I question whether he is really a history buff. All the history buffs I’ve known are aware of work on both sides of an issue and many of them are able to recite the names of authors from memory, e.g. “For the world-is-flat issue, you gotta start with the Washington Irving bio and then go straight to Russell’s little gem”. If this guy isn’t aware of the debunking literature then he’s no buff. And five minutes on
Amazon.com will dredge up plenty.
Another tack that at least silences these half-educated cranks is to ask naive questions that expose their fundamental ignorance about key issues. For example:
BIL: The crusades killed many innocent people for no reason.
Paul: ORLY? What were the Crusades?
BIL: Where the pope would guarantee you going to heaven if you go kill Muslims.
Paul: What Muslims?
BIL: In the Middle East.
Paul: What were Muslims doing in the Middle East? I thought that whole area, from Morocco to Iraq, and up through Turkey, was all Christian.
BIL: No, Muslim.
Paul: Well how did they all suddenly become Muslim?
BIL: They converted.
Paul: They converted? I thought it was early medieval Islamic expansionism under the Caliphs.
BIL: Well that too.
Paul: Did they kill many innocent Christians for no reason?
BIL: Nevermind.