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Chapter 16

Thinking and Speaking Critically

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Thinking and Speaking Critically

Critical Thinking• The process of making sound inferences

based on accurate evidence and valid reasoning

Pseudoreasoning• An argument that appears sound at first

glance but contains a fallacy of reasoning that renders it unsound

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Arguments

• Verbal aggressiveness attacking the self-concept of people

who disagree with you about controversial claims

• Argumentativeness arguing for and against the positions

taken on controversial claims constructive argumentativeness is the

best approach for the public speaker

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Toulmin’s Model of Reasoning

Grounds = evidence

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Toulmin’s Model of Reasoning

Claim = the point the arguer is trying to prove

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Toulmin’s Model of Reasoning

Warrant = links grounds and claim

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Toulmin’s Model of Reasoning

Backing = Support for the warrant

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Toulmin’s Model of Reasoning

Qualifier = Degree of certainty of the argument

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Toulmin’s Model of Reasoning

Rebuttal = Reasons that refute the argument

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Example using Toulmin Model

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What is a Fallacy?

An argument in which the reasons advanced for a claim fail to warrant acceptance of the claim

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Fallacies of Claims

• Red herring an irrelevant issue introduced into a

controversy to divert attention from the real controversy

• Arguing in a circle the use of a claim to prove its own

truth

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Fallacies of Grounds

• Unsupported assertion the absence of any argument at all

• Distorted evidence significant omission or change in the

grounds altering the original intent

• Isolated examples non-typical or non-representative example

• Misused statistics poor sampling, lack of significant differences,

misuse of average, misuse of percentages

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Fallacies of Warrants & Backing

• Authority warrant halo effect

• because you like or respect a person, you tend to believe whatever he or she says

ad hominem• attack against the person, not the

argument

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Fallacies of Warrants & Backing

• Generalization warrant hasty generalization

• uses specific instances to reach general conclusions

stereotyping• assumes that what is true of a larger class is

necessarily true of particular members of that class

false dilemma• implies there are only two choices

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Figure 15.3 Argument establishing a generalization

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Figure 15.4 Argument applying a generalization

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Fallacies of Warrants & Backing

• Comparison (analogy) warrant claims that two cases that are similar in

some known respects are also similar in some unknown respects

• Causal warrant post hoc, ergo propter hoc

• assumes that because one event preceded another, the first event must be the cause of the second event

slippery slope• assumes that just because one event occurs, it will

automatically lead to a series of undesirable events

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Fallacies of Warrants & Backing

• Sign warrant the presence of an observed

phenomenon is used to indicate the presence of an unobserved phenomenon

fallacy of mistaking correlation for cause: just because two things are related doesn’t mean one caused the other.

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Fallacies of Qualifiers

• Loaded language language that has strong emotional connotations

• Hyperbole an exaggeration of a claim

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Fallacies of Rebuttal

• Straw person refuting a claim by misstating the argument

being refuted

• Ignoring the issue failing to refute the claim being made by the

other side

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Non Sequitur

A non sequitur is an argument that does not follow from its premises