Rucker discusses the thesis that everything is a computation, a more complex form of cellular automata, and what that would mean for philosophy. Along the way, he fills us in with a reasonable background in theories of computation, cellular automata, philosophy, and other computer science and mathematical topics.

From that description, the book may sound a bit dry, but it’s really quite enjoyable and engaging. Rucker starts each chapter with a short short story related to the chapter’s subject matter, and he sprinkles bits of his other (fictional) writing in where appropriate, as well.