This remarkable book, written in the layperson's language, leaves no room for unproven ideas and instead seeks hard evidence for the existence of God. The author, a sympathetic critic and observer of religion, finds instead a physical universe that exists reasonlessly. He attributes good and evil to biology, not to God. In place of theism, the author gives us the knowledge that the universe is intelligible and that we are grownups, responsible for ourselves. He finds salvation in the here and now, and no ultimate purpose in life, except as we define it.