I was flying to a seminar in New Hampshire a couple of summers ago. I was sitting in the plane next to a Philosophy Professor from Harvard. He told me this story about how every morning he takes a leak right after his three-hour philosophy class. He flushed the toilet, there'd be this tiny brown spider fighting for its life against the swirling water. He came back the next day, flush. Same spider, clawing its way back from oblivion. A week goes by, he decides to liberate the spider. Grabs a ...