Introduction / Context:
This is a classic syllogism problem. From a universal affirmative premise (“All soldiers serve their country”), we must infer the statement that must be true without adding extra information.
Given Data / Assumptions:
- Premise: For every x, if x is a soldier, then x serves their country.
- Implicit existence: The category “soldiers” is non-empty in ordinary-language reasoning unless stated otherwise.
Concept / Approach:
- Universal affirmative (All S are P) logically licenses the particular affirmative (Some S are P) under standard existential reading.
- The converse (All P are S) and only-if forms (“only soldiers serve”) do not follow.
Step-by-Step Solution:
From “All soldiers serve,” it necessarily follows that at least one member of the set “soldiers” (if any exist) serves—the particular case “Some soldiers serve.”Statements converting or restricting the predicate class (options a, b, d) add content not justified by the premise.
Verification / Alternative check:
Test counterexamples: It can be true that many non-soldiers also serve (invalidates b and d), and that some who serve are not soldiers (invalidates a). But nothing contradicts “Some soldiers serve.”
Why Other Options Are Wrong:
a: Converse error. b,d: Illicit restriction of the predicate set. e: Not needed because one option is correct.
Common Pitfalls:
Assuming “all S are P” implies “all P are S” (it does not).
Final Answer:
Some soldiers serve their country.
Discussion & Comments