Last winter, William MacAskill and his wife Amanda moved into a Union Square apartment that I was sharing with several friends in New York. At first, I knew nothing about Will except what I could glean from some brief encounters, like his shaggy blond hair and the approximation of a beard. He was extremely polite and devastatingly Scottish, trilling his “R”s so that in certain words, like crook or the name Brooke, the second consonant would vibrate with the clarity of a tiny engine.
MacAskill, I soon discovered, was a Cambridge-and Oxford-trained philosopher, and a steward of what’s known as effective altruism, a burgeoning movement that has been called "generosity for nerds." Effective altruism seeks to maximize the good from one's charitable donations and even from one’s career. It is munificence matched with math, or, as he once described it to me memorably, “injecting science into the sentimental issue of doing good in the world.”
Up to that point, I would have described my interest in charity as approximately average. I certainly hadn’t thought deeply about my donations long before I met MacAskill. I'd volunteered for music-education programs because I liked music, but this felt not like an exercise in selflessness, but rather an expression of my personal identity, like wearing clothes.