20
to answer one kind of question without answering another. My claim is simply
that knowing that there are these kinds of disagreements, and knowing how to
identify and resolve them, is essential to effective decision making.
BUILDING LEARNING ORGANIZATIONS
I argued above that critical thinking is crucial to organizational learning and employee empowerment. But what can leaders do to further organizational learning? Ideally, everyone in the organization should be a stage 4 thinker. But we all
know too well that not everybody is. What can be done to promote stage 4
thinking? Several lessons are clear.
Lesson 1. Leaders must themselves be stage 4 thinkers. They ought to be able to
consider different points of view, seek out and evaluate different sources of evidence, and base their decisions on the best evidence. Not only will this help ensure they make stable, legitimate decisions, but by actively and explicitly modeling the kind of thinking they want from others they will manifest their commitment to it.
Lesson 2. Leaders must be sensitive to differences in thinking styles and stages.
Hidden disagreements about what it takes to reach a decision, about the need to
seek out alternatives and to evaluate sources of evidence, are obstacles to stable
and legitimate decision making. A leader must be able to identify and correct for
differences in thinking styles that prevent the emergence of legitimate and stable
agreements without alienating others.
Lesson 3. Leaders must create an environment in which employees can improve
their thinking styles. Measures to assess the thinking styles of group members
should be administered, and appropriate training and development should be
encouraged. There is no reason to believe stage 4 thinking is out of reach for anyone, but there is good reason to think it can be achieved only through careful and
specific training.
ARE YOU A STAGE 4 LEADER?
Being a stage four thinker is a kind of intellectual virtue, and like any virtue we
all have it to some degree, we can all get better at with practice, and we are all
reluctant to admit when we fall short. Just as we all want to count as honest,
even though we know we sometimes tell lies, we all want to count as critical
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thinkers, even though we know we sometimes make hasty, uninformed or otherwise poor decisions. A relatively straightforward exercise can help us assess
for ourselves to what extent we model stage 4 thinking, that is, the extent to
which we are stage 4 leaders. The exercise relies on a distinction between lying
and BS-ing.
We can all agree that it is often wrong to lie. Saying what you believe to be false
in order to mislead someone robs him of the opportunity to make up his own
mind on the facts, and everyone has a right to this kind of opportunity. And, by
all accounts, known liars make lousy leaders.
But what if someone makes a claim without having done enough to make sure
that the claim is true, or even without being completely clear about what the
claim requires for truth? What if the claim merely repeats something they have
always believed, or taken for granted? What if they are simply BS-ing? It
wouldn’t be right to call this lying, since the intent is not to mislead. But there is
nonetheless something wrong about making a claim without quite knowing
what the claim amounts to, or without being able to back it up.
Indeed, one might think that BS-ing is in one respect worse than lying. For a liar
at least has the appropriate concern for the value of truth. Indeed, it is because
she sees the value of truth that she refuses to share it. She is greedy about truth
precisely because she takes it to be so valuable. But someone who is merely BSing, making claims without a proper concern for their meaning or truth, cares
less for knowledge and truth than does the liar. A BS-artist is interested in impressing others, or with just talking, than in being right or in communicating the
truth. Which would you rather have for a boss or an employee, a liar or a BSartist? If you were a boss, which would you promote over the other?
Being a BS artist is incompatible with being a stage 4 thinker. For stage 4 thinkers recognize the need to base their decisions, and so their claims, on an adequate
consideration of the evidence, and realize that this requires some understanding
of how to evaluate different kinds of evidence and claims. So, to find out just
how much of a stage 4 leader you are, we can ask: to what extent do I engage in
or tolerate BS?
THE JUSTIFICATION EXERCISE
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Like the Autonomy Exercise, the Justification Exercise involves self-assessment.
But the goal of this exercise is simpler. For two or three days, as you go about
your normal activities, be willing to be a stage 4 thinker and leader.
When you make or hear a decision, about what to believe or what to do, at work
or at home, to employees, employers, friends or family, reflect a moment, and
ask yourself the following questions.
1. MEANING:
a. Did I claim precisely what I meant to claim?
b. Could I have been more precise/accurate?
c. How much time did I spend deciding how best to formulate my
claim?
d. Could I explain how evidence in support of this kind of claim is
best collected, or how to evaluate the reliability of an evidence
source?
2. TRUTH:
a. How much time did I spend thinking about the evidence I have for
this claim?
b. How much time did I spend thinking about the reliability of the
source I relied on?
c. Did I say what evidence I relied on?
d. How much time did I spend considering alternative answers/decisions?
Describe three or four occasions in which you succeeded or failed.
How did the occasion make you feel?
Did you notice how others’ reacted?
Did you notice occasions when others succeeded or failed?
Did you point this out to them? How did they react?
How did others react?
Recommended Readings
The following are excellent, recent works on decision making in business:
Hoch, Stephen J., Kunreuther, Howard C., Gunther, Robert E. Wharton on Making
Decisions. New York, John Wiley and Sons, Inc., 2001.
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Peters, Tom and Waterman, Robert J. In Search of Excellence. New York, Harper &
Row, 1982.
Russo, J. Edward and Schoemaker, Paul J.H., (with Margo Hittleman) Winning
Decisions, New York, Doubleday, 2002.
The following are excellent works on organizational learning.
Argyris, Chris. On Organizational Learning. Malden, MA. Blackwell Publishers,
1999.
Garvin, David. Learning in Action. Boston, Harvard Business School Press, 2000.
Senge, Peter. The Fifth Discipline. New York. Doubleday, 1990.
The contrast between a liar and a BS-artist is developed in:
Frankfurt, Harry. On Bullshit, Princeton, Princeton University Press, 2005.
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Chapter 3: The Structure of Reasons
We have discussed the nature of critical thinker and we have identified Stage 4
Thinking as a kind of ideal of critical thinking. Because being a critical thinker is
a kind of intellectual virtue it requires careful, reflective practice. But it also requires some basic knowledge, tools and techniques. This Chapter discusses the
structure of reasons: how evidence can be organized and marshaled to support
beliefs. Chapter 4 discusses different kinds of evidence and when to trust them.
Chapter 5 discusses some simple methods for deciding what conclusions to draw
from that evidence. Together, these tools and techniques will help you become a
Stage 4 thinker.
REASONING AND ARGUMENTS
Critical thinking is primarily concerned with reasoning, which is the process of
providing evidence for the truth of a belief or the value of some goal or desire. In
both kinds of cases, we support the claim by relating it logically to other claims.
In this chapter, we will study the nature of this kind of logical relation.
We will focus our discussion on reasoning that is aimed at deciding what to believe as opposed to what to value. The abstract structure is the same in both cases. In the final chapter, we will look more closely at reasoning aimed at deciding
what to value.
Reasoning that is aimed at deciding what to believe or do is traditionally called
an argument. In ordinary English, an argument is an emotionally heated discussion or debate between opponents. But for our purposes, an argument is simply
any attempt, whether in writing or in conversation, to provide reasons to accept
some decision.
RECOGNIZING ARGUMENTS
The first step in assessing an argument is making sure that the author or speaker
really is intending to give an argument. We use language to do lots of different
kinds of things, and a piece of text can serve different purposes:
Narrative: describe a series of events.
Opinion: state one’s opinion.
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Explanation: citing an event’s cause.
Argument: giving reasons to believe some proposition.
Looking at the letters to the editor page in a local news paper is educational because one can see the variety of motives behind letters to the editor. It often
happens that the letter writer’s intent is simply to offer their opinion on some issue, to have their voice heard, or to point out and correct a mistake in a news article. Often, of course, the author’s goal is precisely to give some reason or reasons for her point of view on some issue.
There is, unfortunately, no sure fire way to tell when someone is trying to offer
reasons for their view. Often, though, an author will make clear that she is giving reasons by using special words to indicate what the argument’s premises are
and what its conclusion is.
Premise Indicators
Since
Because
As
For
Given that
Assuming that
Inasmuch as
The reason is that
In view of the fact that
Given that
Conclusion Indicators
Therefore
Thus
So
Consequently
As a result
It follows that
Hence
Which means that
Which implies that
It follows that
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If a piece of text or a speech contains these words, then this is good reason to
think an argument is present. These words also help us to identify the argument’s conclusion and to distinguish them from her reasons.
In the end, though, the only sure-fire way to tell whether a text contains an argument is to ask:
Is the author trying to convince me to believe something?
If YES, then it is (probably) an argument.
IDENTIFY THE PROPOSITIONS ASSERTED
Once you have determined that the author or speaker is indeed trying to convince you to believe something or to make some decision by giving you reasons,
the next step is to identify all the different claims being made in the argument.
Once again, looking at a letter to the editor is helpful here, for it is surprising
how poorly letter writers are at making their claims clear.
To identify the claims being made is to identify all of the propositions that are
asserted. A proposition is a claim that is true or false.
George Bush is a Republican.
Dick Cheney is a Democrat.
You could think of a proposition as a bit of factual information, information that
is either accurate (as in the first example) or inaccurate (as in the second). To assert a proposition is to claim that it is true. To do this, we usually need a complete declarative sentence.
