A well-established historiography connects the metaphysical model held by the Jesuit Benet Perera (Pererius) to the metaphysics (actually one of the first ontologies, in the proper sense of the word, in history) of the Calvinist Rudolph Goeckel (Goclenius). An extensive study of the works of the two authors confirms this connection and allows us to understand better the fundamentals of Goclenius's position. Interestingly, it also appears that after it is removed from rational theology, Goclenius's ontology does not seem to acquire the status of neutral and universal science that its proponent sought. Rather, it still is dependent on the definitions provided by other disciplines, such as logic and mathematics