THE SUNDAY TIMES BESTSELLER 'Unapologetically optimistic and bracingly realistic, this is the most inspiring book on ‘ethical living’ I’ve ever read.' Oliver Burkeman, Guardian ‘A monumental event.' Rutger Bregman, author of Humankind ‘A book of great daring, clarity, insight and imagination. To be simultaneously so realistic and so optimistic, and always so damn readable… well that is a miracle for which he should be greatly applauded.’ Stephen Fry In What We Owe The Future, philosopher William MacAskill persuasively argues for longtermism, the idea that positively influencing the distant future is a moral priority of our time. It isn’t enough to mitigate climate change or avert the next pandemic. We must ensure that civilization would rebound if it collapsed; cultivate value pluralism; and prepare for a planet where the most sophisticated beings are digital and not human. The challenges we face are enormous. But so is the influence we have. 

THE SUNDAY TIMES BESTSELLER 'Unapologetically optimistic and bracingly realistic, this is the most inspiring book on 'ethical living' I've ever read.' Oliver Burkeman, Guardian 'A monumental event.' Rutger Bregman, author of Humankind 'A book of great daring, clarity, insight and imagination. To be simultaneously so realistic and so optimistic, and always so damn readable... well that is a miracle for which he should be greatly applauded.' Stephen Fry Humanity is in its infancy. Our future could last for millions of years - or it could end tomorrow. Astonishing numbers of people could lead lives of great happiness or unimaginable suffering, or never live at all, depending on what we choose to do today. As we approach a critical juncture in our history, we can make profound moral decisions about how humanity's course plays out. We can create positive change on behalf of future generations, to prevent the use of catastrophic weapons and maintain peace between the world's great powers. We can improve our moral values, navigating the rise of AI and climate change more fairly for generations to come. The challenges we face are enormous. But so is the influence we have. If we choose wisely, our distant descendants will look back on us fondly, knowing we did everything we could to give them a world that is beautiful and just.

This is an open access title available under the terms of a CC BY-NC-ND 4.0 International licence. It is free to read at Oxford Scholarship Online and offered as a free PDF download from OUP and selected open access locations. Very often we're uncertain about what we ought, morally, to do. We don't know how to weigh the interests of animals against humans, how strong our duties are to improve the lives of distant strangers, or how to think about the ethics of bringing new people into existence. But we still need to act. So how should we make decisions in the face of such uncertainty? Though economists and philosophers have extensively studied the issue of decision-making in the face of uncertainty about matters of fact, the question of decision-making given fundamental moral uncertainty has been neglected. Philosophers William MacAskill, Krister Bykvist, and Toby Ord try to fill this gap. Moral Uncertainty argues that there are distinctive norms that govern how one ought to make decisions. It defends an information-sensitive account of how to make such decisions by developing an analogy between moral uncertainty and social choice, arguing that the correct way to act in the face of moral uncertainty depends on whether the moral theories in which one has credence are merely ordinal, cardinal, or both cardinal and intertheoretically comparable. It tackles the problem of how to make intertheoretical comparisons, discussing potential solutions and the implications of their view for metaethics and practical ethics.