William's father has just died. Weary and heartsick from the loss, he takes the first flight from New York to San Francisco, dreading what promises to be an intensely painful trip. That is, until William meets Paul, the enigmatic passenger seated next to him. Paul is not an idle mind, and he plumbs William's soul about bereavement and the meaning of death. They embark on a mental foray that leads to a feral reexamination of religious beliefs and the facts of science. Science and religion are not bookends between which all of reality is compressed. Species self-organization (decentralized evolution), and self-organizing systems, laws and processes underlying human existence and behavior are not adequately accounted for in religious and scientific evaluations of cause and effect. Between Apes and Gods applies thought experiments to test the validity of doctrinal assumptions which fail to include species self-organization—it admits at least the possibility, that everything we believe to be true is not true. Between Apes and Gods is a doubter's book, a book of questions.