Athanasius Kircher has a fair claim to have been the most learned German-born writer of his century: his works on Egyptology, music, optics, geology, linguistics, and comparative religion are all definitive for their time. But history has not been kind to him for several reasons. First, he wrote only in Latin, while other scholars were turning to the vernacular. Second, the breadth of his interests makes it almost impossible to appreciate his work as a whole. Third, his adherence to Christian Hermetism rooted his thought in a set of assumptions that the learned world was discarding; among these assumptions were the descent and ascent of the soul, the doctrine of correspondences, and the existence of occult powers. Yet, while his work was a tardy monument to the Renaissance ideal of universal knowledge, its celebration of nature opened new fields of study that heralded the age of secular science...