I ran into Peter Singer recently – or at least we smiled at each other as our paths crossed in a beachside car park. Although we have friends in common, I didn’t stop to introduce myself. I was caught up in a conversation, but I also momentarily feared I might have mistaken him for somebody else: in a wetsuit, everyone looks a little bit different and a little bit the same. I know he surfs at that spot, though, so it almost certainly was Australia’s most famous philosopher checking the swell. My friend and I were returning from taking a look and had concluded that the waves were too small and messy. Perhaps we should have shared that information, but then we might have denied him a certain pleasure; a few minutes spent gazing at the ocean can never be counted as wasted time. Seeing Peter Singer at the beach reminded me of an event at Melbourne’s Wheeler Centre a couple of years ago. His presentation that day, and particularly his answer to a question from a woman named Rachel, has nagged at me ever since.