Unfortunately, identifying the propositions asserted in an argument is not as
simple as identifying all of the grammatically complete sentences in the argument. There are several reasons for this.
1. Different sentences can assert the same proposition.
Bill is a liar.
Bill is mendacious.
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Jane did better on the test than Peter.
Peter did worse than Jane on the test
Because different sentences can assert the same proposition, some arguments
contain fewer propositions than sentences. Indeed, eliminating repetitiveness is a
regular problem in analyzing arguments.
2. A sentence can assert more than one proposition.
Consider this sentence
Bill’s wife is mad at him.
This sentence really contains all the following bits of information (and then
some):
Bill has a wife
His wife is mad
His wife is mad at him
So that sentence really expresses three propositions.
Another kind of sentence that asserts more than one claim is a conjunction, a sentence containing the word “and”.
George Bush is President and Dick Cheney is VP.
Hillary Clinton is a Senator and a Democrat.
These sentences assert two propositions.
A conjunction is a sentence of the form “P and Q”.
“P” and “Q” are the conjuncts. Both conjuncts are
asserted.
3. A complex sentence does not always assert every proposition it expresses.
Consider these complex sentences:
If it will rain, then I will bring my umbrella.
It will rain or I will bring my umbrella.
In those complex sentences, we find two propositions:
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It will rain
I will bring my umbrella
And those complex sentences could be true even if one of these propositions was
false. If you were to use one of those complex sentences to make a claim, one
would not be claiming that it is raining or that you will bring an umbrella. Rather, you would be claiming that some logical relation holds between these
propositions. (We will study just what those claims are in later chapters.) So,
those propositions are not asserted, they are just expressed, by those complex sentences.
To tell whether a complex sentence asserts a proposition it expresses, use the following test:
Ask: could the sentence as a whole be true even if the expressed
proposition were false?
If Yes: then the proposition is merely expressed, not asserted.
If No: then the proposition is both expressed and asserted.
A conditional is a sentence of the form “If p, then
q”. “p” is the antecedent; “q” is the consequent.
Neither “p” nor “q” is asserted.
A disjunction is a sentence of the form “p or q”. “p”
and “q” are the conjuncts. Neither conjunct is asserted.
Some other special cases are worth paying attention to. Compare the following
sentences:
Americans who love sports drink a lot of beer.
Americans, who love sports, drink a lot of beer.
The second, but not the first, asserts that Americans love sports.
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The clause "who love sports" is a restrictive clause in the first sentence, because it
serves to restrict the subject to Americans who love sports. In the second sentence it is an un-restrictive clause, because it does not restrict the subject but says
something about that subject.
Finally, compare the following:
Bush is President.
Jane said that Bush is President.
Ethan wondered whether Bush is President.
All three sentences involve the proposition that Bush is President. But only the
first one asserts it. The other two do not assert that he in fact is President, because
they could be true even if someone else were President. Just because Jane says
something, or Ethan wondered it, does not make it true. In the second and third
sentences, "Bush is President" occurs as a non-asserted noun clause.
Whether a noun clause is asserted depends on the verb that comes before the
“that”. For in the following cases, the proposition that Bush is President occurs
as an asserted noun clause.
Miranda knows that Bush is President.
Emily proved that Bush is President.
The reason is that in these cases, if the complex sentence is true, then Bush is
President. If Miranda knows something, then she is right, and if Emily proved it,
then it is true. So, in using these sentences to make a claim about Miranda or
Emily one would also be claiming that Bush is President.
For each of these propositions, compose three sentences that express it but do not
assert it.
I like ice cream
Jane is President
DEPENDENT AND INDEPENDENT REASONS
Once we have identified the argument’s premises and conclusion, we can identify its logical structure, that is, how its premises are supposed to relate to its con-
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clusion. More specifically, we need to decide whether the premises are working
together to support the conclusion, that is, whether the premises are dependent,
or whether they provide independent support for the conclusion.
To see the difference, consider the following arguments.
James has a terrible memory, and to succeed at medical school you
have to have a good memory, so James should not go to medical
school.
James does not like being around sick people, and he faints at the
sight of blood, so James should not go to medical school.
These arguments have the same conclusion, that James should not go to medical
school, and they differ in their premises. But there is a further difference, a difference in their logical structure.
In the first argument, the premises work together to support the conclusion. Neither one, all on its own, provides as much support for the conclusion as the two
of them do together. If it is true that James has a terrible memory and also true
that doctors need good memories, then all of this, when put together, is good
reason to think James should not go to medical school. But neither one, on its
own, is good reason to think that Jones should not go to medical school. In fact,
the second premise does not even say anything about James at all! The premises
depend on each other in the argument.
In the second argument, the premises really have nothing to do with each other.
Each one provides some reason to think the conclusion is true, and neither one
really depends on the other to provide this logical support. These premises provide independent support for the conclusion.
Unfortunately, there is no foolproof way to tell whether premises are independent or dependent, but there are some helpful tips:
Words Test
Ideally, there should not be words in the conclusion that do not occur in a premise. So: if the conclusion has a word that occurs only in one premise, and one
that occurs only in another, then the premises are probably dependent.
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James has a terrible memory, and to succeed at medical school you
have to have a good memory, so James should not go to medical
school.
To get all the key words found in the conclusion, we need both premises.
False Premise Test
Ideally, if two premises support a conclusion independently, then each one
would support the conclusion even if the other one was false.
So: suppose, for the sake of the argument, that one of the premises was false.
Ask: would the other premise still support the conclusion?
If yes, then the premises are probably independent.
If no, then they are probably dependent
If we supposed that James in fact had an excellent memory, then
the fact that success at medical school required such a memory
could not by itself provide good reason to think James should not
attend medical school. Alternately, if we supposed that James had a
terrible memory, but that success at medical school did not require
a good one, then we would again have no reason to accept the conclusion that James ought not to go to medical school.
PRACTICE EXERCISE
Using the following propositions as conclusion,
Torturing babies for fun is morally wrong.
compose two arguments:
One with two dependent premises
One with two independent premises.
SUB-ARGUMENTS
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Sometimes, an argument contains a sub-argument: an argument for one of the
premises.
(i) Because people have a right to life, (ii) they have a right to defend their life. (iii) Gun control violates a person’s right to defend
their life. So (iv) gun control is wrong.
In this argument, the very first premise, that people have a right to life, is in fact
a premise for the second claim, that people have a right to defend their life. This
second premise, then, together with the third one, supports the conclusion that
gun control is wrong.
PRACTICE EXERCISE
What are the premises and conclusion in the following arguments. Are there any
sub-arguments?(Answers are at the end of the chapter.)
Neither parole nor probation is justifiable. They are a demonstrable failure in
preventing criminals from committing further crimes. They undermine the deterrent impact of the laws on criminals, while demoralizing crime victims with
their outrageous leniency. Most important, they jeopardize public safety.
The Soul is immortal. It does not die, but lives forever. It existed before birth, and
will continue to exist after death. It is completely indestructible. There is nothing
that can make it go out of existence. The soul exists forever, and cannot be destroyed. It is therefore separate from the body. The soul is one thing, the body
another. The body dies: the soul lives forever. They are utterly distinct.
LOGICAL STRENGTH
Once we have identified an argument’s logical structure, we can evaluate its logical strength. Since the aim of an argument is to show that a certain proposition
is true, an argument should ideally prove that its conclusion is true.
To prove that some conclusion is true, the premises must be true, since you cannot prove anything without getting the facts right to begin with. But being true
is not enough, since the premises might not be relevant to the conclusion. An argument’s premises must also support the conclusion.
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Logical strength is a matter of degree.
Some arguments are stronger, logically, than others. In other words, some arguments provide more support for the conclusion than others.
Jones stole a watch from the store, so he is a kleptomaniac.
Although the premise provides modest support for the conclusion, this is a very
weak argument.
Jones regularly steals things from store counters, so he is a kleptomaniac.
This is a much stronger argument, but it still does not absolutely prove its conclusion. Perhaps Jones enjoys stealing from store counters.
Jones has been diagnosed with a compulsive disorder that makes
him steal, anyone with that disorder is a kleptomaniac, so he is a
kleptomaniac.
This is the strongest possible kind of argument: for if the premises were true, then
they would guarantee that the conclusion was true too.
An Argument is VALID just in case it is not possible for the premises
to be and the conclusion to be false. In other words, if the premises
were true, then there would be no way the conclusion could be false.
Whether an argument is valid does not depend on whether the premises are
true.
Consider this argument.
The CN Tower is a heavenly body. All heavenly bodies are made of
blue cheese. So, the CN tower is made of blue cheese.
Even though these premises are not true, the argument is valid. This silly example illustrates a serious point: to tell whether an argument’s premises support its
conclusion, it is not enough to know whether its premises are true.
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If an argument consists of independent premises for a conclusion, then the logical relation of each premise to that conclusion needs to be assessed on its own.
Even if the fact that James is squeamish about the sight of blood is not a good
reason for him not to go to medical school, the fact that he dislikes being around
sick people might be a good one. Where there are lots of independent reasons for
some assertion, each reason has to be assessed on its own merits.
