Tying the Double Metaphysics of Johannes Clauberg: Ontosophia and Rational Theology

The German philosopher Johannes Clauberg (1622–1665) was the first academic teacher who attempted to put the philosophy of René Descartes (1596–1650) at the basis of all disciplines of the traditional curriculum of studies, that is, to establish a Cartesian Scholasticism. To this aim, he developed a first philosophy, i.e. a metaphysics including rational-theological arguments, which was based on Descartes’s Meditationes de prima philosophia (1641). By it, Clauberg attempted to provide philosophy with a foundation, namely with a demonstration of the reliability of clear and distinct knowledge. Moreover, he elaborated a comprehensive logical theory showing how Descartes’s rules of the method could be completed by a Scholastic-inspired theory of definition, division and syllogism. Nevertheless, Clauberg maintained in the corpus of philosophical disciplines a metaphysics dealing with the meanings of ‘being’. Accordingly, he developed a twofold metaphysics: on the one hand, a discipline concerned with the principles of thought and rational theology, being this a philosophia prima in the order of sciences. On the other hand, a metaphysics dealing with the most abstract notions of being, viz. an ontosophia, to be studied at the end of the philosophical curriculum. Building on the account of Clauberg’s work provided by Massimiliano Savini, in this paper I explore the relations between Clauberg’s philosophia prima and ontosophia: after clarifying the overall plan of his philosophy, and presenting some examples of metaphysical arguments belonging to the philosophia prima, I argue that Clauberg’s ontosophia, despite being conceived as the most abstract of the philosophical sciences, plays a foundational role with regards to metaphysics as philosophia prima by unveiling its conceptual assumptions.