VALID FORMS | INVALID FORMS |
---|---|
Direct Reasoning A ![]() A ![]() One premise is an if...then statement, the other premise affirms the antecedent, and the conclusion affirms the consequent. | Fallacy of the Converse A ![]() B ![]() One premise is an if...then statement, the other premise affirms the consequent, and the conclusion affirms the antecedent. |
Contrapositive Reasoning A ![]() ~B ![]() One premise is an if...then statement, the other premise denies the consequent, and the conclusion denies the antecedent. | Fallacy of the Inverse A ![]() ~A ![]() One premise is an if...then statement, the other premise denies the antecedent, and the conclusion denies the consequent. |
Transitive Reasoning A ![]() B ![]() ![]() ![]() One premise is an if...then statement, another premise is an if...then statement whose antecedent matches the consequent of the other premise, and the conclusion results from this chain of reasoning. | False Chains A ![]() A ![]() ![]() ![]() A ![]() C ![]() ![]() ![]() An incorrect attempt at Transitive Reasoning, in which two if...then premises agree in the antecedent, or agree in the consequent. |
Disjunctive Syllogisms A ![]() ~B ![]() A ![]() ~A ![]() One premise is an "or" statement, the other premise denies part of the "or" statement, and the conclusion affirms the other part. | Disjunctive Fallacies A ![]() B ![]() A ![]() A ![]() One premise is an "or" statement, the other premise affirms part of the "or" statement, and the conclusion may affirm or deny the other part. |