Leibniz, de Volder and Spinoza's Ghost

The correspondence with the Dutch physicist Burcher de Volder is one of the most important in Leibniz’s career. Behind their discussions on the main topics of the exchange – such as the relationship between physics and metaphysics, or the concepts of matter, force, substance – the reader can detect the presence of a third silent interlocutor, whose name is evoked at some crucial points, namely Spinoza. The aim of this paper is not to take a position in the old debate on de Volder’s alleged crypto-Spinozism, but to reconstruct where and how in the correspondence some themes or arguments appear which objectively can remind Spinoza’s stance, and how they are received by Leibniz