In which type of statement are the subject and predicate terms interchangeable?

A convertible statement is defined by its property that allows the subject and predicate terms to be interchanged while maintaining the truth of the statement. For instance, in the statement "All cats are animals," it can be converted to "All animals are cats," provided the initial statement is true. This interchangeability stems from the logical relationship expressed in the original statement; both terms imply a mutual connection that holds when switched.

In contrast, the other types of statements do not support such interchangeability. Particular affirmative statements involve some but not necessarily all members of the subject class, which means simply switching terms does not preserve truth. Universal negative statements assert a negation about all members of a class and would lose their intended meaning if the subject and predicate were exchanged. Enthymemes, which are logical arguments that omit one premise, do not focus on the relationship between the subject and predicate terms in this manner.

Therefore, the concept of convertibility uniquely applies to convertible statements, where a logical equivalence remains intact upon switching the subject and predicate.