Theatres of the unseen: The Society of Jesus and the problem of the invisible in the seventeenth century

This dissertation explores a quiet but constant preoccupation with the invisible or hidden parts of the natural world on the part of Jesuit authors in the seventeenth century. I contend that the invisible was problematic for early modern thinkers because it disrupted the acquisition of certain knowledge of causes, and because it obscured the boundaries between different kinds of phenomena and agencies in the world. As priests and theologians, the Jesuits were already committed to the conceptualization of invisible and intangible subjects such as the divine presence, and their interest in hidden or invisible phenomena and forces in the natural world grew, I argue, out of this pre-existing interest in the unseen.;I explore Jesuit works devoted to the magnet, the unguentum armarium or weapon salve, and both natural and artificial magic in an attempt to understand how these authors approached the invisible and resolved some of its associated problems. The emphasis on vision and the use of imagery in Jesuit meditative texts was adapted to the study of magnetism, when authors used similar strategies to render the invisible force of the magnet visible and comprehensible and thus fashioned an epistemology of the unseen. When they discussed the controversial unguentum armarium, Jesuit authors used this particular phenomenon to reaffirm the ontological boundaries between different kinds of agency and force in the natural world, preserving the important distinction between the natural and supernatural realms while publicly reinforcing their status as philosopher-theologians capable of recognizing and demonstrating these distinctions. Later in the seventeenth century, particular Jesuits focused on the uses of artifice in their efforts to reveal and master the hidden processes of Nature, thereby resolving in a public and demonstrable fashion the problems posed by the invisible.;I conclude with some of the deeper implications for the historiography of Jesuit science raised by this project, and give some thought to the way in which this focus on the invisible can be reconciled with the shifting intellectual tides of this period.