The occult is routinely dismissed in our times as the province of quacks, the irrational, and the superstitious. But during the Renaissance, many of the best minds in Europe studied the philosophy and science of the occult. The period witnessed an outpouring of systematic philosophical and scientific treatises on the occult. References to the occult pervade the works of Shakespeare and other literary writers of the time. Many scholars believe that The Occult Philosophy and the Occult Sciences, with their search for hidden causes, played a decisive role in the rise of modern science. In this special Halloween week episode, John and Ken delve into the Occult Philosophy with Christopher Lehrich from Boston University, author of The Occult Mind: Magic in Theory and Practice.