You are telling me that I did something because I was going to do something.”“Well, didn’t you? You were there.”“No, I didn’t—no… well, maybe I did, but it didn’t feel like it.”“Why should you expect it to? It was something totally new to your experience.”“But… but—” Wilson took a deep breath and got control of himself. Then he reached back into his academic philosophical concepts and produced the notion he had been struggling to express. “It denies all reasonable theories of causation. You would have me believe that causation can be completely circular. I went through because I came back from going through to persuade myself to go through. That’s silly.”“Well, didn’t you?
Robert A. Heinlein, By His Bootstraps
causation, spacetime, time-travel