Critical thinking is clear thinking. It is the trained and practiced
exercise of talents that all human beings have, but that they do not always use.
Critical thinking examines the arguments by which we try to evaluate claims or
settle issues. This chapter initiates the study of critical thinking: its value,
its purpose, its subject matter.
2. Critical thinking is clear thinking about issues.
Clear thinking about an issue involves identifying the issue, recognizing
what positions people are taking on that issue, and understanding the arguments
for and against those positions.
All these steps can be quickly defined, but they cannot always be learned
The ultimate goal of the entire process is a decision: What are the
best reasons to accept a claim, reject it, or suspend judgment?
An issue is any point being discussed or thought about.
An issue may also be thought of as a question: Some assertion has to
be decided on.
Issues can usually be stated so that they begin with "whether":
Whether you should buy this car, or whether you should buy any car at all.
A psychological problem or hang-up is commonly called an "issue";
Nor is an issue something as broad as a topic of conversation, for a topic
does not always call for a question to be answered, and an issue does.
An argument is an attempt to support a claim by giving reasons for believing
The claim being argued for is the argument's conclusion, while the claim
or claims given as reasons for accepting the conclusion are premises.
Arguments are often confused with attempts to persuade.
It is true that good arguments can persuade people. But not all
arguments are made for the purpose of persuading, and without a doubt
not all attempts to persuade are arguments.
Talk about arguments and persuasion muddies the waters. Rather than
worrying about whether an argument can make someone else believe what
you say, focus on its purpose of proving or supporting a claim.
Another confusion comes when people think of arguments as explanations.
This confusion is more honest but can still lead you into trouble.
In later chapters the difference between arguments and explanations
should become clear.
Briefly, an argument tries to show that some sentence is true; an
explanation tries to say why something happens or how it happens.
To identify an argument you need to identify its conclusion and its
premises (or in some cases its single premise).
Very often certain words or phrases, conclusion indicators, point
to the coming conclusion: "therefore," "hence,"
"we may conclude," and so on.
Premise indicators likewise alert you to the appearance of a premise:
"since," "because," "given that," etc.
These indicators are only a first clue to the parts of an argument;
but though they are not always present, there are other techniques
for spotting the parts of arguments.
What complicates things even more is that an argument's conclusion
or one or more of its premises may never be stated explicitly.
4. The second step in thinking about an issue requires telling
the difference between factual and nonfactual issues or questions.
Factual issues are about factual claims. A factual claim does not have
to be true. But if it is true it states a fact.
"Beyond Pluto there is another planet" is a factual claim
even if we never find out the truth of it.
"'Eggplant' is a funnier word than 'broccoli'" is a nonfactual
Before discussing an issue you need to tell if it is a factual one.
One method: if two people disagree and at least one of them has to
be mistaken, the issue is factual. "Eggplant" may make you chuckle
while "broccoli" amuses me much more deeply, but neither of
us has to be wrong about anything.
Another method: If established methods exist for settling a question,
it is a factual question. Astronomers have definitions of planets and
know how to look for them; hence the question of a tenth planet is a factual
Even when methods exist for settling an issue, that issue might still
be controversial: "factual" does not mean "uncontroversial."
Sometimes this distinction leads to the belief that all opinions about
nonfactual issues are equally good.
Remember that an argument tries to support one position on a given
issue. One argument about a nonfactual matter may still be stronger or
weaker than another one, more or less relevant, grounded on firmer or
So even when the conversation turns to nonfactual issues it is vitally
important to produce and evaluate arguments with the same care you devote
to arguments about factual issues.
Questions of moral decisions and aesthetic judgments raise very important
types of nonfactual issues. In discussions of those issues it is especially
important to insist on good arguments. See Chapter 13 for more.
Sometimes however people ignore the distinction between factual and nonfactual
issues, with grave and undesirable consequences.
Subjectivism is the view that two people can disagree about a factual
issue and both of them still be "right."
Relativism, a subjectivism about different cultures, claims that two
cultures can disagree about a factual issue while, again, both of them
Both of these doctrines are at best confused about what "right"
means and what a factual issue is. Critical thinking is thinking that
avoids falling into the pothole of subjectivism.
5. As a final preparation to clear thinking, watch out for
the factors that might influence your decision about a claim but are in fact
irrelevant to that decision.
Human beings are commonly influenced by considerations that strictly speaking
do not have to do with the truth of a claim
We take friends' and relatives' opinions more seriously than those
of strangers; we feel more like agreeing with people who present themselves
attractively or speak well.
Likewise, a clumsy and shy delivery can make us reject what a speaker
Some words are more persuasive than others: two sentences may convey
exactly the same claim, one of them in neutral terms and the other in
Being influenced in these and similar ways is natural but needs to be watched
The purpose of critical thinking is not to bleach all the emotion out
of you; nor to make you ignore your family members' opinions. ("I'm
not going to pay any special attention to what you say, Grandpa, to me
you are just one more person.")
From the specific point of view of assessing arguments, however, such
considerations need to be separated from considerations of the merits
of arguments themselves.
Compare critical thinking to auto mechanics. A mechanic at work on
a car ignores the color, shape, and design of the car, not out of insensitivity
but because those features do not bear on how well the car runs or what
might be wrong with it. Many mechanics are car lovers; as human beings
they are fascinated by the looks of a car. As mechanics however they keep
those irrelevant features separated from what they are doing. Likewise:
As an emotional person you might find yourself very strongly moved by
the language of a statement, or the circumstances of who made a certain
claim; but as a critical thinker you set those matters aside and focus
on what is relevant to the statement's truth.