RAS question
Statements: No cat is a dog. All dogs are faithful. Conclusions: I. No cat is faithful. II. Some faithful beings are not cats. Which conclusion(s) follow?
Correct answer: (A) Only Conclusion II follows.
Only Conclusion II follows: some faithful beings are not cats.
Explanation
The two statements must be linked through the middle term, dogs. Since all dogs are faithful, the syllogism rule treating an all-statement as yielding a some-statement lets us infer that some faithful beings are dogs. The first statement says no cat is a dog, so those faithful beings that are dogs cannot be cats. That gives the definite conclusion, some faithful beings are not cats. Conclusion I goes further than the premises allow: the statements exclude cats from the class of dogs, but they do not exclude cats from the wider class of faithful beings. A cat could still be faithful without being a dog, so no cat is faithful is not forced by the premises.
Why the other options are wrong
- (B) Conclusion I does not follow because the premises say cats are not dogs, not that cats are outside the whole class of faithful beings.
- (C) Both conclusions cannot follow because Conclusion II is forced through faithful dogs, while Conclusion I wrongly denies every possible faithful cat.
- (D) Neither is too strong a rejection because Conclusion II is a valid particular negative conclusion from faithful dogs being non-cats.
Concept
This tests syllogism, especially distribution, conversion, and the move from universal premises to definite particular conclusions. It recurs in RAS reasoning because small changes between all, no and some often decide whether a conclusion is logically forced.