Jonathan Haidt spent two decades as a social psychologist studying how people arrive at moral judgments, including fieldwork in Brazil and India that convinced him the standard Western account was too narrow. The Righteous Mind, published in 2012, applies that work to the question in its subtitle: why good people are divided by politics and religion.
The first part argues that intuition comes first and strategic reasoning second. Haidt's image is a rider on an elephant. The elephant leans, and the rider, who is convinced he is steering, supplies the justification afterwards. He draws on studies of moral dumbfounding, in which people stay certain an act was wrong long after every reason they offered for it has been taken apart. If judgment works this way, better evidence is rarely enough on its own to move anyone.
The second part sets out Moral Foundations Theory, the piece of the book most often cited since. Haidt proposes six foundations that moral systems draw on: care, fairness, liberty, loyalty, authority and sanctity. Educated Western readers, and liberals in particular, tend to reason almost entirely from care and fairness, while conservative morality spreads its weight across all six. He does not claim one arrangement is correct. His point is that a two-foundation morality has no way to read a six-foundation one, which leaves each side unable to hear the other.
The third part turns to groups. Humans on this account are mostly self-interested but able to flip what Haidt calls a hive switch, subordinating themselves to something larger, and religion, patriotism and party politics are the machinery that flips it. This is where the book's best-known line comes from: morality binds and blinds. The same instinct that makes cooperation possible inside a group makes the group's opponents unintelligible from outside it.
Haidt closes on the practical question the book was written for, which is how people who disagree about politics and religion might argue to better effect. It followed The Happiness Hypothesis (2006) and was a New York Times bestseller.
