Is the syllogism 'No S are M; All P are M; Therefore No S are P' valid? (Figure II)

• A. Yes (valid Figure II form)
• B. No
• C. Yes (invalid)
• D. Only with universal major premise

Answer: (A)

Think of how the middle term links the other two. The first premise says S and M do not overlap. The second premise says every P lies inside M. If all P are inside M, and S cannot overlap M at all, then S cannot overlap P either. In other words, nothing that is S can be P, so No S are P follows.

This fits the figure II pattern, where the middle term makes the bridge between the two endpoints. Here M is the region that contains P and is separate from S, so the conclusion that S and P do not overlap is guaranteed. Hence the syllogism is valid.