It is false that no blue jays are pesky creatures. Therefore, all blue jays are pesky creatures.
A) Valid; no fallacy.
B) Invalid; illicit subcontrary.
C) Invalid; illicit contrary.
D) Invalid; existential fallacy.
E) Valid; illicit subalternation.

Question

Quizplus · Accepted Answer

The statement commits the fallacy of illicit contrary. The original statement "It is false that no blue jays are pesky creatures" can be restated as "Some blue jays are pesky creatures." However, it does not logically follow that all blue jays are pesky creatures. The correct logical statement would be "Some blue jays are pesky creatures" and "Some blue jays are not pesky creatures."

It Is False That No Blue Jays Are Pesky Creatures