(13) Define and illustrate a disjunctive argument.
(14) Exemplify the two kinds of disjunctive arguments.
(15) What is meant by a logical disjunction?
(16) “The alternatives must be mutually exclusive.” Explain this, illustrating fully.
(17) Cite cases where the enumeration is not complete.
(18) State in complete form both of the rules to which all disjunctive arguments must conform.
(19) Show by illustration how the disjunctive syllogism may be reduced to the categorical.
(21) Give examples, using symbols, of the four dilemmatic forms. Explain why these forms are so named.
(22) Why does the hypothetical rule apply to the dilemmatic syllogism?
(23) Test the validity of the following: Give reasons.
(1) “If a substance is solid it possesses elasticity and so also it does if it be a liquid or gaseous; but all substances are either solid, liquid or gaseous; therefore, all substances possess elasticity.” (2) “If men were prudent, they would act morally for their own good; if benevolent, for the good of others. But many men will not act morally, either for their own good or that of others; such men, therefore, are not prudent or benevolent.” (3) “If the majority of those who use public houses are prepared to close them, legislation is unnecessary; but if they are not prepared for such a measure, then to force it upon them by outside pressure is both dangerous and unjust.” (4) “The man is either a liar or a fool and in either case he is beneath my attention.” (5) “Either he is sincere or else he is the most astute impostor the world has ever produced; for me I prefer to think him sincere.”
(24) Explain the relation that many experiences appear to bear toward an argument introduced by a disjunctive proposition and followed by a hypothetical syllogism. Illustrate.
=21. QUESTIONS FOR ORIGINAL THOUGHT AND INVESTIGATION.=
(1) May both premises of a hypothetical argument be hypothetical propositions? Explain. See Fowler p. 115.
(1) If A is B, C is D If A is B, E is F ∴ If C is D, E is F
(2) If A is B, C is D If C is D, E is F ∴ If A is B, E is F
(3) Show by circles that two of the possible four hypothetical arguments are invalid.
(4) What categorical rules does the hypothetical argument seem to violate? Explain.