“You’ve nothing to back it up with. Even if you’re right, I’m still right in not believing without evidence.”
Chapter 28 (p. 172)
Roadmarks (1979)
Quotes from book
Roadmarks

The Road runs from the unimaginable past to the far future, and those who travel it have access to the turnoffs leading to all times and places--even to the alternate time-streams of histories that never happened. Why the Dragons of Bel'kwinith made the Road--or who they are---no one knows. But the Road has always been there and for those who know how to find it, it always will be! Dizzying in its virtuosity, gripping in its kaleidoscopic treatment of time, character, and action Roadmarks is a dazzling achievement.
“After signing it, he added the postscript: By the time you read this, you will already be dead.”
Source: Roadmarks (1979), Chapter 27 (p. 162)