Categorical syllogism basic rules – UGC NET Question

Statements A, B and C express standard rules from traditional syllogistic logic. A is correct because a categorical syllogism uses three and only three terms, each appearing in specific roles. B is correct since failure to distribute the middle term at least once leads to the fallacy of undistributed middle. C is also true because with two negative premises there is no logical basis to relate the subject and predicate terms, so no conclusion follows. Statement D is false because valid syllogisms cannot have both premises negative and the conclusion negative simultaneously, so only A, B and C form the correct set.

Option A:
Option A is incomplete as it includes only A and B but omits C, which is an important rule prohibiting valid conclusions from two negative premises. Without C, the characterisation of valid and invalid syllogisms is not complete. This makes the option unsuitable for the correct answer.

Option B:
Option B is correct because it brings together all the true statements about term count, middle-term distribution and the restriction on negative premises. It also implicitly excludes the incorrect idea in D that a valid syllogism may have all three statements negative. This matches the logical rules examined in NET questions.

Option C:
Option C is incorrect because it includes D, which falsely allows a configuration with both negative premises and a negative conclusion, while omitting B. Losing the distribution condition on the middle term and accepting a wrong rule about negativity makes the option invalid.

Option D:
Option D is wrong because it pairs B with D, treating the clearly false D as if it were correct and leaving out A and C. The combination therefore mixes truth with error and fails to capture the overall structure of valid categorical syllogisms.