IMPLICIT PREMISES
In ordinary life, we often do not explicitly formulate all the premises when we
reason.
Bill Clinton is a man. Therefore, he is mortal.
This is an argument, but it leaves out an important premise. It is obvious what
that premise is.
All men are mortal.
When we add that premise we have an argument that is valid.
A premise that is left out of an argument, is an implicit premise (A.K.A., a hidden
assumption).
Consider the following argument:
Some students are failing French.
Therefore, they are not enjoying it.
What is the implicit premise?
Rule 1: the implicit premise should close the logical gap between the stated
premises and the conclusion. I.e., it should make the argument valid.
2 candidates.
People never enjoy something they find difficult.
Students do not enjoy classes they are failing.
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Both candidates would make the argument valid. But (a) is a much more general
claim than (b), and so contains a lot more information. It is thus a more controversial claim.
Rule 2: the implicit premise should not commit the speaker to more than is necessary. I.e., it should be the least controversial premise that would make the argument logically strong.
So we want to MAXIMIZE logical strength, while MINIMIZING controversy.
This is often a difficult balance to achieve with certainty.
But identifying missing premises is a really helpful step in assessing an argument. For, as we have seen, there are two questions we need to ask in deciding
whether an argument is good: are the premises true, and do they provide sufficient logical support for the conclusion. Disagreements over an argument can
thus take two forms: a disagreement about the truth of the premises or a disagreement over whether the premises really do support the conclusion. Adding
missing premises that make the argument logically strong lets us to focus our attention, in assessing the argument, on whether the premises are true. What is
more, sometimes the missing premise is so implausible that finding it will all by
itself settle the question whether the argument ought to be accepted.
QUIZ
True or false? If you think it is false, give an example to show this.
•1.
If the premises of an argument are false, then they do not support the conclusion.
•2. If an argument has true premises, and a true conclusion, then the argument is
logically strong.
•3. If an argument has a false conclusion, then its premises do not support that
conclusion.
•4. If an argument has true premises and a false conclusion, then its premises do
not support its conclusion.
Text Analysis Answers:
Here are the different assertions in the first argument.
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1. Neither parole nor probation is justifiable.
2. Parole and probation are a demonstrable failure in preventing criminals
from committing further crimes.
3. Parole and probation undermine the deterrent impact of the laws on criminals.
4. Parole and probation demoralize crime victims with their outrageous leniency.
5. Parole and probation jeopardize public safety.
Assertion 1 is the conclusion, and each of 2, 3, 4 and 5 provide independent support for it.
Here are the different assertions in the second argument. Notice that the text was
very repetitive, so I have left out any assertions that were made more than once.
Which ones to leave off is a judgment call, but it gets easier with practice.
1.
2.
3.
4.
5.
The soul is immortal.
The Soul existed before birth
The Soul will continue to exist after death
The Soul is separate from the body
The body dies
In this case, 2 and 3 work together to support assertion 1. They form a subargument for the assertion that the soul is immortal. Assertions 1 and 5 work
dependently to support the primary conclusion, assertion 4, that the Soul is
separate from the body.
Quiz answers:
1. If the premises of an argument are false, then they do not support the conclusion.
FALSE: whether the premises support the conclusion depends only on
whether, if they were true, would the conclusion have to be true too. Not on
whether the premises are in fact true.
2. If an argument has true premises, and a true conclusion, then the argument is
logically strong.
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FALSE: while it is good for an argument to have true premises and a true
conclusion, this is not enough. The premises must also support the conclusion,
and true premises need not support a conclusion.
3. If an argument has a false conclusion, then its premises do not support that
conclusion.
FALSE: while true premises cannot provide logical support for a false
conclusion, false ones can. So, just because an argument has a false conclusion,
this does not yet mean that its premises do not support the conclusion.
4. If an argument has true premises and a false conclusion, then its premises do
not support its conclusion.
TRUE: Premises support a conclusion when it is not possible for the premises to be true and the conclusion to be false. So, if you know that the
premises are true and that the conclusion is false, then you know that the
argument is not valid.
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Chapter 4: Assessing the Evidence
In Chapter 3 we discussed the abstract structure of arguments, reasoning from a
premise or set of premises to a conclusion. But we didn’t say much about the different kinds of premises there are, the different kinds of evidence one might appeal to or seek out in trying to reach a conclusion. In this chapter, we will identify several kinds of premises and discuss under what conditions they are acceptable. We start with claims about meaning, including claims about frameworks,
and then explore the much broader category of claims about the facts.
CLAIMS ABOUT MEANING
There are two kinds of claims about meaning.
Definitions
A definition is a claim about the meaning of a word. In principle, the definition
of a word should specify the essence of what the word names or refers to. The
definition of “apple pie” ought, that is, to say as precisely as possible what makes
something an apple pie. This is a tall order, and a quick glance through any
standard dictionary reveals that this ideal is rarely reached. In practice, we can
identify several lower standards for a definition.
Ideally, a definition should:
1. Provide a rule for being a referent of the word.
A definition of “apple pie” should be a rule for telling whether
something is an apple pie. It should give us insight into deciding,
on a specific occasion, whether the waiter has served what we ordered.
2. Include a genus and a species.
A definition of “apple pie” should say what general kind of thing
the word applies to, and also which specific things of that kind. It
should say, for instance, that an apple pie is a dessert (the genus),
and then specify what sort of dessert it is (the species).
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3. Be neither too broad nor too narrow.
A definition is too broad if it includes things that are not really included in the concept.
“An apple pie is an apple filled dessert.” is too broad,
since it includes apple filled donuts.
A definition is too narrow if it excludes things that are not really
included in the concept.
“An apple pie is a pie shaped apple filled cinnamon
flavored pastry” is too narrow: it excludes things that
really are apple pies, such as the rectangular apple
pies sometimes served at church dinners.
Constructing a definition: the SEE method
A three step method can help in constructing definitions. First, state (S) the definition as clearly as possible in as short a sentence as possible. Next, provide an
elaboration (E), even in a few sentences, by offering definitions of the key terms.
Finally, give an example (E) from real life or a fictional illustration.
If the definition involves several key concepts or terms, it is also helpful to explain how these concepts are related to one another. Does one of them depend on
another, or are they independent of each other? Here, again, examples can be
really helpful.
Here is a sample definition of “knowledge”:
Knowledge is justified true belief. More fully, to know something
is to have an opinion or attitude about the facts that is accurate to
the facts and that is based on adequate evidence. These three elements to knowledge—justification, truth and belief—are independent one form the other. That is, knowledge requires more than
simply having a true belief, since lucky guesses do not yield
knowledge. And knowledge requires more than just a justified belief, since a well grounded belief can nonetheless be false. Ancient
astronomers had good reason to think that the Sun orbited the
earth, but they were still wrong.
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The first part (purple) states the definition succinctly, with both a genus (belief)
and a species (justified and true). The second part elaborates on this statement,
indicating how the three elements (belief, truth, justification) are inter-related.
The final part offers some examples both to illustrate the inter-relations, but also
to illustrate knowledge itself.
An important step in evaluating a proposed definition is looking for counterexamples. A counter-example is a case, either a real one or a fictional one, that
shows that the definition is either too broad (includes things that it should not)
or too narrow (excludes things that it should include). Responding to an alleged
counter-example requires either showing that it is not a genuine counter-example
to the definition or else revising the definition to include/exclude examples of
that kind.
Frameworks
One of the most important tasks in deciding what to believe or to do is to get
clear on the question at hand or on the problem needing to be solved. This is a
matter of framing the issue, or defining the problem. There are almost always
different ways to frame a question or problem, and what framework we adopt is
crucial because a framework determines what alternatives are open to us, what
the key words and phrases are, and what it will take to answer the question or
solve the problem.
In his auto-biography, John Sculley of Apple Computer, describes a classic case
of reframing during his time with Pepsi.1 The problem was how to compete with
Coca-Cola and, more specifically, how to deal with the fact that Coke’s distinctive glass bottle was so well known and loved. For a long time, Pepsi tried one
bottle design after another to no avail. Nothing they tried made a dent in the
huge difference in market share between Pepsi and Coke. Then, after some inspired market research, Pepsi introduced a much larger bottle, containing far
more cola than the classic Coke bottle, and almost overnight Pepsi increased its
market share, nearly eliminating the huge advantage Coke had enjoyed for years.
Because Coke was unable to produce large sized bottles with the traditional look,
and because the competition was now for size, rather than shape, Coke virtually
ended production of its distinctive bottle.
This story shows the importance of properly defining or framing the problem.
The original assumption, shared by both Coke and Pepsi, was that customer pur-
41
chase decisions were based primarily on bottle design. This assumption framed
the problem and determined possible solutions. The goal was to design a bottle
the customers would like best, and the problem is that there are a limited number of possible shapes and no cheap ways to decide which the customers will
prefer. But after carefully studying customer preferences, Pepsi discovered that
customers would choose greater volume over preferred shape. They would buy
a larger volume of Cola even if it was packaged in a container with a less preferable shape. Realizing this, the problem shifted markedly: how to identify and
produce the largest container that customers will buy.
