If you went back in time with a copy of, say,
Lord Of The Rings, and submitted it for publication under your own name before JRR ever even thought of it, then he will obviously never write it (since it is already written).
You have just created a bestselling book that was never actually written.
The thing is, it was written, just in a different
timeline. One theory suggests that even if
time-travel were possible, a
human would only be able to travel back a few times (unless they were short distances) before he would become
confused and
disorientated, and forget which timeline he was currently experiencing.
Travel forward would not pose this problem, since you would not move into a different timeline.
TotalRetard - time travel is most certainly possible, at least forwards. Backwards is another story.