In a previous question there was a debate as to whether Voldemort is a genius or not. Here is some evidence towards his magical intelligence:
Possessed a power beyond almost any wizard in known history, and since magic has a lot to do with knowledge, he must have had greater magical knowledge than any wizard in known history.
Left Hogwarts with "top grades in every examination he had taken".
Is very loquacious: He inspires fear and loyalty in his followers. Also leaders in general need to be smart in order to make intelligent decisions. (Not sure if speaking Parseltongue makes you loquacious...)
Obviously he possessed knowledge regarding magic that far surpassed almost anyone in the Harry Potter universe. However if we discount his magical knowledge, does he possess an extraordinary intelligence that isn't a result of his lust for magical knowledge? There is certainly evidence of poor decisions made by him, are there examples outside of magical knowledge that show he possesses superior intelligence?