“Immoderatus fervor ad intra coërcendus”

To explain how the element of fire, after a prevailing association with antichristian attitudes such as atheism and heresy was gradually rehabilitated in early modern natural philosophy and began to be perceived as a providential agent of change, debates in medicine, natural history, chemistry and theory of matter have been called into consideration. Changes of perception toward fire and its meanings that took place in Jesuit natural philosophy and emblematics can provide additional explanations, especially if we focus on the reactions to Athanasius Kircher’s ideas and representations of the Earth’s central fire by authoritative confreres such as Pierre Gautruche, Honoré Fabri, Paolo Casati and Giovanni Battista Tolomei. At the edge of the natural philosophical domain, Franz Reinzer’s Meteorologia philosophico-politica (1697) suggests that a reappraisal of the symbolic meaning of fire as a positive fervor capable of driving man to beneficial enterprises took place in Jesuit moral and didactic literature elaborating on Kircher’s views and images propounded in his Mundus subterraneus. This notion of fire as a christianized agent, however, did not imply any concession to the innovative views on the matter of fire worked out by Seventeenth-century corpuscularists.