"I've had long and sometimes difficult discussions, especially about the singularity of the origin of Eukaryotes... A lot of people don't like that. ...[I]t's not really about what does it say about the probability of life elsewhere, although it has things to say to that. It's really about life on earth, and a lot of people are very uncomfortable with the idea of improbability... I've had quite difficult discussions with some students about that, but rarely... about life elsewhere in the Universe."