At the risk of being pedantic (and without going back to check the primary souces cited inte the quote-books):

Barlett's (13th ed.): "Those whom God wishes to destroy, he first deprives of their senses." Euripedes [keiva's note: a mis-translation? "God" rather than "the gods"?]
Footnote to the above states that in Boswell's Life of Dr. Johnson (1971), "this is quoted as a saying which everybody repeats, but nobody knows where to find." Also provides quotes similar quotes from Publilius Syrus, Lycurgus, Dryden, and Longfellow.

Evans' Dictionary of Quotations: "Whom Zeus would destoy, he first makes mad. [Sophocles: Antigone (c. 450 B.C.)] The statement, which may well have been proverbial when Sophocles used it, has passed though its Latin version into almost every European language."

I always read this in the same sense as Dr. Bill: hubris.