One morning in 1980, during a nine-month stay among the Pirah�, I awoke to yelling, crying, and whooping near the river's edge, about fifty feet from where I was trying vainly to sleep. I went to the crowd, which included nearly every man, woman, and child in the village. They were all pointing across the river and some were crying, some were yelling, and all were acting as though what they were seeing was very frightening. I looked across the river, but I could see nothing. I asked them what they were fussing about. One man answered increduously, 'Can't you see him there?' 'I see nothing. What are you talking about?' was my response. 'There, on the other bank, on that small strip of beach, is 'igaga� a mean not-blood-one. There was nothing on the other side. But the people insisted that he was there in full view. This experience has haunted me ever since. It underscored how spirits are not merely fictional characters to the Pirah�, but concrete experiences.