. . . if you go mad, do you know you’ve gone mad? If you don’t, how do you know you’re not mad?
“It’s not just that things in the future can affect things in the past,” he said. “Things that didn’t happen but might have happened can . . . affect things that really happened. Even things that happened and shouldn’t have happened and were removed still have, oh, call ’em shadows in time, things left over which interfere with what’s going on.” —The Last Continent