Three Sentences That Could Change the World — and Your Life
About this episode
Ezra Klein interviews Oxford philosopher William MacAskill, a leading figure in effective altruism, about his book What We Owe the Future and the case for longtermism. MacAskill argues that future people matter morally, could vastly outnumber everyone alive today, and that present choices — on climate, biotechnology, nuclear weapons, artificial intelligence, and political institutions — could shape civilization for millennia. He discusses existential risks, from engineered pandemics to misaligned AI, and the danger of lock-in, where totalitarian control could freeze bad values in place forever. Klein presses him on whether this future-focused outlook neglects present suffering, the arrogance of forecasting centuries ahead, and how anyone should act when the stakes are cosmic but the uncertainties enormous. They also explore moral progress — how abolitionism and declining violence were driven by dedicated moral weirdos — and what it means to be a good ancestor.