In If Not God, Then What? theoretical neuroscientist Joshua Fost shows how the search for beauty is the source of both religious experience and scientific theorizing. The pleasure of seeing a beautiful face, the thrill of understanding a new idea, the sublimity of art and the power of religious transformation are all, in the end, the result of a brain that wants to make sense of the world. Weaving ideas from brain science and everyday activities - from Sunday cartoons to existentialism - Fost shows how a biological idiosyncrasy motivates them all. But if religious experience is just a special activity pattern in neurons, what should we think about its undeniable and emotionally transformative power? If everything we do is determined by physics, what is the basis for free will, or ethics? Blending receptivity to the glory of spiritual exultation with an insistence on naturalistic foundations, If Not God, Then What? breaks new ground and gives its readers insight into a compelling new worldview.