Some dark haired pixies are elves that play tricks. Therefore, some elves that do not play tricks are light haired pixies.
A) Invalid, illicit conversion.
B) Invalid, illicit contraposition.
C) Invalid, existential fallacy.
D) Invalid, illicit subcontrary.
E) Valid, no fallacy.

Question

Quizplus · Accepted Answer

The original statement does not logically imply its converse or its contrapositive. The error in reasoning here is assuming that the contrapositive of the original statement is true, which is an illicit contraposition. The original statement about some dark haired pixies being elves that play tricks does not logically lead to any conclusions about elves that do not play tricks or their hair color.

Some Dark Haired Pixies Are Elves That Play Tricks