“as far as we know every single sentient being in the universe that’s ever believed in a god is a member of our odd little species, and almost every member of our species has believed in a god. To scientists interested in evolution and human nature, religion is a puzzle that absolutely screams to be solved.
In this book, I’ll argue that religion is not *an evolutionary puzzle* so much as *two evolutionary puzzles* that can only be solved together. First is the Puzzle of Faith: the puzzle of how Homo sapiens—and Homo sapiens alone— came to be a religious species. Second, there is the Puzzle of Atheism: how disbelief in gods can exist within our uniquely religious species.”