chapotraphouse

The point of the book is that even the God emperor (the guy I was talking about, Paul Atriedes) doesn't get to make his own future. He gets to choose a future, which is incredibly powerful, but he never gets to make one that satisfies everything he would ideally want.

Edit: It's a subtle difference, but it is the driving problem through all of the rest of the Dune books, with future emperors growing increasingly esoteric and warped in their attempts to use spice to predict, and more importantly shape, the future, a path that Paul sees as unstable but inevitable.