This case also illustrates the subtle interactions between the framework we use to
define a problem (in this case, the best packaging) and factual assumptions (in
this case, customer preferences) about the way the world is. Identifying the factual assumptions that lie behind our frameworks is central to getting clear on the
problems we face, especially when those assumptions are false. This is very important since the framework defines, not just how we see the problem or issue,
but also what would count as a possible solution to it.
The SEE method used to decide on or evaluate a definition can also be used to
decide on or evaluate a framework, since a framework is simply a definition of a
problem, task or challenge. Begin by stating a problem, as simply as possible.
Then elaborate on it by saying more about the key terms and assumptions. Finally, use an example or illustration to make the problem clear.
Compare the following frames for the problem about low employee morale discussed in Chapter 2.
Framework 1: Employee morale is low and we need a plan to raise it. The employees have reported in informal surveys that their work is monotonous and
that they lack the authority to make changes that would increase productivity.
This has resulted in increased sick days and tardiness. We need to assess how we
can best reduce the repetitive nature of the work and devolve decision making to
the line workers.
Framework 2: Employee morale is low and we need a plan to raise it. Our competition has just increased compensation for its workers and our foremen are
hearing rumors that we will not follow suit. There are some reports of our workers seeking interviews with our competition. We need to study our compensation packages.
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From the first sentence statement of the problem, one could not tell what the
problem really is. Subsequent sentences clarify the nature of the problem by
both spelling out what “low morale” means, and the kind of evidence involved
in the claim that morale is low. Notice also how the framing of the problem leads
directly to relevant (and different) suggestions for solutions.
CLAIMS ABOUT MATTERS OF FACT
We have been discussing how to decide on definitions and frameworks. But
most of the claims in an argument are claims about matters of fact, about the way
things are. We can distinguish specific claims from general claims.
Specific Claims
A specific claim is a claim about an individual thing or object, as opposed to a
claim about some kind of thing. For example,
This raven is black
George Bush won the election in 2004
John is six feet tall
are specific claims, because their truth depends on how things are with some
specific object or phenomena. As reflection on these examples make clear, belief
in a specific claim can be justified by or based on evidence from observation, either one’s own or a report of someone else’s observation. The third example is
one where some measurement is needed. Let’s consider each of these sources of
evidence in turn.
Observation
As the first example suggests, belief in specific claims can be justified through
observation, whether one’s own or someone else’s. I might be able to tell
through my own observation that a given raven is black, or I might learn this
from a neighbor who has seen it.
Observation is, in general, a highly reliable source of evidence. Of course, we all
know the kinds of conditions under which it ceases to be reliable. And we know
how to tell whether those conditions obtain. I won’t say more about this here.
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Testimony
More can be said about when we should trust what another person says. In general, it is right to trust the word of another person only when
a. appeal to expert testimony is appropriate.
For some kinds of topics there is no such thing as truth. For instance, there are no experts on matters of taste, or personal preference, such as whether oysters are delicious. Appealing to an expert
on such a matter is inappropriate.
b. the witness is competent.
a. the witness must be properly trained in the relevant field, must
have the needed expertise
b. the witness must have studied the relevant facts of the case,
must be properly informed.
c. the witness must not be biased in any way.
If a belief is based on the word of another person when that appeal is not appropriate, or when the witness is in some way incompetent to know the fact at hand
or is biased in some way, then the belief is not justified. However, this does not
mean that the belief is false. An untrustworthy witness might still speak the
truth.
Measurement
Results of measurement can be assessed along three independent dimensions.
The precision of a measurement is a matter of how discriminating the measuring
instrument is. The accuracy of a measurement is a matter of how good the
measuring instrument is at detecting what it is designed to detect. The reliability of a measurement is a matter of whether repeated uses of the instrument yield
the same result.
To see the difference between precision and accuracy, suppose we have two
bathroom scales. Scale A reports differences in weight as small as ¼ lb., while
Scale B reports only differences in weight as small as 1 lb. But Scale A is not very
well designed and can be off by as much as 2 pounds, while Scale B is quite well
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designed and is almost never off by more than 1 pound. Suppose Jones gets on
the Scale A and it reads 185 3/4 lbs, and then gets on Scale B and it reads 185 lbs.
What should he conclude about his weight?
The reading from Scale A is more precise, since it gives readings down to the ¼
lb. But because it could be off by as much as 2 lbs, all that Jones can conclude
from what Scale A tells him is that he weighs something between 183 ¾ and 187
¾. Because Scale B is very accurate, even though it is not as precise, he can conclude from its reading that he weighs something between 184 and 186.
This example shows that even though Scale A is a much more precise measuring
instrument than Scale B, because it is not as accurate as Scale B, measurement
made using it are far less informative. The general lesson here is simply that we
must be on our guard not to trust a more precise measurement just because it is
more precise. We also need to consider how accurate the measurement is. Usually, accuracy is more important than precision.
Of course, reliability is an important factor too. The bathroom scale at my house,
for instance, is not very reliable at all: by leaning forward on it, or by waiting a
few moments, one can drop a couple of pounds. An unreliable scale is necessarily not very accurate. But reliability is not the same as accuracy, since an inaccurate scale might always give the same inaccurate measurement. So, it is important not to confuse reliability (giving the same measurement) with accuracy
(giving the right measurement.) Again, it is accuracy we want in a measuring
instrument, and it is important not to confuse accuracy and reliability.
The distinctions between accuracy, precision and reliability apply to opinion
polls too. We are sometimes told, for instance, that 45.5% of the population has
some attitude towards some policy or other. This is a very precise result, since it
reports differences in tenth’s of a percent. But, as we also know, polling results
can have a very large “margin of error”, sometimes 2 or 3 percentage points. So,
a poll with that kind of margin of error is not very accurate even though it is
quite precise. What is more, there are significant questions about the reliability
of polls: do they yield the same results every time the questions are asked, or
when the question is worded slightly differently? Here, as with Jones and the
morning scale, it is accuracy that we care about most, and we need to be careful
not to confuse accuracy with either precision or reliability, even though both precision and reliability are important.
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A final issue to keep in mind in the case of measurement is measurement bias.
Measurement accuracy can be affected by the biases of both the measurer and,
especially when humans are being measured, the thing measured. We all have a
natural tendency to privilege confirming evidence over evidence that runs counter to what we believe or want to be true, and this tendency affects our attempts
to measure: we tend to over assess the accuracy of measurements that confirm
our beliefs or hypotheses and discount the accuracy of disconfirming measurements. And when we know that we or our attitudes are being measured we tend
to adjust them, or at least our expressions of them, to yield the measurements we
want (or we think the measurer wants). Children always stand on their toes at
the doctor’s office when their height is measured, and blood pressure readings
tend to be higher in the doctor’s office than at home.
Pharmaceutical tests are an interesting case involving measurement bias. It is
well known that subjects and researchers involved in pharmaceutical tests tend
to downplay or misreport their symptoms if they believe they or the subject are
receiving the medicine as opposed to the placebo. To correct for this, pharmaceutical tests need to be double-blind: neither the researcher nor the subjects
knows who is receiving the placebo until after the study is completed and “code”
is broken. By eliminating the risk of measurement bias, this increases the likelihood of objective descriptions of the symptoms and so more accurate assessments of the medicine’s effectiveness.
General Claims
A general claim is a claim whose truth depends on how things are with a group
or category of things, and not just with any one member of that category. The
following are examples of general claims.
All ravens are black
Vitamin C reduces cancer risk
The average basketball player is 7 feet tall.
And these examples point to the range of different kinds of general claims, or
generalizations. The first is a categorical generalization; the second a causal generalization; and the third is an averaging generalization. Let’s consider each
kind in turn.
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Categorical Generalizations
A categorical generalization is one that relates two categories or classes of things.
There are four broad kinds of categorical generalizations, and we can refer to
each of them using a letter of the alphabet.
A
E
I
O
All As are Bs
No As are Bs
Some As are Bs
Some As are not Bs
The words “All”, “Some”, “No” are Quantifiers, since they specify how much of
the subject class is said to be included in the predicate class. Of course, in English we have lots of additional quantifiers: “most”, “a large number”, “85%”,
“few”. Even our numerals, like “65” and “2005” can be used as quantifiers. But
for our purposes, we can restrict attention to “all”, “some” and “no”.
It is very important to be clear about the logical relations among categorical generalizations. Suppose that the following A generalization is true.
A
All Ss are Ps
What does the truth of this show about the truth of the following:
E
I
O
No Ss are Ps
Some Ss are Ps
Some Ss are not Ps
It shows that the E and the O generalizations must be false, and that the I generalization must be true. If all of the Ss are Ps, then it cannot be true that none of
them are or even that some of them are not, but it must be true that some of them
are.
But what if we instead knew that the A was false? What could we then conclude
about the other three generalizations? Here we can not conclude nearly as much.
