Ch 3
Truth-Preserving
A characteristic of a valid deductive argument in which the logical structure guarantees the truth of the conclusion if the premises are true
Syllogism
A deductive argument made up of three statements - two premises and a conclusion (modus ponens and modus tollens)
Invalid Argument
A deductive argument that fails to provide conclusive support for its conclusion
Valid Argument
A deductive argument that succeeds in providing conclusive support for its conclusion
Sound Argument
A deductively valid argument that has true premises
Dependent Premise
A premise that depends on at least one other premise to provide joint support to a conclusion; if a dependent premise is removed, the support that its linked dependent premises supply to the conclusion is undermined or completely canceled out
Independent Premise
A premise that does not depend on other premises to provide support to a conclusion; if an independent premise is removed, the support that other premises supply to the conclusion is not affected
Cogent Argument
A strong inductive argument with all true premises
Hypothetical Syllogism
A valid argument form made up of three hypothetical, or conditional, statements: If p, then q. If q, then r. Therefore, if p, then r.
Disjunctive Syllogism
A valid argument form: Either p or q. Not p. Therefore, q. (In the syllogism's second premise, either disjunct can be denied.)
Denying the Consequent (Modus Tollens)
A valid argument form: If p, then q. Not q. Therefore, not p.
Affirming the Antecedent (Modus Ponens)
A valid argument form: If p, then q. p. Therefore, q.
Modus Ponens
Affirming the antecedent -- a valid argument form: If p, then q. p. Therefore, q.
Conditional Statement
An "if-then" statement; it consists of the antecedent (the part introduced by the word if) and the consequent (the part introduced by the word then)
Inductive Argument
An argument in which the premises are intended to provide probable, not conclusive, support for its conclusion -- described as strong or weak
Deductive Argument
An argument intended to provide logically conclusive support for its conclusion -- described as valid or invalid
Weak Argument
An inductive argument that fails to provide strong support for its conclusion
Strong Argument
An inductive argument that succeeds in providing probable - but not conclusive - support for its conclusion
Denying the Antecedent
An invalid argument form: If p, then q. Not p. Therefore, not q.
Affirming the Consequent
An invalid argument form: If p, then q. q. Therefore, p.
Antecedent
The first part of a conditional statement (If p, then q.), the component that begins with the word if.
Consequent
The part of a conditional statement (If p, then q.) introduced by the word then
Modus Tollens
Denying the consequent -- a valid argument form: If p, then q. Not q. Therefore, not p.