This book seeks to answer a very straightforward question: How did religion come to be? A common way of addressing such a question is to go back to a time prior to the existence of the phenomenon you wish to explain and show how various factors operated to bring the phenomenon into existence. To understand how the Roman Empire came to be, for example, one might show how the pre-empire conditions of the ancient Mediterranean world made Rome’s emergence possible or even inevitable. This book treats religion the same way. But this immediately raises a question: Can we truly envision a world prior to religion? As far back as we can trace human history, there has always been religion. Indeed, some believers regard religion as a divine gift transcending human history. Treating it as a consequence of the same haphazard stew of historical forces that drive human affairs seems to border on sacrilege.