I have received several inquiries regarding other possible solutions to the syllogism translations in Introductory Logic Exercise 27. Though the Teacher’s Edition offers only one solution per problem, there are in fact many possible correct answers to each question.
Here is one more reasonable possibility for each:
- No Christians are unbelievers.
Some Christians are Calvinists.
Therefore, some Calvinists are not unbelievers.
- All murmuring is nonsense.
All mumbling is murmuring.
Therefore, all mumbling is nonsense.
- No humans are immortals.
All perfect beings are immortals.
Therefore, no perfect beings are humans.
- All good logicians are less-than-six-foot-tall people.
All eighth-graders are good logicians.
Therefore, all eighth-graders are less-than-six-foot-tall people.
- No mature people are impatient people.
Some mature people are not adults.
Therefore, some adults are not impatient people. (invalid)
- No gold things are inexpensive things.
All things that glitter are gold things.
Therefore, no things that glitter are inexpensive things.
Of course, there are even more possible correct answers, but I hope that this helps you move forward.