Only one book (Pérez-Reverte)

...there is nothing more despicable or more dangerous than the malevolent individual who goes to sleep every night with a clear conscience. That is true evil. Especially when paired with ignorance, superstition, stupidity, or power, all of which often travel together.

And worst of all is the person who acts as exegete of The Word—whether it be from the Talmud, the Bible, the Koran, or any other book already written or yet to come. I am not fond of giving advice—no one can pound opinions into another's head—but here is a piece that costs you nothing: Never trust a man who reads only one book.

Arturo Pérez-Reverte, Purity of Blood