In fact, the only thing we can know for sure is that the O is true. If we know that
not all of the Ss are Ps, then this must be because some of the Ss are not Ps, which
is what the O generalization says. But this does not mean that none of the Ss are
Ps, as the E generalization states, since perhaps some of them are. But it also
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does not show that some of the Ss are Ps, as the I generalization states, since, for
all we know, none of them are.
We can prove this to ourselves by considering English language examples of a
false A.
All cats are male.
Clearly, in this case, the O (“Some cats are not male”) is true. But the E (“No cats
are male”) is false too. And the I (“Some cats are male”) is true. But consider this
different example.
All men are immortal.
As before, the O is true. But this time, the E is true too, and the I is false. This
shows that you cannot conclude with certainty, just from the fact that an A generalization is false, anything about the corresponding E or I propositions, though
you can tell with certainty that the corresponding O is true.
The logical relations among categorical generalizations are subtle. We can summarize them in the following way.
Contraries: A and E are contraries of each other, at least one must be false, but
both could be false.
Sub-Contraries: I and O are sub-contraries of each other: at least one must be
true, but both could be true.
Homework: find an English language example of a true I where
the corresponding O is false, and then vice-versa.
Contradictories: A and O are contradictories, as are E and I. Contradictory generalizations always have opposite truth values: if one is true,
the other has got to be false.
Alternates: A and I are alternates, as are E and O. Truth flows with certainty only from A to I and from E to O, but not from I to A or from O
to E. But falsity flows with certainty from I to A and from O
to E.
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Knowing the logical relations among these categorical generalizations can help
us to avoid drawing some hasty generalizations.
1. Concluding from the falsity of A to the truth of E.
This can happen when one confuses “Not all” and “All are not”.
To say that not all Ss are Ps is not the same as saying that all the Ss
are not Ps, that is, that no Ss are Ps. In fact, even if not all of the Ss
are Ps, this does not show that none of them are.
“Not all” is a way of saying that an A generalization is false. But, as
we just learned, this does not prove that the corresponding E generalization is true. It might be false too.
Homework: think of three examples of a false A where the corresponding E is also false?
2. Concluding from the truth of an I to the truth of the corresponding O, or
vice-versa.
This happens because in ordinary life, when someone says that
some Ss are Ps, we assume that they are not sure whether all of
them are, since if they were sure then they would have so. So we
conclude from what they said that some Ss are not Ps. This little inference we draw is not justified by the logical relations between I
and O, but by additional information we have about what people
would say.
But we know from the logic that it is a mistake to conclude, just
from the fact that some I is true, that the corresponding O is true
too (and vice-versa).
3. Concluding from the truth of an I to that of the A, or from the truth of an
O to that of the E.
It is clear when it is appropriate to believe that some Ss are Ps, or
that some are not. So long as you know of one S that is (or is not) P,
then you know that some Ss are Ps (or are not). But it is not nearly
so clear when it is appropriate to believe that all the Ss are Ps, or
that none of them are. In fact, there is no recognized method, short
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of checking every last S, of knowing with certainty whether all of
them, or none of them, are P.
The rule of thumb is: be cautious before concluding anything about
all the Ss.
Causal Generalizations
A causal generalization is a claim about the cause of some phenomena. For instance, the following are causal generalizations.
Motrin relieves headaches
Vitamin C helps to prevent cancer.
Inflation causes unemployment
We do make claims about specific causal events, such as that the Motrin I took
relieved my headache. But the truth of such specific causal claims always relies
on the truth of some general causal claim, such as that Motrin relieves headaches.
So we can restrict our attention here to general causal claims.
Unfortunately, the word “cause” is ambiguous in English. To say “X causes Y”
can mean several different things:
Sufficient condition: X is enough to make Y happen:
Drowning causes death.
Drowning is not the only of death, but it is enough to cause death. So
drowning is a sufficient cause of death.
Necessary condition: Y would not have happened if X had not
Watering makes your lawn grow.
Water is not all that a lawn needs to grow. Sunshine and nutrients are also
needed. But without water, the lawn will die. So, watering is a necessary
cause for lawn growth.
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Whenever some event or phenomena occurs, some set of conditions sufficient for
it to occur must have been present, and that set must include all the conditions
necessary for it to occur.
How to identify a necessary cause: one can try to identify an effect’s necessary
cause by comparing cases where the effect is present. The idea is that whatever
is necessary for the effect must be present whenever the effect is present. So, to
find the necessary cause, look for the common factor.
After eating lunch at the same restaurant, five individuals became
ill with hepatitis. What caused the illness? Inspectors from the
Health Department learned that while the five individuals had eaten different meals, they had all eaten tomatoes in their salad. Furthermore, this was the only food that they had all eaten. So, the inspectors concluded, the tomatoes had probably caused the hepatitis
infection.
This reasoning supports only the conclusion that eating the tomatoes was a necessary cause of the illness, not that it was a sufficient cause. It does not show that
other factors were not involved. Maybe the tomatoes together with something
else were together sufficient. The most we can conclude using this method is
that the tomatoes are part of the story, not that they are the whole story.
Moreover, the conclusion is only probable for several reasons.
Overlooked causes: Perhaps there was an infected utensil that was used only
for the salads of those who were infected. Because there are always so many different factors present in any series of cases, there can be no guarantee that one
has identified all the necessary ones.
Multiple causes: perhaps both the potatoes and the liver were infected, and
not the tomatoes, and that those who were infected ate either the potatoes or the
liver, and that the fact that they all ate the tomatoes is a coincidence. This method, of finding what is in common across many cases works only if the same cause
is responsible in each case. Whether this is so is something we need to find out,
not something we can assume.
Overlooked effects: the method works only if one really has identified all the
cases where the effect is present. Maybe someone who got sick did not report it,
and was not included in the study, and perhaps that person did not have the to51
matoes. This would show that eating the tomatoes was not a necessary cause at
all.
How to identify a sufficient cause: one can try to identify a sufficient cause by
comparing cases where the effect is missing. The idea is that any of the effect’s
sufficient causes will be missing whenever the effect is missing. So whatever is
present when the effect is present and missing when the effect is missing will be
sufficient.
After conducting a study on the work force at a certain factory, engineers found that 5 workers performed their task less efficiently
than the others. A list was made of the various factors that were
present and absent in the employment conditions of these five
workers. It was discovered that among 8 likely candidates, only
one factor was missing for all 5: they all complained about not getting any share of the profits. So, the engineers concluded that having a share in the profits makes workers highly efficient.
This reasoning supports only the conclusion that profit-sharing is one way to increase worker efficiency, not that it is the only way. It reveals at most that profit
sharing is a sufficient cause, not that it is a necessary cause. What is more, and as
before, the conclusion is only probable since they might have overlooked other
conditions that were also missing when the effect was missing, there might have
been multiple causes in this case, and cases when the condition was missing and
the effect was present might have been overlooked.
The discussion so far shows just how difficult it is to reason well about causes.
Unfortunately, matters are even more complicated. For a factor might be a necessary part of a sufficient cause of some effect, without being on its own either
necessary or sufficient for the effect. Being infected with HIV is not itself sufficient to kill, since there are (it seems) infected people who never develops AIDS.
But being HIV-positive is part of a sufficient condition for death, since it together
with whatever leads to full blown AIDS is fatal. Of course, having HIV is not
necessary for death, since there are lots of other causes of death too. So, being
infected with HIV is a necessary but not sufficient factor in a sufficient but not
necessary cause of death. Got it?
Necessary and sufficient causes.
The following example illustrates how we can combines both these strategies to
try to identify conditions are that individually necessary and jointly sufficient.
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Eight inhabitants of a town contract a rare form of the plague. A
doctor flies to the town with a serum she thinks might be a cure.
Only 4 of the inhabitants accept the cure, the other 4 insist on using
home remedies. But all eight had been treated with home remedies
before the doctor arrived. Eventually, the 4 who received the serum
recovered, while the other 4 died. What had caused the recovery?
The Doctor noticed that among those who survived, no single
home remedy was given to all; and that each home remedy had
been given to at least one of those who did not survive. The Doctor
concluded that the serum caused the recovery.
Here the Doctor’s conclusion is that the serum is necessary for a cure (since it
was present every time the cure was present) and sufficient too (since it was absent every time the cure was absent.) As before, though, this conclusion is only
probable, for all the reasons we have noted.
Designing an experiment to identify a cause.
Suppose you want to figure out what causes some phenomena, P. The first thing
you need to do is make a list of possible causes. You then have to design an experiment that will show, for each possible cause, whether it is necessary or sufficient. It is very important that only one possible cause be tested at a time. That
is, you need to vary only that one condition. In other words, you must control
for variations in the other conditions. If your initial hypotheses were right, and if
your experiment was well designed, then you will discover a cause. If not, then
you have to reconsider either the hypotheses or the experimental design.
Homework:
1. Suppose you wanted to discover what causal conditions are responsible for the growth
of a tomato plant. Design an experiment that would reveal what conditions are necessary
and sufficient. Explain how the experiment’s design would reveal each kind of cause.
Be aware of assumptions you make as you design the experiment, especially when you
list the possible necessary and sufficient causes!
