One of my favourite parts of Will MacAskill’s What We Owe The Future was a provocative thought experiment at the start of the introduction. But I thought it needed some illustrations, so…
Imagine living, in order of birth, through the life of every human being who has ever lived. [...] Your life lasts for almost four trillion years in total. For a tenth of that time, you’re a hunter-gatherer,
and for 60 percent you’re an agriculturalist.
You spend a full 20 percent of your life raising children,
a further 20 percent farming,
and almost 2 percent taking part in religious rituals.
For over 1 percent of your life you are afflicted with malaria or smallpox.
You spend 1.5 billion years having sex and 250 million giving birth.
You drink forty-four trillion cups of coffee.
[...]
For about 10 percent of your life you are a slaveholder; for about the same length of time, you are enslaved.
You experience, firsthand, just how unusual the modern era is. Because of dramatic population growth, a full third of your life comes after AD 1200
and a quarter after 1750.
At that point, technology and society begin to change far faster than ever before. You invent steam engines, factories, and electricity. You live through revolutions in science, the most deadly wars in history, and dramatic environmental destruction. Each life lasts longer, and you enjoy luxuries that you could not sample even in your past lives as kings and queens. You spend 150 years in space and one week walking on the moon.
Fifteen percent of your experience is of people alive today.
That’s your life so far—from the birth of Homo sapiens until the present. But now imagine that you live all future lives, too. Your life, we hope, would be just beginning. Even if humanity lasts only as long as the typical mammalian species (one million years), and even if the world population falls to a tenth of its current size, 99.5 percent of your life would still be ahead of you.
On the scale of a typical human life, you in the present would be just five months old. And if humanity survived longer than a typical mammalian species—for the hundreds of millions of years remaining until the earth is no longer habitable, or the tens of trillions remaining until the last stars burn out—your four trillion years of life would be like the first blinking seconds out of the womb. The future is big.