Challenging, with several powerful arguments, some of our deepest beliefs about rationality, morality, and personal identity, Derek Parfit claims that we have a false view about our own nature. It is often rational to act against our own best interests, he argues, and most of us have moral views that are self-defeating. We often act wrongly, although we know there will be no one with serious grounds for complaint, and when we consider future generations it is very hard to avoid conclusions that most of us will find very disturbing.