Deductive Logic Part 57

(1) No miser is a true friend, for he does not a.s.sist his friend with his purse.

(2) Governments are good which promote prosperity.

The government of Burmah does not promote prosperity.

.'. It is not a good government.

(3) Land is not property.

Land produces barley.

.'. Beer is intoxicating.

(4) Nothing is property but that which is the product of man's hand.

The horse is not the product of man's hand.

.'. The horse is not property.

(5) Some Europeans at least are not Aryans, because the Finns are not.

(6) Saturn is visible from the earth, and the moon is visible from the earth. Therefore the moon is visible from Saturn.

(7) Some men of self-command are poor, and therefore some n.o.ble characters are poor.

(8) Sparing the rod spoils the child: so John will turn out very good, for his mother beats him every day.

(9) Some effects of labour are not painful, since every virtue is an effect of labour.

(10) The courageous are confident and the experienced are confident. Therefore the experienced are courageous.

(11) No tale-bearer is to be trusted, and therefore no great talker is to be trusted, for all tale-bearers are great talkers.

(12) Socrates was wise, and wise men alone are happy: therefore Socrates was happy.

II.

1. From the major 'No matter thinks' draw, by supplying the minor, the following conclusions--

(1) Some part of man does not think.

(2) The soul of man is not matter.

(3) Some part of man is not matter.

(4) Some substance does not think.

Name the figured mood into which each syllogism falls.

2. Construct syllogisms in the following moods and figures, stating whether they are valid or invalid, and giving your reasons in each case--

AEE in the first figure; EAO in the second; IAI in the third; AII in the fourth.

3. Prove that 'Bra.s.s is not a metal,' using as your middle term 'compound body.'

4. Construct syllogisms to prove or disprove--

(1) Some taxes are necessary.

(2) No men are free.

(3) Laws are salutary.

5. Prove by a syllogism in Bokardo that 'Some Socialists are not unselfish,' and reduce your syllogism directly and indirectly.

6. Prove the following propositions in the second figure, and reduce the syllogisms you use to the first--

(1) All negroes are not averse to education.

(2) Only murderers should be hanged.

7. Prove in Baroko and also in Ferio that 'Some Irishmen are not Celts.'

8. Construct in words the same syllogism in all the four figures.

9. Invent instances to show that false premisses may give true conclusions.

III.

1. What moods are peculiar to the first, second, and third figures respectively?

2. What moods are common to all the figures?

3. Why can there be no subaltern moods in the third figure?

4. What is the only kind of conclusion that can be drawn in all the figures?

5. Show that IEO violates the special rules of all the figures.

6. In what figures is AEE valid?

7. Show that AEO is superfluous in any figure.

8. Prove that O cannot be a premiss in the first figure, nor a minor premiss anywhere but in the second.

9. Show that in the first figure the conclusion must have the quality of the major premiss and the quant.i.ty of the minor.

10. Why do the premisses EA yield a universal conclusion in the first two figures and only a particular one in the last two?

11. Show that AAI is the only mood in the fourth figure in which it is possible for the major term to be distributed in the premiss and undistributed in the conclusion.

12. Why are the premisses of Fesapo and Fresison not transposed in reduction like those of the other moods of the fourth figure?