« on: November 29, 2007, 10:16:20 PM »
MB ---> D
D ---> I
Therefore, MB ---> I; S ---> Not MB
S--->not MB is unsupported, so we need a premise that supports it.
Answer choice D says "the spirit is perfect" which is the same as saying the spirit is not imperfect.
If we take the contrapositive of MB ---> I, we get not I---> not MB. If we combine this with D we get:
S--->not I--->not MB
Which yields S--->not MB, which is the unsupported part of the conclusion.