Moral theories can be distinguished not only by the answers they give but also by the questions they ask. Utilitarianism's central commitment is to the promotion of well-being, impartially considered. This commitment shapes utilitarianism in a number of ways. If scarce resources should be directed where they will best promote well-being, and if theoretical attention is a scarce resource, then moral theorists should focus on topics that are most important to the future promotion of well-being. A theme of this Element is that, as times change, the priorities (both practical and theoretical) of utilitarianism also change. Questions that were once theoretical curiosities move centre stage. And themes from earlier utilitarians that have become unfashionable may come to the fore again. Utilitarianism is a living tradition, not an abstract set of timeless principles or a purely historical artefact.
A somewhat terrifying but also eye-opening and perspective-shifting read. Defends a form of future-oriented, collective, ideal utilitarianism focused on teaching the correct norms to the next generation. It was an enjoyable and fascinating book.
He takes seriously the possibility of broken futures (human lives are, on balance, not worth living), virtual futures (humans are plugged into a virtual world or experience machine), and digital futures (humans are uploaded to computer or replaced by digital beings), and the implications for ethics.
He extensively discusses various problems in population ethics (like Derek Parfit's Repugnant Conclusion), as well as the ethics of procreation. Finally, he discusses existential threats of human extinction, and that this might should dominate ethical reasoning (since the positive value of continued human existence for millions of years might otherwise be lost).
Overall, this book really forced me to grapple with the range of problems any ethical theory needs to consider, especially regarding uncertainty about the future.
One surprising example of this reasoning he mentions is that rights-based theories assume people having absolute rights would also be good for future people, but there are credible futures, such as those of extreme scarcity, where certain such absolute rights would make things worse off (e.g. lead to much greater death), undermining absolute rights in the first place.