Critical Thinking Chapter 6

1. RECOGNIZING, ANALYZING,
AND CONSTRUCTING
ARGUMENTS
The aim of this tutorial is to help you learn to
recognize, analyze, and evaluate arguments.

2. How do politicians use logical arguments
and rhetoric in political debates?
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3. Arguments and issues
Arguments help us to analyze issues and to assess
whether positions on issues are reasonable or
unreasonable. An issue is an ill-defined complex of
problems involving a controversy or uncertainty.
Identifying an issue requires clear thinking as well as good
communication skills.
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4. Argument recognition
 Rhetoric is the art of persuasion—it is the defense of a
particular position usually without adequate
consideration of opposing evidence.
 Rhetoric can be useful once you have come to a
reasoned conclusion, and are now trying to convince
others of this conclusion.
 The goal of rhetoric is to “win.” The purpose of
argumentation, in contrast, is to discover the truth.
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5. Are the two people in this photo engaging
in rhetoric or argumentation?
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6. Hot or Not?
Is it acceptable to use rhetoric if
you’re sure of your position?
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7. Argument recognition (continued)
 Arguments are made up of two or more propositions,
one of which, the conclusion, is supported by the
other(s), the premise(s).
 There are two types of arguments
 Deductive arguments contain a conclusion that necessarily
follows from the premise.
 In inductive arguments, the premises provide support but not
necessarily proof for the conclusion.
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8. Propositions, conclusions, and
premises
 Propositions are statements that express a complete
thought. A proposition can either be true or false.
 The conclusion of an argument is the proposition that is
supported or denied on the basis of other propositions or
reasons. Also called claims, viewpoints, and positions, it
is what the argument is trying to prove. A conclusion can
appear anywhere in an argument.
 Premises are propositions that support or give reasons
for acceptance of the argument. Reasoning proceeds
from the premises to the conclusion.
 Good premises are based on fact and experience.
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9. Proposition:
“The Earth revolves around the sun.”
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10. Types of premises
 There are several types of premises.
 Descriptive premises are based on empirical facts:
scientific observation and/or sensory experience.
 Prescriptive premises, in contrast, contain value
statements.
 Analogical premises take the form of an analogy in which
a comparison is made between two similar events or
things.
 Definitional premises contain a definition of a key term for
purposes of precision or clarification.
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11. Nonarguments: explanations and
conditional statements
 Sometimes we confuse arguments with explanations
and conditional statements.
 An explanation is a statement about why or how
something is the case.
 A conditional statement is an “If…then…” statement
that offers no claim or conclusion.
 Unlike explanations and conditional statements, an
argument tries to prove that something is true.
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12. Conditional statement:
“If 18-year-olds are emotionally mature enough to go
to war, then they should be allowed to drink alcohol.”
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13. Breaking down arguments
 Knowing how to diagram and identify parts of an
argument allows us to visualize the entire argument, its
propositions, and its premise/conclusion relationship.
 Before you can diagram an argument, you must first
break it down into its propositions. First, bracket the
propositions; second, identify the conclusion; third,
identify the premises.
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14. Bracket the propositions:
“[Students who site in front of a classroom generally earn higher
grades.] Therefore, [you should move up to the front of the class],
since [I know you want to improve your grade point average].”
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15. Diagramming arguments using
symbols
 Diagramming arguments involves the use of specific
symbols to identify the different parts of an argument
and their relationships to each other.
 A circled number is used to indicate a proposition and where
it appears in the argument.
 A broken circle is used to indicate an unstated premise or
conclusion.
 An arrow is used to indicate the relationship between an
independent premise and the conclusion.
 A line is used to connect dependent premises.
 A line with an arrow below it is used to indicate the relationship
between dependent premises and the conclusion.
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16. Argument with dependent premises
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1 [The Bible states in Leviticus 20:26, “You should
not practice augury or witchcraft.”] Therefore,
[the Harry Potter books are not suitable reading for
children,] since [Harry Potter is a wizard] and
[wizards practice augury].
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1 3
2
4
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17. These people are burning Harry Potter books
based on their conclusion that Harry is a
wizard and witchcraft should not be practiced.
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18. Argument with an unstated conclusion
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1 Laws that permit public colleges to discriminate
against applicants on the basis of race or sex are
unconstitutional. The University of Michigan’s
affirmative action policy that awards extra points on
the basis of a person’s race and sex discriminates
against white males.
2
1 Laws that permit public colleges to discriminate
against applicants on the basis of race or sex are
unconstitutional. The University of Michigan’s
affirmative action policy that awards extra points on
the basis of a person’s race and sex discriminates
against white males. Therefore, the University of
Michigan’s affirmative action policy is unconstitutional.
2
3
1 2
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19. College students are divided regarding the
morality and constitutionality of affirmative action
in college admissions.
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20. Hot or Not?
Does knowing how to break down
and diagram arguments serve any
practical purpose in your life?
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21. Evaluating arguments
 Knowing how to break down and diagram arguments
makes it easier for you to evaluate them.
 Five criteria are useful for evaluating arguments:
 Clarity
 Credibility
 Relevance
 Completeness
 Soundness
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22. Evaluating clarity and credibility
 Clarity: Is the argument clear and unambiguous?
Clarifying another person’s argument requires good
listening skills and openness to ideas that may differ
from your own.
 Credibility: Are the premises supported by evidence?
Examine each premise carefully. Be alert for
assumptions that are passed off as facts.
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23. “Boys become doctors; girls become nurses”—
if one of the premises is false, the premises do
not support the conclusion.
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24. Evaluating relevance and
completeness
 Relevance: Are the premises relevant to the
conclusion? In addition to being true, the premises
should provide good reasons for accepting the
conclusion.
 Completeness: Are there any unstated premises and
conclusions? This is often the case within arguments
that are incompletely researched or loaded with
confirmation bias.
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25. Evaluating soundness
 Soundness: Are the premises true, and do they support
the conclusion? A sound argument is one in which the
premises are true and they support the conclusion.
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26. Constructing an argument
 Once you know how to identify, deconstruct, and
evaluate arguments, you are ready to construct your
own. The following eight steps are a useful guide to help
you improve the quality of your arguments.
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27. Eight steps to better arguments
 Begin by stating the issue. Try to use neutral language.
 Develop a list of premises. Remain as objective and
open-minded as possible.
 Eliminate weak or irrelevant premises.
 Establish a conclusion.
 Organize your argument. Clearly state your conclusion,
or thesis statement, in the opening paragraph.
 Test your argument using others.
 Revise your argument if necessary.
 If appropriate, act on your conclusion or solution.
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28. Working collaboratively to identify and
eliminate weak or biased premises can help
make your argument stronger.
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29. Hot or Not?
Does the two-party system in the
United States discourage the use
of logical argumentation in
resolving issues?
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30. Writing papers using logical arguments
 Writing effective college papers requires the use of good
structure, both in your argument and in the paper itself.
 Use the following approach as a guide:
 Identify the issue
 Present the premises
 Present and address counterarguments
 End the paper with an expanded version of your
conclusion. Restate the issue, and summarize your
argument thoroughly. Be sure to include references for all
facts and evidence used.
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31. Conclusions
Arguments are useful tools for making real-life decisions.
Skilled critical thinkers employ them to recognize conflict
and avoid or defuse it. They also avoid jumping to
premature conclusions, only taking a stand after studying
an issue from multiple perspectives.
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32. Was Lincoln’s decision to stand by his conclusion that slavery
should be illegal a wise one? Are there times when it is best to
back down on an argument rather than risk conflict?
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33. Perspectives on same-sex marriage
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