Think critically 3rd edtion facione gittens 2016 chapter 07

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Chapter 7
Evaluate Arguments: Four Basic
Tests

THINK CRITICALLY, FACIONE
& GITTENS

© 2016 by Pearson Education, Inc.


Learning Outcomes
• Explain the four presumptions about
argument making we make when we offer
one another reasons to support our claims
• Evaluate the worthiness of arguments by
applying the four tests: Truthfulness of the
Premises, Logical Strength, Relevance, and
Non-Circularity
• Recognize common reasoning mistakes
known as fallacies of relevance
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& GITTENS

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Chapter Opening Video

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& GITTENS

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Giving Reasons and Making
Arguments
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•
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Truthfulness
Logical strength
Relevance
Non-circularity

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Truthfulness
• People expect that the statements offered
when making arguments are true
– If a disagreement about the truth of any
statement should arise, people involved can:
• Make an effort to find out if that statement is true

• Qualify the force with which they assert and maintain
any claims in the line of reasoning that relies on the
statement

• Premise - Statement that is a component of
a reason
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Logical Strength
• The speaker’s reason is supposed to be
the logical basis for his or her claim
• The assumed truth of the premises of an
argument justifies or implies that the
conclusion also be taken as true

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Relevance
• Conclusion can be true independent of
whether the premises are true or logically
support the conclusion
– So What? presumption

• The listener takes the speaker’s reason to
be relevant in believing the speaker’s
claim

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Non-circularity
• Claim must not be part of the basis for
believing in the truth of the reason
• Argument making is directional

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Four Tests for Evaluating Arguments
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•
•
•
•

Test #1: Truthfulness of the premises

Test #2: Logical strength
Test #3: Relevance
Test #4: Non-circularity
Argument making contexts

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& GITTENS

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Test #1: Truthfulness of the
Premises
• Truth or falsity of premises is a priority in
critical thinking
• Person must get the information straight if
he or she does not have the best
information

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& GITTENS

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Test #2: Logical Strength
• An argument passes the test if there is no
possible scenario in which all the premises
can be true while its conclusion is false
– Sound argument: Contains true premises

and passes the Test of Logical Strength

• Multiple independent reasons can be
provided for a given claim

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& GITTENS

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Map 1

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Test #3: Relevance
• Test requires making a reasoned judgment
that the truth of the conclusion depends
upon the truth of the reason
• People with knowledge and experience
appropriate to context and issues under
discussion can easily apply the test

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Test #4: Non-circularity
• Requires that a claim is not relied upon a
chain of reasoning used to support its own
reason
• Argument flows in one direction, from
reasons and evidence toward the
conclusion

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Map 2

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Map 3

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Simulation

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Argument Making Contexts
• Desire for best knowledge is trumped by
the competitive need to vanquish the
opposition
– Argument making includes the search for facts
that support one’s preconceptions

• Winning an argument does not guarantee
that a best decision is made
• Vocabulary used to evaluate arguments
must be flexible
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Evaluative Adjectives for Arguments
and Their Elements

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Common Reasoning Errors
• Fallacies of relevance

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Fallacies of Relevance
• Appeals to ignorance
– It is false to assume that the absence of a
reason for an idea should count as a reason
against the idea

• Appeals to the mob
– One should not assume that because a large
group of people believe in something or do
something, their opinion is correct

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Fallacies of Relevance
• Appeals to emotion
– False to assume that one’s initial emotional
response to an idea, event, story, person,
image, or proposal is the best guide for
forming reflective fair-minded judgments

• Ad hominem attacks
– Claims that a person’s ideas must be tainted
because the person has some vice or flaw

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Fallacies of Relevance
• Straw man fallacy
• Assuming that, by refuting a weaker argument
among several independent reasons, one has
successfully refuted all the reasons for a claim
–Includes the practice of attributing to the
opposition an argument that is not theirs, and
then demolishing that argument

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Fallacies of Relevance
• Playing with words fallacy
– Exploits problematic vagueness, ambiguity,
donkey cart expressions, stereotyping, and
slanted language in order to support a claim

• Misuse of authority fallacy
– False assumption that if a powerful person
makes a claim, then the claim must be true

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