What We Owe the Future by William MacAskill review – a thrilling prescription for humanity

Unapologetically optimistic and bracingly realistic, a philosopher's guide to ethical living' for dangerous times

Lately I'm getting the feeling that I came in at the end," Tony Soprano tells his therapist at their first session, and it's natural to feel the same about your place in human history: that these are the twilight years. Hundreds of millennia of human activity stretch back behind us - the stone age and the bronze age and the iron age, the ancient world, the middle ages and onwards, culminating in today - whereas our mental image of our species' future tends either to be hazy or, in the event of an extinction-level catastrophe, terrifyingly short.

But there is another way to see things. Even if the world population were to fall by 90%, and if humans survive no longer than the average mammalian species, a million years in total, then 99.5% of all human experience has yet to be lived. If we can dodge the aforementioned catastrophe - a big if", obviously - then a staggeringly huge proportion of humanity's time on Earth is almost certainly yet to come.