Although science is viewed by most today as a bastion of reason and evidence, the origins of our modern scientific method have some of their roots in the irrational-seeming world of the occult: alchemy, astrology and magic. Belief in the occult goes all the way back to the ancient world, but it remained prevalent into the modern era. During the “Scientific Revolution” of the seventeenth century, the natural world was still believed to be full of secret knowledge and powers, knowable and accessible only by the very wisest and most pious scholars. The “occult sciences” seemed to offer a way of penetrating Nature’s most interesting and useful secrets, as well as a path to controlling them. Ultimately, the occult sciences were believed to hold the key to harnessing and manipulating the boundless hidden powers of Nature itself, and many of the most famous scientists of the era actively pursued them.