Difficulty: Easy
Correct Answer: Both I and II follow
Explanation:
Introduction / Context:
This problem tests basic categorical syllogism with two premises and conclusions that must follow necessarily in all valid interpretations. The terms are Authors, Learned people, and Doctors. We must avoid real-world knowledge and rely only on logical structure.
Given Data / Assumptions:
Concept / Approach:
Use set/venn reasoning. From a universal premise (All A are L) and a particular premise (Some D are A), we can push membership through the subset relation.
Step-by-Step Solution:
Step 1: From Premise 2, choose an element x that is Doctor and Author.Step 2: Apply Premise 1 to x. Since all Authors are Learned, x is Learned.Step 3: Therefore x is both Doctor and Learned, proving “Some Doctors are Learned.” (Conclusion I)Step 4: The same witness x also proves “Some Learned are Doctors.” (Conclusion II)
Verification / Alternative check:
A standard Venn diagram with Authors inside Learned and an overlapping Doctors region intersecting Authors immediately shows a non-empty overlap between Doctors and Learned.
Why Other Options Are Wrong:
Common Pitfalls:
Confusing “some” with “all,” or thinking that the converse of a universal requires a separate proof. Here, the particular premise supplies existence, and the universal moves that element into Learned.
Final Answer:
Both I and II follow.
Discussion & Comments