pairs...................

 

But it was more than the historically complex issue of the haves and have-nots.  It was a fundamental question of ignorance and intolerance.  Hemingway had always considered ignorance and intolerance to be like commas, because you often found them in pairs, and almost never did you find one, ignorance, without its evil twin, intolerance.

-David Baldacci, The Camel Club