The One or the Many? : Boscovich, Kant, and the Metaphysical Puzzle of Space

The supplement »De Spatio et Tempore« to Roger Boscovich’s Theoria philosophiae naturalis (1763), together with some notes to Stay’s Philosophia recentioris, contains the more comprehensive explanation he gave to the concept of space in itself (Suppl. I) and in its relationship to human knowledge (Suppl. II). As well known, Boscovich wanted to reach a compromise between Leibniz »relational« space conception and Newton’s views about space as a sheer system of coordinates. Boscovich was not the only one in 18th century scientifi c and scholarly community to seek for such a via media between the two great masters of 17th and 18th–centuryscience. Another interesting, independent and — to some extent — opposite case was Immanuel Kant, who from an initial inclination to Leibniz’ and Euler’s relationalism developed in his Critique of Pure Reason (1781, 1787) a space conception mostly due to Newton’s idea of an absolute space (a conception in which, however, the Leibniz–Euler fl avour is not completely unperceivable). In Kantian final idea, the plurality of the world is cancelled out by the uniqueness of an order superimposed to the things by the space–time intuition. On the other hand, Boscovich shapes in his Theoria a general »pluralistic view« (but one in which Newton’s influence is not entirely absent) where the order of things is an emergent property of their interactions (see for instance the »doctrine of modes« expressed in Suppl. I, 1–4). The broadness of this perspective is also shown by his rejection of the idea of the continuity of matter and space in the Theoria itself and in some important letters (mostly to his friend G. S. Conti) where he tried to give a complete and plain account of the philosophical underpinnings of his natural philosophy.