BOOK REVIEW: LET THEM IN.

The annals of logic do not lack for odd argumentative techniques. There's the argumentum ad hominem, which relies on personal attacks. There's the argumentum ad ignorantium, which suggests that what hasn't been proven false must be true; the argumentum ad novitatem, which suggests that something must be superior by virtue of being newer; and the argumentum ad crumenam, which holds that the side with the most money can safely be judged the most correct, or why else would they have so much money?The logicians forgot one, though. Cloistered in academia, which I'm told is very liberal, they may not have been often exposed to the argumentum ad Reagan, which holds that the side able to produce the most textual evidence associating Ronald Reagan with their position is the undisputed winner. That is the argumentative technique on display in much of Jason Riley's new book on immigration, Let Them In. Riley, an editorial board member at The Wall Street Journal, has produced a manifesto against a conservative movement he fears is increasingly tripping into xenophobia and anti-immigrant hysteria. And so he begins his book, and peppers it throughout, with the only voice able to calm his comrades down: Ronald Reagan's.