Ch 3
Cogent Argument
A strong inductive argument with all true premises
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.
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)
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
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
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.
Affirming the Antecedent (Modus Ponens)
A valid argument form: If p, then q. p. Therefore, q.
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.
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
Inductive Argument
An argument in which the premises are intended to provide probable, not conclusive, support for its conclusion -- described as strong or weak
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.
Sound Argument
A deductively valid argument that has true premises