Categorical Syllogism Exercise

1. Categorical Syllogism Exercise

2. Identify major, minor, and middle terms, mood, and figure All ozone molecules are good absorbers of UV light. All ozone molecules are things destroyed by chlorine. Therefore, some things destroyed by chlorine are good absorbers of UV light.

3. Major term: good absorbers of UV light Minor term: things destroyed by chlorine Middle term: ozone molecule Mood-figure: AAI-3; invalid under Boolean standpoint, valid under Aristotelian one.

4. Construct a syllogism An EIO-2 syllogism with these terms: major: fans of Twins; minor: lovers of good music; middle: persons capable of independent thinking.

5. No fans of Twins are persons capable of independent thinking. Some lovers of good music are persons capable of independent thinking. Some lovers of good music are not fans of Twins.

6. Use Venn diagrams to determine validity No AIDS victims are persons who pose an immediate threat to the lives of others. Some kindergarten children are AIDS victims. Therefore, some kindergarten children are not persons who pose an immediate threat to the lives of others.

7. No concertos are symphonies. No symphonies are string quartets. Therefore, no string quartets are concertos.

8. Use Venn diagrams to see whether a valid conclusion can be drawn from premises Some P are not M. All M are S.

9. Some P are not M. All S are M.

10. All P are M. All S are M.

11. Reduce the number of terms and use Venn diagram to test validity No cases of AIDS are infections easily curable by drugs, since all diseases that infect the brain are infections not easily curable by drugs, and all diseases that do not infect the brain are cases other than AIDS.

12. All D are non-I. (obversion) No D are I. All non-D are non-C. (contraposition) All C are D. No C are I. No C are I. Valid

13. Translate into standard form and use Venn diagram to test validity Wherever icebergs are present, threats to shipping exist. Icebergs are not present in the South Pacific. Hence, there are no threats to shipping in the South Pacific.

14. Supply the missing proposition in the enthymeme and convert it into a valid argument Any drastic decline in animal life is cause for alarm, and the current decline in frogs and toads is drastic.

15. All of the operas except Mozart�s were well performed, and Carmen was not written by Mozart.

16. Wherever water exists, human life can be sustained, and water exists on the moon.

17. Convert the enthymemes into the standard forms of valid syllogisms Committing suicide is a right. If a person decides that life is impossible, it is his or her right to end it.

18. Encouraging toy-gun play gives children a clear message that the best way to deal with frustration and conflict is with a gun. Is this the message we want to be sending our kids?

19. Rewrite the sorites in standard form, supply the intermediate conclusions and test for validity No S are M. All F are S. Some M are H. All E are F. Some H are not E.

20. All M are non-P. Some M are S. All K are P. Some non-K are not non-S.

21. Rewrite the sorites in standard form, use Venn diagram to prove validity Some college students purchase their term papers. Any cheat is expelled from college. No one will achieve his career goals if he/she is expelled. No one who purchase term papers is other than a cheat. Therefore, some college students will not achieve their career goals.

22. Creation science does not favor the teaching of evolution. Nothing should be taught that frustrates the understanding of life. Whatever opposes the teaching of evolution impedes the learning of biology. Anything that enhances the understanding of life fosters the learning of biology. Therefore, creation science should not be taught.

23. All writers who understand human nature are clever. No one is a true poet unless he can stir the hearts of men. Shakespeare wrote Hamlet. No writer who does not understand human nature can stir the hearts of men. None but a true poet could have written Hamlet. Shakespeare was clever.