M A The case of men appreciating the law of retribution, is the case ―――――――――――――――――――――――――――――――――――――――――― G of men doing right for the sake of themselves; S M E But men do not appreciate the law of retribution, ――― ――――――――――――――――――――――――――――――――― S G E ∴ Men do not do right for the sake of themselves. ――― ―――――――――――――――――――――――――――――――― Fallacy of illicit major. (6) “If an animal is a vertebrate, then it must have a backbone; but the books say that this animal is not a vertebrate, hence it cannot have a backbone.” Since the minor premise denies the antecedent it would appear that the argument is invalid; yet common knowledge and common sense dictate that the conclusion is true. Surely no invertebrate can have a backbone. As a matter of fact the antecedent and consequent are _co-extensive_ and therefore the hypothetical rule is not applicable. _Reduced to the categorical_: M G A Vertebrates must have a backbone (Co-extensive), ――――――――――― ―――――――――― S M E This animal is not a vertebrate, ―――――― ―――――――――― E ∴ This animal cannot have a backbone. ―――――― ―――――――――― As co-extensive A’s distribute their predicates the possibility of there being a fallacy of illicit major is forestalled. Categorically considered the argument is likewise valid. =8. DISJUNCTIVE ARGUMENTS.= It has been observed that a disjunctive proposition is one which expresses an alternative. _A disjunctive syllogism is one in which the major premise is a disjunctive proposition._ ILLUSTRATION: The boy is either honest or dishonest, He is honest, ∴ He is not dishonest. =9. THE TWO KINDS OF DISJUNCTIVE ARGUMENTS.= The two forms of disjunctive arguments are _the one which by affirming denies_ and _the one which by denying affirms_. The former is known by the Latin words “_modus ponendo tollens_”; while the latter is termed the “_modus tollendo ponens_.” ILLUSTRATIONS: (1) By affirming denies. The defendant is either guilty or innocent, He is guilty, ∴ He is not innocent. or The defendant is either guilty or innocent, He is innocent, ∴ He is not guilty. (2) By denying affirms. The defendant is either guilty or innocent, He is not guilty, ∴ He is innocent. or The defendant is either guilty or innocent, He is not innocent, ∴ He is guilty. =10. THE FIRST RULE OF DISJUNCTIVE ARGUMENTS.=