I first met Derek Parfit the summer I was 19, when my college boyfriend and I spent a day visiting Oxford. Parfit’s Reasons and Persons was the only thing written by a living person on our first-year philosophy syllabus at Yale. Passing All Souls College, we went to the porter’s lodge and asked, absurdly, if we could see him. The porter said Parfit was teaching a seminar in the Old Library. We stood outside the door, pressing our ears to it, hearing nothing but murmurs, debating whether or not to go in. Eventually the seminar ended and people started to file out. Realising we had no idea what Parfit looked like, we asked every man leaving the room if he was Derek Parfit. They all laughed: they must have been twenty-something graduate students. Finally, out came a man with a mane of white hair and a bright red tie tucked into his trousers, wielding a large Smirnoff vodka bottle. We introduced ourselves.