6 of the valid and invalid argument forms (TEST #2)
Syllogism
A instance of a form of reasoning in which a conclusion is drawn (whether validly or not) from two given or assumed premises, each of which shares a term with the conclusion, and shares a common or middle term not present in the conclusion EX: Major premise: All men are mortal. Minor premise: Socrates is a man. Conclusion: Socrates is mortal.
Dilemma
The valid argument form If P then Q; If Not-P then Q; therefore, Q.
Modus Tollens
The valid argument form If P then Q; Not-Q; therefore, Not-P. _______________________________ The rule of logic stating that if a conditional statement ("if p then q ") is accepted, and the consequent does not hold ( not-q ), then the negation of the antecedent ( not-p ) can be inferred.
Modus Ponens
The valid argument form If P then Q; P; therefore, Q. _______________________________ The rule of logic stating that if a conditional statement ("if p then q ") is accepted, and the antecedent ( p ) holds, then the consequent ( q ) may be inferred.
Denying the Antecedent
the invalid argument form If P then Q; Not-P; therefore, Not-Q. ------------------------ Is a formal fallacy of inferring the inverse from the original statement.
Affirming the Consequent
the invalid argument form If P then Q; Q; therefore, P. ------------------------ Is the action of taking a true statement and invalidly concluding its converse
Disjunctive syllogism
these two valid argument forms: P or Q; Not-P; therefore Q P or Q; Not-Q; therefore P ------------------------ It is a valid argument form which is a syllogism having a disjunctive statement for one of its premises.