1. Evaluate Deductive Reasoning and Spot Deductive Fallacies
Chapter 8
Evaluate Deductive Reasoning and Spot Deductive Fallacies

2. Deductive Validity and Language
An argument is deductively valid if there is no possibility, real or imaginable:
Short of changing the very meanings of the terms and the rules of grammar:
That will make the premises all true and the conclusion false
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3. Deductive Validity and Language
Certain configurations of language form deductively valid argument templates
Without violating the meanings of the words/grammatical rules of the language:
There is no possible way for the premises all to be true and the conclusion false
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4. Deductive Validity and Language
Reasoning Deductively about Declarative Statements
Denying the Consequent
Affirming the Antecedent
Disjunctive Syllogism
Neither, Unless, and Only
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5. Deductive Validity and Language
Reasoning Deductively about Classes of Objects
Applying a Generalization
Applying an Exception
The Power of Only
One of the most interesting words in the language:
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6. Deductive Validity and Language
Only has the power to change the meaning of a sentence depending on where it is placed
Classes and Objects
Reasoning Deductively about Relationships
Natural languages are rich with terms that describe relationships
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7. Deductive Validity and Language
Our understanding of the logical implications of relational terms is part of:
Our comprehension of language
Transitivity, Reflexivity, and Identity
Transitivity Relationship
Reflexivity Relationship
Identity Relationship
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8. Grammatically Equivalent Structures
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11. Fallacies Masquerading as Valid Deductive Arguments
Just as there are valid argument templates there are fallacious argument templates
Precision of thought and expression is the key to avoiding these mistakes in:
Our own argument making and also in our evaluation of the arguments offered to us
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12. Fallacies Masquerading as Valid Deductive Arguments
Fallacies When Reasoning with Declarative Statements
Affirming the Consequent
Denying the Antecedent
The House M.D. Fallacy
Fallacies When Reasoning about Classes of Objects
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13. Fallacies Masquerading as Valid Deductive Arguments
There are logically correct ways of reasoning about classes of objects & their members:
There are familiar mistakes we often hear being made
False Classification
Examples of False Classification seem remarkably abundant
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14. Fallacies Masquerading as Valid Deductive Arguments
Fallacies of Composition and Division
Reasoning about the relationships of parts and wholes can appear to be deductively valid:
But fail because the attribute that applies to the parts may not apply to the whole, or vice versa
Mistaken Identity
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15. Fallacies Masquerading as Valid Deductive Arguments
Fallacies that occur when reasoning about relationships like identity, reflexivity, or transitivity:
Most often occur when people think they are talking about the same thing, but in fact are not
False Reference
Create Your Own Deductive Reasoning Examples
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