Andreas Blank (Humboldt University of Berlin)

From an isolated reading of the Hypothesis physica nova (1670-71), it might look as if Leibniz by this time endorsed a quite straightforwardly materialistic and mechanistic ontology. Moreover, as the title of Leibniz’s work suggests, the method followed there seems to be simply a version of hypothetico-deductive reasoning. However, the puzzling presence of the Aristotelian notion of ether, and the way Leibniz combines this notion with the Stoic notion of pneuma and the Averroistic notion of a universal active intellect, is one of the features of the Hypothesis physics nova that cannot be explained adequately from this viewpoint. This has led Christia Mercer to a radical interpretation both of Leibniz’s methodology and of his theory of matter. According to her interpretation, Leibniz by the winter of 1670-71 embraced a method of conciliatory eclecticsm. Moreover, she claims that by this time Leibniz transformed the passive principle in corporeal substance into a collection of mind-like substances. (Cf. Mercer, Leibniz’ Metaphysics. Its Origins and Development, New York: Cambridge University Press, 2001, especially p. 256).

The present paper has the aim to defend a different line of interpretation. If the Hypothesis physica nova is read on the background of Leibniz’s correspondence with Henry Oldenburg and Jakob Thomasius, it becomes clear that in the winter of 1670-71 Leibniz did not spiritualise matter. Although he uses the terminology of "pneuma", "spirit of God", "world soul", etc., the direction of analysis is not one that eliminates the physicalistic notions of extension, impenetrability, resistance, striving etc. in favour of notions describing features of immaterial entities. Rather, terms traditionally denoting immaterial substances are analysed by reducing them to properties of physical matter. This strategy comes close to the view of the nature of ether in the work of mechanistic Aristotelians such as Kenelm Digby and Thomas White, and therefore is compatible with Hobbes’ and Descartes’ theories of subtle matter. Moreover, although Leibniz tries to reconcile aspects of different philosophical traditions, his method is not adequately characterised as eclectic. This becomes particularly clear through the role his theory of reflective knowledge plays in his early analysis of the nature of mind and matter. It is the role that categories based on the analysis of the structure of mental operations have for the analysis of the nature of matter that both makes Leibniz’s theory of matter more than an eclectic one. Moreover, it explains why Leibniz did not make the step towards a reinterpretation of the passive principle of corporeal substances in terms of collections of immaterial entities.

Andreas Blank earned his PhD at the Center for Philosophy and Philosophy of Science at the University of Konstanz in 1998. Since then, he has been Research Associate at the Department of Philosophy of the Humboldt University of Berlin, Visiting Fellow at the Center for Philosophy of Science at the University of Pittsburgh, and presently is Visiting Lecturer at the Humboldt University and the Free University of Berlin. His recent and forthcoming publications include Der logische Aufbau von Leibniz’ Metaphysik, Berlin—New York: De Gruyter 2001, and articles on Leibniz and on the early Wittgenstein in Grazer Philosophische Studien, Philosophia, Studia Leibnitiana, Leibniz Review and British Journal for the History of Philosophy.