2. Design an experiment to test whether ingesting vitamin C prevents the common cold.
List the specific reasons why the results of the experiment constitute only probabilistic
evidence for the conclusion that vitamin C does, or does not, prevent the common cold.
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Averaging Generalizations
An averaging generalization is one that makes a claim about the average or typical member of some group or class.
Typical ravens are black.
Our average customer is from the mid-west.
Sometimes, we formulate averaging generalizations in the way we formulate ordinary generalizations: we say “Bachelors love to party” which sounds like it
might mean the same as “All bachelors love to party”, but could also mean something more like “The average bachelor loves to party.” Figuring out whether the
speaker has a categorical generalization or an averaging generalization in mind
can be hard.
Reasoning using averaging generalizations is tricky simply because there are so
many ways of finding a so-called “average”, and some are more informative than
others for certain decisions. I’ll start by identifying the three basic kinds of “averages”, and then discuss some examples.
Let’s suppose that 20 people shopped at Super Saver one day and that this how
much they each spent.
1 spent 5 dollars
6 spent 20 dollars
8 spent 57 dollars
3 spent 89 dollars
2 spent 175 dollars
One might reasonably ask: what was the average purchase that day?
To find the mean purchase, divide the total dollars spent by the number of shoppers. In this case, the mean is $73.90.
To find the median purchase, find the number of dollars spent such that half of
the shoppers spent more. In this case, the median is $57.
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To find the mode purchase, find the number of dollars most frequently spent. In
this case, the mode is $87, since more shoppers spent that much than spent any
other amount.
The three measures are independent of one another and are sensitive to different
kinds of factors. The mean, but not the mode or median, is sensitive to highs and
lows. If one of the shoppers has spent $350 instead of $175 that day, the mean
would have been $87.64, but neither the median nor the mode would have
changed.
The median, but not necessarily the mean or the mode, is sensitive to the numbers of shoppers in a given range. The median would have been lower had more
shoppers spent less than $57. But so long as these low spenders spent different
amounts, the mode of $87 would have been the same. And if the high spenders
had at the same time spent a lot more, to make up for the increased number of
low spenders, the mean would have been the same.
So what was the average purchase that day? Well, there is no univocal answer to
this question. Here are the facts:
Half the shoppers spent less than $57.
The purchase per shopper was almost $74.
More shoppers spent 87 than any other amount.
Once we have made the questions about averages more precise by distinguishing
different kinds of averages, it makes no sense to continue to ask about the average purchase.
An especially striking example of an error in reasoning about averages occurred
during the run-up to the ill-fated Challenger space shuttle flight. The explosion
of the space shuttle was caused by a failing o-ring, and it was well known to
NASA’s engineers that the rings could fail under certain temperature conditions.
By studying past cases of damage to the rings, they had discovered that most of
the cases of damage occurred at or above 60 degrees, and that only a few cases
occurred at lower temperatures. They concluded from this that the risk of damage was greater at higher temperatures. On the basis of this, they had decided
that the risk to the Challenger was minimal on launch day, which was a cool day.
Unfortunately, this conclusion does not follow. Only after the disaster, when
they did further studies, did they look at cases where there had been no damage
to the o-rings. They discovered that most of the space shuttle trips at or above 60
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degrees involved no damage to the o-rings at all, and that every trip at temperatures below 60 degree did involve damage.
In effect, the engineers had failed to heed the difference between the following
averages.
The average temperature in cases of damage.
The average damage at different temperatures.
The second average is what they needed to know in trying to determine the relative risk of launching the shuttle at various temperatures. And to figure this out,
they needed to examine case where there was no damage, as well as cases of
damage. Perhaps their understandable focus on damaged o-rings, as opposed to
undamaged ones, prevented them from properly framing the problem.2
Homework:
Home Value: Several houses in your neighborhood, many of which are comparable to your house, but some of which have many more updates, have sold recently. You would like to use these sales prices to figure out the value of your
house. Which kind of average should you look at? Why?
Sales Predictions: You have six months worth of monthly sales receipts for the
20 salespeople on your team. Which average would you look at, and why, in order to:
Calculate the anticipated total sales for next month?
Establish a uniform expected sales goal for your sales force?
Tax Cut Benefits: The government proposes to cut taxes and announces that the
average tax cut will be $800. Explain the different ways this announcement
might mislead someone who is not sophisticated about averages.
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Chapter 5: Drawing Conclusions from the Evidence
In Chapter 4, we considered several different kinds of evidence, and discussed
when evidence of that kind is trustworthy. Now we can consider how one
should draw conclusions from that evidence. We will examine three forms of
reasoning, forms that can be applied to reasoning about any subject matter at all:
reasoning about alternatives, conditional reasoning, and reasoning by analogy.
REASONING ABOUT ALTERNATIVES
Reasoning about alternatives is a matter of ruling out possibilities until only one
remains. As Sherlock Holmes described it: elementary. Still, it is worth saying a
bit about some of the tricks involved.
Reasoning about alternatives takes the following form:
Either P or Q is true
P is not true
So: Q must be true.
After introducing some terminology, well consider some facts about meaning,
and then discuss when such reasoning is logically sound.
In a disjunctive statement
P or Q
“P” and “Q” are called the disjuncts. Note that a disjunctive statement asserts neither disjunct. If you said:
either it will rain or it will be sunny,
you would not be asserting that it will rain and you would not be asserting that it
will be sunny. In fact, you may not know which of them is true. But in using
that sentence, you would be asserting that there is a relation between the disjuncts: that at least one of them is true.
“P or Q” is true just in case at least one of the disjuncts is true.
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Suppose that you discovered that one of the disjuncts was not true. In that case,
you could conclude that the other one was true, since you are claiming that one
of them is true. The following argument, denying a disjunct, is thus a valid one.
P or Q
Not-P
Therefore, Q
To say that an argument is valid is simply to say that its premises provide the
strongest possible kind of logical support for the conclusion. In other words, in a
valid argument, if the premises are true the conclusion would have to be true to.
A common mistake in reasoning about alternatives is to instead affirm a disjunct.
Either P or Q.
P____________
Therefore, not-Q.
This is reasoning from the fact that some disjunct is true to the conclusion that
the other disjunct is not true. This is not a valid form of reasoning.
But the issue is a bit subtle, since sometimes we use the word “or” in a special
way. The inclusive sense of “or” says that at least one disjunct is true. The exclusive sense of “or” says that at least one but only one disjunct is true.
Her new baby is a boy or her new baby is a girl.
But it is not a boy
So, it must be a girl
Typically, in using the first premise of this argument, one would be saying that
one but only one of the disjuncts is true. But this is partly because you would be
taking it for granted that no baby can be both a girl and a boy. In other words, in
using these sentences to say those things, you would in effect be relying on a
hidden assumption. In reasoning, it is always better to make hidden assumptions explicit.
Her new baby is a boy or her new baby is a girl.
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If her baby is a boy, then it is not a girl; and if her baby ids a girl, then it is
not a boy.
But it is not a boy
So, it must be a girl
Adding this implicit premise makes the argument valid. But it is now no longer
a straightforward case of ruling out alternatives. In fact, it is now a mixture of
both reasoning about alternatives and conditional reasoning. So, let’s discuss
conditional reasoning a bit and then return to this example.
CONDITIONAL REASONING
Conditional reasoning, like reasoning about alternatives, is a very common form
of reasoning and can be applied to any subject matter. It is reasoning involving a
conditional, a statement like the following
If P, then Q
In a conditional, “P” is called the antecedent, and “Q” is called the consequent.
In a hypothetical statement we do not assert either the antecedent or the consequent. Instead, we assert that a relation holds between them: that it is not the
case that the antecedent is true and the consequent is false. Suppose one said:
If Jones did it, then he should be jailed.
One would not be saying that Jones did do it, let alone that he should be jailed.
To get clearer on what we would be saying, we need to consider the distinction
between necessary and sufficient conditions.
A conditional claims that the truth of the antecedent is sufficient for the truth of
the consequent. That is, it claims that the truth of the antecedent would be
enough for the consequent to be true too.
If you get an A in the class, then you will pass.
This conditional says that getting an A is one way to pass the course. It does not
claim that it is the only way. But neither does it claim that there is some other
way. It is simply neutral on whether there are other ways to pass the course.
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A conditional also claims that the truth of the consequent is necessary for the
truth of the antecedent. Our example conditional says that to get an A in the
course you have to pass it. This seems right, even if that is an odd way to put it.
A more natural way to put the idea that passing is necessary for getting an A
would be the following.
You get an A in the class only if you pass it.
But, in fact, these are probably just two ways of saying the same thing.
There are, unfortunately, lots of different ways in English of making a claim
about necessary and sufficient conditions. An important one is the following:
P unless Q
Jones will be jailed, unless he surrenders.
In using this sentence one would be saying that the only way for Jones to avoid
being jailed is for him to surrender. In other words, if he does not surrender,
then he will be jailed.
If not-Q, then P
If Jones does not surrender, then he will be jailed.
