There's no way to get from the point in Hemn space where we are now, to one that includes pink nerve-gas-farting dragons, following any plausible action principle. Which is really just a technical term for there being a coherent story joining one moment to the next. If you simply throw action principles out the window, you're granting the world the freedom to wander anywhere in Hemn space, to any outcome, without constraint. It becomes pretty meaningless. The mind... knows that there is an action principle that governs how the world evolves from one moment to the next—that restricts our world's path to points that tell an internally consistent story. So it focuses its worrying on outcomes that are more plausible...

Orolo and Erasmas, Part 4, "Anathem" - Anathem (2008)