Introduction to Logic solution – name its mood and figure, and test its validity using a Venn diagram

EXAMPLE 1

1. Some reformers are fanatics, so some idealists are fanatics, because all reformers are idealists.

Some reformers are fanatics(P).

All reformers are idealists(S).

Some idealists are fanatics.

IAI-3

Valid.

 

EXAMPLE 2

2. Some philosophers are mathematicians; hence some scientists are philosophers, because all scientists are mathematicians.

Some philosophers(P) are mathematicians

All scientists(S) are mathematicians.

Some scientists are philosophers.

IAI-2

Invalid.

 

EXAMPLE 3

3. Some mammals are not horses, for no horses are centaurs, and all centaurs are mammals.

No horses(P) are centaurs.

All centaurs are mammals(S).

Some mammals are not horses

EAO-4

Invalid.

 

EXAMPLE 4

4. Some neurotics are not parasites, but all criminals are parasites; it follows that some neurotics are not criminals.

All criminals(P) are parasites.

Some neurotics(S) are not parasites.

Some neurotics are not criminals.

AOO-2

Valid.

 

EXAMPLE 5

5. All underwater craft are submarines; therefore no submarines are pleasure vessels, because no pleasure vessels are underwater craft.

No pleasure vessels(P) are underwater craft.

All underwater craft are submarines(S).

No submarines are pleasure vessels.

EAE-4

Invalid.

 

EXAMPLE 6

6. No criminals were pioneers, for all criminals are unsavory persons, and no pioneers were unsavory persons.

No pioneers(P) were unsavory persons.

All criminals(S) are unsavory persons.

No criminals were pioneers.

EAE-2

Valid.

 

EXAMPLE 7

7. No musicians are astronauts; all musicians are baseball fans; consequently, no astronauts are baseball fans.

All musicians are baseball fans(P).

No musicians are astronauts(S).

No astronauts are baseball fans.

AEE-3

Invalid.

 

EXAMPLE 8

8. Some Christians are not Methodists, for some Christians are not Protestants, and some Protestants are not Methodists.

Some Protestants are not Methodists(P).

Some Christians(S) are not Protestants

Some Christians are not Methodists.

OOO-1

Invalid.

 

EXAMPLE 9

9. No people whose primary interest is in winning elections are true liberals, and all active politicians are people whose primary interest is in winning elections, which entails that no true liberals are active politicians.

All active politicians(P) are people whose primary interest is in winning elections.

No people whose primary interest is in winning elections are true liberals(S).

No true liberals are active politicians.

AEE-4

Valid.

 

EXAMPLE 10

10. No weaklings are labor leaders, because no weaklings are true liberals, and all labor leaders are true liberals.

All labor leaders(P) are true liberals.

No weaklings(S) are true liberals.

No weaklings are labor leaders.

AEE-2

Invalid.

 

Related Posts

답글 남기기

이메일 주소는 공개되지 않습니다. 필수 필드는 *로 표시됩니다

이 사이트는 스팸을 줄이는 아키스밋을 사용합니다. 댓글이 어떻게 처리되는지 알아보십시오.