A E (7) Test the validity of E in the third figure; of I in the third. E O (8) Independent of all helps, prove the truth of the canons of the first figure. (9) In a similar way prove the canons of the second, third and fourth figures. (10) So far as testing arguments is concerned, what use may be made of the special canons of the syllogism? (11) Offer a few suggestions for remembering the special canons. (12) Why did Aristotle attach so much importance to reduction in logic? (13) Justify calling the first figure the “perfect figure,” and the others the “imperfect figures.” (14) Treat of the relative value of the four figures. (15) Show by illustration that the second figure is the exclusive figure. E O I (16) Test the following moods in all the figures: I A A A O I A E E A A E A A A E I A E I E O A I. O O O O E I I I I =12. QUESTIONS FOR ORIGINAL THOUGHT AND INVESTIGATION.= (1) Give an illustration of a syllogism in the fourth figure which might just as well be written in the first figure. (2) May a syllogism, which is invalid in the fourth figure, be made valid by writing it in the form of the first figure? Prove it. (3) Show why it is impossible to apply all the rules of the *** (4) Show the difference between a direct and an indirect proof. A (5) Show that A is valid in the first figure when the major premise O (A) is co-extensive. (6) The third figure is known as the figure of particular conclusions. Why should not the second canon of that figure be, “_One premise_ must be particular” rather than “The conclusion must be particular?” (7) Show that there is some ground for thinking that, as a final test, moods in the other figures should be reduced to the first. (8) Illustrate the fact that the second figure is the figure of disproof; whereas the third is the figure of contradictions. (9) “To be logical a syllogism must conform to one of the four figures, but this does not mean, necessarily, that _all arguments_ must conform to some figure.” Explain this. CHAPTER 13. INCOMPLETE SYLLOGISMS AND IRREGULAR ARGUMENTS. =1. ENTHYMEME.= _An enthymeme is a syllogism in which one of the three propositions is omitted._ Suppressing the major premise gives an enthymeme of the _first order_; whereas if the minor premise be suppressed, the enthymeme becomes one of the _second order_; while omitting the conclusions gives an enthymeme of the _third order_. _Illustrations_: