During the past two decades, several good nonfiction writers have taken aim at the mental processes that underlie human religion. Their books sold well, but left their more incisive readers still wanting to know how evolution produced the religious mind. I have in hand the answer to that question. Here's the shortest possible summary: It is hard to accept at face value that religion, with its huge attendant costs to the species, could have emerged from the process of natural selection. As we all know, though, all of life's features result from evolution by natural selection. It cannot be otherwise. This, then, is the interesting paradox, and what resolves it is this: religion makes a man a better fighter. This simple fact has produced vast evolutionary consequences. The capacity for mortal combat, that has been part of the human scene since the very beginning, gets a boost. The mutation that produced the capacity for religion arrived more recently. It changed the world by biasing the outcome of each fight to the death, and there were a lot of such fights. The winner's genes remained in the gene pool, and the loser's were removed. The winner's genes tended to be the ones that included the capacity for religion, so religion got a boost, too. Once this started, there was no stopping it. The warlike and god-fearing ways of today's human are echoes of those mortal combats, resonating down to us over thousands of generations and millions of fights to the death. It's something we'd all do well to be aware of. Book-buying thinkers whose shelves already support works by Dawkins, Dennett, Pinker, Hitchens, Harris, Darwin et al. will find my book a very valuable addition. It presents a plausible answer to an important question, one that those other worthy authors skirted around, but left unasked and unanswered.That said, this book is NOT an argument for or against religion.