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