Election Day is more than a year away, yet already the presidential campaigns have begun. Given previous contests, we should most likely expect a good deal of disingenuous diatribes and debates—some of it from the candidates, and even more of it from their supporters. In anticipation of the coming ugliness, it seems as good a time as any to learn something about civil disagreement and the possibilities of persuasion from an unlikely source: the Puritans.