Jimmy Breslin

Don't try to tell Namath's people on First Avenue about Babe Ruth, because they don't even know the name. In fact, with the young, you can forget all of baseball. The sport is gone. But if you ever have seen Ruth, and then you see Namath, you know there is very little difference.

The historical novelist has to consider what has actually happened, while the SF writer is dealing in possibilities, but they are both in the business of imagining a world unlike our own and yet connected to it.