An amazing book which describes how our brains, by evolution, discriminate between various sources of happiness. Clearly expressed reasons for why in-group people listen to their ideology over others even if given overwhelming evidence of the other ideology being superior. As emotions control decisions, an explanation of why some actions activate our moral sensors, our emotions, while other actions which have the same outcome do not activate emotional responses. Reasons for how and why cooperative results occur even if the individual self-interest of for each player to get the maximum amount from a particular interaction are explained via morality. The author uses different tools to help explain the case of morality such as game theory, economics, philosophy and psychology. The major theme of the book is the philosophy of utilitarianism with its history, why its underrepresented and its actual meaning is given. Extremely well written. The only possible downside of the book is that sometimes the author generates questions without giving a more clear answer. For instance in the case of using what is best. The economic solution would be to use Bayesian Theory.