Really, what IS the optimum time for a philosophical/people’s treatise on our ethical responsibilities for future generations and the risks we need to act on now? Although this is not a topic that had been on my radar, having read “The Precipice: Existential Risk and the Future of Humanity,” I would say the optimum time is NOW. British moral philosopher Toby Ord has exhaustively weighed up these weighty issues—he must be a prodigious reader, half the book is notes, references, resources, etc.—and cast a sober, analytical net into the future. Dedicated to the future upside promise for the human race, the book is nonetheless a kaleidoscopic look at the various big risks threatening it, from nuclear weapons to the climate crisis, artificial intelligence to pandemics, asteroids to super volcanoes. The author surveys the risks and even ascribes rough probabilities (something that appeals to an ex-actuary like me), with some surprising results, before positing an ethical stance and then proposing grand strategies and offering individual ways to contribute. Anyone reading The Precipice will surely argue with this risk assessment, that moral standpoint, and even those strategies/tactics, but with its rigor, fluid style and clear-sightedness, this book performs a valuable public service that is bewilderingly enjoyable to read and absorb. Much recommended.