For centuries men have confronted a false alternative of enormous historical import: religious mysticism versus philosophical skepticism. Greece once faced this dilemma; in the end her philosophers turned to skepticism, and her population to orthodox religion. Without a rational alternative, religious certainty beat skepticism hands-down. America is now locked in such a struggle, between the religious Right and the nihilistic Left. This lecture will use the example of the later Roman Empire to demonstrate the outcome of a similar struggle, and its consequences, on a world-scale. It was in the third century A.D. that the last gasp of pagan Greek philosophy—Neo-Platonic mysticism—cleared the way for the intellectual and moral takeover by Augustinian Christianity. It was the default of the philosophers—and their grant of credence to the mystics—that set the foundations for the Dark Ages.