Atheism has been on the rise in the West for several decades, but its roots, including those belonging to secularism, agnosticism, and freethought, run deep in Western history, philosophy, and thought. Drawing on a multitude of sources from a number of disciplines, S. T. Joshi outlines the natural origins of religious belief in primitive times and charts the slow development of secular accounts of natural phenomena in the Greco-Roman world. Adopting the "Christ myth" theory, he surveys the emergence of a new faith—Christianity—that grew out of Judaism and explores its evolution through the medieval period. He then examines the increasing schisms within the church and conflicts between religious and political entities that caused a fracturing of the monolith of Christianity and the birth of the Renaissance, which not only brought to light the literary glories of the Greco-Roman world but also led to a scientific resurgence and the development of a secular view of the cosmos. By the end of the sixteenth century, as he concludes, the stage was set for the emergence of a worldview free of religion.