Jean Gallois

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Jean Gallois was a French scholar and abbé. He was a client of the Controller-General of France Jean Baptiste Colbert. Gallois was a librarian and geometer in the service of the French Académie Royale des Sciences (1669), and lectured (1668) mathematics at the Paris Collège royal. He was elected (1672) Fellow of the Académie française. His friends included Pierre Daniel Huet and Henri Justel. Gallois’s most noted work is Breviarium Colbertinum (1679).

Leibniz wrote with much constraint to Gallois about his encounter with Spinoza and their discussions on metaphysics, probably because he was afraid that ultimately he might be associated with his radical philosophy. In his letter to the abbé, he explicitly rejects Spinoza’s inflammatory demonstrations, but is also troubled to hide his fascination with his formidable erudition and outstanding intellectual abilities in biblical criticism and metaphysics:

Spinoza died this winter. I saw him when passing through Holland, and I have discussed with him several times and at great length. His metaphysics is strange, full of paradoxes. Among others things, he believes that the world and God are just only one single substance, that God is the substance of all things, and that all creatures are nothing but modes or accidents. But I observed that some of the alleged proofs that he showed me are not exactly right. It is not as easy as one might think to give true demonstrations in metaphysics. Nonetheless, some of his [demonstrations] are very beautiful.

Source: Leibniz to Gallois, [September] 1677; Leibniz, AA, 2:1, p. 568, no. 158; see also Walther and Czelinski, vol. 1, p. 331, no. 139.


Gottfried Wilhelm Leibniz


Pierre Daniel Huet


Henri Justel