Leibniz on Spinoza's Tractatus de Intellectus Emendatione

This chapter studies Leibniz’s engagement with the Treatise on the Emendation of the Intellect (TIE). In May 1678, Leibniz wrote to his friend Ehrenfried Walther von Tschirnhaus: “Surely you do not ignore that the posthumous works of Spinoza have been published. Among them there is a fragment On the Emendation of the Intellect, but he stops exactly at the place where I expected the most” (A II, i, 413). This passage constitutes the only direct evaluation of Spinoza’s TIE by Leibniz that we know of. Leibniz’s evaluation expresses disappointment, and one wonders what exactly it was that Leibniz so eagerly expected to learn at the point where Spinoza’s text breaks off. Lærke attempts to answer this question by reconstructing Leibniz’s reading of the TIE on the basis of marginal notes and the context of his engagement with Spinoza’s philosophy in the latter half of the 1670s.