Which figure is associated with the Barbara mood AAA-1?

• A. Figure II
• B. Figure I
• C. Figure III
• D. Figure IV

Answer: (B)

The key idea here is how a syllogism’s figure is determined by the position of the middle term in the two premises. For Barbara in the mood AAA-1, the middle term serves as the subject of the major premise and as the predicate of the minor premise, which is the defining arrangement of Figure I.

In this figure, the standard form reads: Major premise All M are P; Minor premise All S are M; Therefore All S are P. The middle term M links S and P across the two premises, so from All S are M and All M are P we can conclude All S are P. This combination of universal premises and the specific placement of M is what makes Barbara-1 fit Figure I. If the middle term were placed differently, in another figure, the same mood wouldn’t yield the same valid form.