Jonathan Haidt, the highly influential psychologist, is here to show us why we all find it so hard to get along. By examining where morality comes from, and why it is the defining characteristic of humans, Haidt shows why we cannot dismiss the views of others as mere stupidity or moral corruption. Our moral roots run much deeper than we realize. We are hardwired not just to be moral, but moralistic and self-righteous. From advertising to politics, morality influences all aspects of behaviour. It is the key to understanding everybody. It explains why some of us are liberals, others conservatives. It is often the difference between war and peace. It is also why we are the only species that will kill for an ideal. Haidt argues we are always talking past each other because we are appealing to different moralities: it is not just about justice and fairness - for some people authority, sanctity or loyalty are more important. With new evidence from his own empirical research, Haidt proves it is possible to liberate us from the disputes that divide good people. We can either stick to comforting delusions about others, or learn some moral psychology. His hope is that ultimately we can cooperate with those whose morals differ from our own.