Now that we have considered the meaning of conditionals, and some of the different ways we have in English of formulating them, let’s turn to reasoning with
them. There are three valid forms of the Hypothetical Syllogism.
Pure Hypothetical Syllogism:
If P, then Q.
If Q, then R.
If P, then R.
If Jones is a bachelor, then he is a man.
If Jones is a man, then he is mortal.
If Jones is a bachelor, then he is mortal.
Modus Ponens:
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If P, then Q.
P_________
Q
If Jones is a bachelor then he is a man.
Jones is a bachelor.
Jones is a man.
Modus Tollens:
If P, then Q
Not-Q_____
Not-P
If Jones is a bachelor then he is a man.
Jones is not a man.
Jones is not a bachelor.
It is also worth noting two forms that are not valid.
Denying the antecedent:
If P, then Q.
Not-P
Not Q.
If Jones is a bachelor, then he is a man.
Jones is not a bachelor.
Jones is not a man.
Affirming the consequent:
If P, then Q
Q________
P
If Jones is a bachelor, then he is a man.
Jones is a man.
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Jones is a bachelor.
REASONING WITH ANALOGIES
We reason using analogies in two ways. We use specific analogies when we draw
a conclusion about some specific phenomena by comparing it to some other specific phenomena. We use model analogies when we draw a conclusion about
some specific phenomena by comparing it to some abstract model of that kind of
phenomena.
Both kinds of analogies involve a comparison of cases, events, phenomena, objects, or etc.
Case A has attributes a, b, c, and z.
Case B also has attributes a, b, and c.
So, Entity B also (probably) has attribute Z.
The conclusion is supposed to be supported by the fact that A and B are analogous— or similar— in relevant respects.
The last time productivity levels dropped this quickly, they rose
again pretty quickly on their own.
So, probably productivity levels will rise again shortly.
When I am in pain, I wince, scream and say “Ow!”
Jones is wincing, screaming and saying “Ow!”
So, Jones is probably in pain.
Inflation is creeping up.
In our economic models, creeping inflation is followed by
creeping unemployment.
So, we will probably see creeping unemployment..
Reasoning by analogy is often a very effective way to defend a conclusion, but it
has important limits. All that an argument by analogy can show is that the conclusion is probably true. The reason is simply that there is no guarantee that the
compared cases really are analogous in every relevant respect.
While the basic logic of reasoning by analogy is the same with both specific and
model analogies, it is helpful to consider them separately.
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Specific Analogies
Specific analogies involve drawing a conclusion about some specific phenomena
by comparing it to some other specific phenomena. There are several principles
we should keep in mind when evaluating whether a specific analogy gives us
good reason to accept its conclusion.
1. Relevance of the similarities. The more relevant the similarities are, the stronger
the argument.
If the relevant conditions present last time productivity fell suddenly are also
present now, then the stronger the analogy. If, however, there are important differences in the two occurrences, then the analogy is weaker.
2. Number of similarities. The greater the number of relevant similarities, the
stronger the analogy.
If the only relevant similarity is that employee morale was low, then this is a
weak analogy. If, however, in both cases morale was low, absenteeism was high,
repair times were longer than unusual, and etc., then the analogy is stronger.
3. Nature and degree of dissimilarity. The fewer the number of relevant dissimilarities the stronger the analogy.
Any two cases are bound to be dissimilar in some ways. Even if there are lots of
relevant similarities, if there are also lots of relevant dissimilarities, then this will
weaken the analogy.
4. Specificity of the conclusion. The stronger the conclusion, the weaker the argument.
In general, it is harder to prove more than to prove less, and this holds true with
analogies too. Concluding that productivity will rise by 3 points is stronger than
claiming it will simply rise by some amount.
Parts and wholes
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Two related kinds of reasoning by analogy involve drawing a conclusion about a
thing from a claim about its parts, and vice-versa. This is a very common kind of
reasoning, regularly exploited in advertising. Foods are often said to be healthy
solely on the basis of the fact that they contain minerals and vitamins which are
themselves healthy. While it is true that the minerals and vitamins in a food are
healthy, it does not follow that the food itself is healthy. Donuts loaded with vitamin C are nonetheless on balance unhealthy, because of their high fat and sugar
contents. Conversely, a food that is on balance healthy might well contain unhealthy constituents. So, you can’t know just from the fact that a thing has some
property that each of its components has that property too or vice-versa. Each
case must be settled on its own merits.
Homework: think of an example where the inference from a part to a whole is
justified, and one where it is not.
Analogy and the law
Our legal system relies on arguments by analogy. Similar cases should be treated similarly. Current cases should be treated in the way as earlier similar cases.
If a case is decided a certain way, then future cases that are relevantly similar
should also be decided that way. Many of our laws are actually rulings by judges in actual cases. These decisions constitute the common law, and serve as precedents for deciding future cases.
In defending an accused person, the defense lawyer will try to find past cases
that are similar to the current case, in which the accused person was found not
guilty. Likewise, the prosecutors will try to find past cases that are similar in
which the accused person was found guilty. A past case which is similar to the
current one in all relevant respects, and not dissimilar in any relevant respect, is
said to be on point.
Model Analogies
Reasoning using models is very common in science. A scientist tries to understand a complex phenomena, the weather or planetary motion, by developing a
model of the phenomena. The model might be an actual physical model, but it is
more likely to be a description of the phenomena. Typically, the description is
mathematical: the relations among the elements in the phenomena are described
in mathematical terms.
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In developing the model, the researcher abstracts away from some of the complexity, and this abstraction underlies both the power and the limits of reasoning
by models. Abstracting away is the same as ignoring for the sake of the inquiry.
When scientists model the motion of the planets in our solar system, they might
ignore the gravitational effects of distant stars, because such effects are relatively
small. This enables them to develop a simplified description of the motion of our
solar system, a description that still works well enough to predict and describe
the future locations of, say, Mars. This simplicity is the great power of reasoning
using models.
The great limit is that because some elements are ignored, the description and
the explanation cannot be complete. The researcher who ignores the gravitational
effects of distant stars knows that they have some effect, and so knows that her
description of our solar system is incomplete. But, so long as she remains aware
of this limit, the benefits of an abstract model outweigh its risks. In designing a
model, we need to be careful about what elements we ignore as we abstract away
from some of the known complexity.
But finding that the model does not fit right is a way of discovering what the relevant elements are, or even of discovering previously unknown elements. A retail business might, for instance, try to develop a model of a typical customer,
one that captures the typical shopper’s financial and educational background or
where they live in the region. The model might provide very useful information
for marketing, inventory and sales decisions. It would, of course, be wrong to
think that everyone fitting that model is a customer (though they may all be potential customers) and just as wrong to think that anyone not fitting the model is
not a potential customer. The model is used as an analogy, and it can be of great
use so long as it does not become confused for a definition.
A business plan is another a kind of model, designed at an abstract level, ignoring a lot of the details of day to day operations. Reasoning about goals and
measuring success using a business plan is reasoning by analogy using a model.
Any business plan must abstract away from some of the complexity that will
pervade its normal operations. It provides a model of how the business should
run. And like a scientific model of the solar system, testing the model against
reality can illuminate the reality itself, bringing to the surface hidden features of
the business, but even more interestingly, testing the model against reality can
bring to the surface hidden assumptions that lead to development of the model
itself.
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Chapter 6: Reasoning about Values
We have been discussing mostly reasoning about matters of fact, reasoning
aimed at deciding what to believe about the world around us. But a good deal of
our ordinary reasoning is aimed at deciding what to do, and this often involves a
mix of decisions about what to believe and what to value. In this Chapter, I will
discuss some of the elements involved in reasoning about values.
THE MEANING OF “OUGHT” STATEMENTS
Our interest is with the connection between values and action. Our values determine what we are required, permitted or forbidden from doing. Any action
that is required is also permitted. And any action that is forbidden is not permitted. But an action can be permitted but not required.
Actions that are required by our values are typically expressed using an “ought”
statement, like the following.
One ought to pay taxes.
One ought to exercise three times a week.
One ought to tell the truth.
But as these examples make clear, there are many different kinds of things we
mean when we say what someone ought to do, different kinds of “ought” statements. In effect, there are different kinds of values.
Prudential. A prudential obligation is an action that is required in order to maintain one’s health or wealth.
Legal. A legal obligation is an action that is required in order to obey the law.
Moral. A moral obligation is an action that is required in order to do one’s moral
duty.
It is important to notice that these three kinds of values are independent one
form the others. That is, an action could be required by the law and prudent
while being morally wrong. For instance, restaurant owners were legally forbidden from serving African Americans in certain southern states in the middle of
the last century, and obeying this law was the prudent thing to do since they
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otherwise were at risk of losing their business. However, we can now see that
this was morally the wrong thing to do.
Homework: describe an action that is:
Morally required, but legally wrong.
Legally required, but imprudent.
WHAT MAKES AN OBLIGATION BINDING?
As we have seen, there are different kinds of “ought” statements, reflecting the
fact that there are different kinds of values. In certain cases, it is pretty clear
what makes “ought” statements binding, that is, what makes us subject to them,
but in other cases, the matter is not very clear at all.
Legal obligations derive from the relevant laws and statutes. What legal obligations one has depends on what laws are in force in one’s community. Though
laws can and do change over time, whether one is subject to a law is not a matter
of decision. It is not up to me whether I am required to file my taxes, even if it is
up to me whether I do file them. Legal obligations bind unconditionally.
Prudential obligations are different. What it takes to maintain or enhance my
health and wealth depends on the facts, of course. As we know, being healthy
requires eating properly and exercising regularly. But unless I care about my
health and wealth I have no obligations to do what prudence requires of me.
Prudential obligations only bind me if I want to be healthy and wealthy, if being
healthy and wealthy is something I value. Prudential obligations bind conditionally.
What about moral obligations? Do they bind us unconditionally, like legal obligations, or only conditionally, like prudential obligations? One traditional answer is that moral obligations bind us absolutely, whether we want them to or
not. But whereas it is clear what the source if our legal and prudential obligations is, it is not so clear what the source is of moral obligations. This makes it
difficult to know just what moral obligations we in fact have. But it is hard to see
how moral obligations, whatever their source, might bind only conditionally. If
lying really is morally forbidden, then presumably it is forbidden for everyone,
and not just for those of us who value being morally good. At least, this is what
traditional conceptions of morality have held.
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It is important not to confuse the question whether moral obligation bind unconditionally with the question whether our moral obligations vary from case to
case. Consider lying. Most us would agree that lying to a police officer is morally wrong, and not just illegal. But what about lying to someone in order to prevent a murder? What if lying to Jones would stop him from killing our children?
Would lying be morally wrong in that case? I suspect most us would say that lying to Jones would be morally permitted (or even morally required). What does
this show us about the nature of moral obligations?
It shows us, I think, that whether telling a lie is morally wrong can depend on
facts about the case. In particular, it can depend on whether the lie would prevent something even worse from happening. If this is right, then what our moral
obligations are may vary from one situation to another.
But even if this is right, this would not show that moral obligations are conditional in any way. Our moral obligations might apply whether we want them to
or not, whether we care about being morally good or not, even if what moral obligations we have vary from one situation to another.
RESOLVING CONFLICTING OBLIGATIONS
We have been discussing different kinds of obligations and the different ways
they can bind us. Sometimes our obligations conflict. What are we to do when
our obligations point in different directions, when we have an obligation to both
do and refrain from doing some action? How can we resolve conflicting obligations?
There are different kinds of conflict. In the case of competing values, both values
can be pursued at once, but the conflict is that in pursuing both, one will end up
with less of each than one would have had one pursued only one value. Being
honest might compete with being kind. When a friend asks our opinion about a
decision they have made, we want to be honest with them, but we also want to
be kind, and so avoid causing them pain. How can we resolve this conflict?
We can, of course, be honest with them in a kind way, and it might be that telling
them the truth will make them happier in the long run, even if it does bring temporary pain, and that being kind requires looking out for our friend’s longer
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term well being. In this case, there would be no real conflict, being kind and being honest both require that one say what one believes.
But it might be that the more honest we are the less kind we are, and vice-versa.
It is not that we have to choose between honesty and kindness, since we could
pursue both at once. The conflict, though, is that we have to find a balance that
maximizes both. This is the Maxi-Max strategy.
Values can also conflict by being contrary. In some cases of conflict, one cannot
pursue both values at once: pursuing one requires sacrificing the other to some
extent. This kind of dilemma is familiar from non-moral cases. An organization
might value both employee morale and productivity. And it may face a situation
where it has to sacrifice one for the other, where it can either enhance morale or
enhance productivity, but not both. In such a case, the problem is to decide how
to order one’s values.
One strategy in this kind of case is to compare different Maxi-Min balances. A
maxi-min balance is an action that maximizes the one value while minimizing
the sacrifice required of the other. There are always, in such cases, two balances,
since there are two values that could be sacrificed. What is the maximum increase in morale we could achieve with the least harm to morale, and what is the
maximum increase in morale with the least harm to productivity? Once those
two balance points have been found, one can compare them and decide which
trade-off, which balance, is the best.
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Chapter 7: Assessing and Constructing Arguments
Now that we have discussed the value of critical thinking, and described the
methods, tools and techniques required for being a critical thinker, we can step
back and provide a summary of how a skilled critical thinker approaches the task
of evaluating or constructing a proposed decision. Not surprisingly, the tasks
are the same whether one is constructing and presenting a decision of one’s own
or whether one is assessing and evaluating a decision proposed by someone else.
CLARIFY MEANING
It is very important to be sure that the proposed decision, whether your own or
another’s, is as clear as possible. In Chapter 4, we discussed how to assess and
evaluate definitions of terms. Those skills apply equally to defining the problem
the decision is meant to address. So long as there is room for disagreement about
what the problem is, or about what the proposed solution is, there can be no lasting and widespread agreement on the decision itself.
If reasons are being presented to support the decision, as they must be if you are
the one presenting a proposed decision, then make sure those are clear too.
Here are some questions to keep in mind:
1.
2.
3.
4.
Are any of the words used ambiguous or unclear?
Can I give a definition of the key words?
Can I provide examples and counter-examples?
Have I carefully distinguished claims about what the belief means from
claims about whether it is true?
5. Can I clearly and precisely state how the world would be if the belief were
true, or if we did what the decision would require us to do?
Frames
It is just as important to make sure that the problem at issue has been properly
defined, and this is a matter of framing it properly. I described a framing problem involving Pepsi and Coca-Cola in chapter 3. But they occur in lots of contexts.
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When I was a child, my family lived in the north of England, and my father, born
and raised in Canada, was intrigued by the fact that so many of the houses had
their water and plumbing pipes running up the outside, exposed to the freezing
cold. Of course, to no one’s surprise, these pipes regularly froze during the winter causing huge inconvenience and requiring costly repairs. When my father
asked his landlord why houses were built this way, the reply was immediate:
when the pipes are on the outside they are easy to access when they freeze. I
have laughed at this story for years, but only recently did I realize that it illustrates perfectly the importance of properly framing a problem.
The unusual building practice was designed to solve a problem: how to access
frozen pipes. If you think of the problem in that way, then their building solution makes good sense, since it is much easier to access pipes when they are on
the outside rather than built inside walls. But, at least from a Canadian’s perspective, accessing the frozen pipes was not the real problem. The real problem
was that the pipes were freezing! Rather than ensure easy access to frozen pipes,
what was needed was a way to keep them from freezing in the first place. As
soon as this is seen to be the problem, the solution is straightforward: put the
pipes inside the heated walls.
Getting clear on the problem is a matter of defining it properly, and the skills
needed for this are the very same as those needed for constructing an adequate
definition of a key word.
ASSESS FOR TRUTH
We have seen that there are two questions we need to ask in assessing the reasons given in support of a decision, whether it is a decision about what to believe
or what to do. It is VERY important to keep these questions separate, since it is
one thing to agree with reasons but not with the conclusion and it is quite another to reject the reasons but accept the conclusion. Unless you are clear what you
are doing, no one else will be clear either.
1. Are they true?
What kind of claim is it? Specific, general, definition?
What is their source? Where did the evidence come from?
Experiment, measurement, memory, etc?
What are the conditions for trustworthiness of that source?
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Does this evidence meet those conditions?
2. Do those reasons really support the conclusion?
What kind of reasoning is being used:
Conditional, alternatives, analogies?
If it is not clear what kind of reasoning is at issue, can I reformulate
it in one of those forms?
Does the reasoning meet the conditions for being valid, or at least
logically strong?
Does it commit one of the fallacies?
How good is the analogy?
We can now add a third question:
3. Is the presentation thorough and comprehensive?
Were relevant alternative conclusions/decisions considered and
shown to be inferior?
Were reasons against the proposed decision stated and addressed?
EXPLORE THE VALUE
Any decision has to occur in a broader context. Understanding that context is
sometimes crucial for understanding the decision. If you are not sure what it is,
or if you do not make clear what it is, you will fail to properly evaluate or present a decision.
Some questions to keep in mind:
1. What is the issue the belief is about?
2. What problem is the decision being advanced to solve?
3. What is the history of attempts to solve that problem, and are there helpful lessons from past cases?
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1
John Dewey, How We Think, Boston, D.C Heath and Co., 1910. The reference is to its republication by
Dover in 1997, p. 29.
1
This case is described in Winning Decisions, by J. Edward Russo and Paul J.H. Shoemaker, Doubleday,
2002, pages 10-11. Their discussion draws on John Sculley’s autobiography, Odyssey, Harper & Row,
1987.
2
This case is described in Winning Decisions, by J. Edward Russo and Paul J.H. Shoemaker, Doubleday,
2002, pages 202-205. Their discussion is based on Siddhartha R. Dalal, Edward B. Fowlkes, and Bruce
Hoadly, “Risk Analysis of the Space Shuttle: Pre-Challenger Prediction of failure,”, Journal of the American Statistical Association, 84, no. 408 (December 1989): 945-57.
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