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Late Winter/ Early Spring Lessing introduced to Mendelssohn by their mutual acquaintance, the Jewish physician Aaron Salomon Gumpertz (1723-1769). The two play chess in a scene that would later be reprised in Nathan der Weise. As an early fragment (“Das Christhenthum der Vernunft”) attests, Lessing had already begun to toy with Spinozist themes.
16 October In a letter to Johann David Michaelis, Lessing writes of Mendelssohn: “Seine Redlichkeit und sein philosophischer Geist läßt mich ihn im voraus als einen zweiten Spinoza betrachten, dem zur völligen Gleichheit mit dem ersten nichts als seine Irrtümer fehlen werden.” (Letter 62, FA 11.2:58-9, here 58)
Early Spring In his first book, Philosophische Gespräche, which Lessing published anonymously and without Mendelssohn’s knowledge or permission, Mendelssohn offers the first German-language, non-demagogical treatment of Spinoza’s philosophy.
17 April Lessing informs Mendelssohn of his thoughts on Leibniz and Spinoza that would be expounded upon in his essays “Durch Spinoza ist Leibniz nur auf die Spur der vorherbestimmten Harmonie gekommen” and “Über die Wirklichkeit der Dinge außer Gott.”
6-10 July Jacobi visits Lessing in Wolfenbüttel. They begin their discussion of Spinoza.
10-12 August Jacobi returns to Wolfenbüttel for further discussions.
12-15 August Lessing travels with Jacobi to visit Johann Wilhelm Ludwig Gleim in Halberstadt. Lessing writes ἕν ἐγὼ καὶ πάντα (hen ego kai panta, I am one and all) on Gleim’s wallpaper.
15 February Death of Lessing. Mendelssohn begins to consider writing a literary tribute to his departed friend.
Fall Christian Wilhelm von Dohm publishes Ueber die bürgerliche Verbesserung der Juden.
Fall Jacobi anonymously publishes Etwas, das Lessing gesagt hat: Ein Commentar zu den Reisen der Päpste, nebst Betrachtungen eines Dritten, an intentional attempt to provoke Mendelssohn masquerading as a review of Johannes von Müller’s Reisen der Päpste.
January Jacobi arranges for a text—“Gedanken Verschiedener über eine merkwürdige Schrift” DM (1783.1): 3-9—attacking his pamphlet on Lessing to be published in Deutsches Museum. It includes comments from Dohm and Mendelssohn.
February Jacobi replies to the previous text anonymously in “Erinnerungen gegen die in den Januar des Museums eingerückte ‘Gedanken über eine merkwürdige Schrift’” DM (1783.1): 97-105.
25 March After visiting Mendelssohn in Berlin, Elise Reimarus informs Jacobi of Mendelssohn’s plans to extol Lessing.
April Mendelssohn publishes Jerusalem, oder über religiöse Macht und Judentum.
21 July Jacobi writes to Elise Reimarus and reveals Lessing’s supposed Spinozism
4 August Elise Reimarus forwards Jacobi’s letter to Mendelssohn.
16 August Mendelssohn replies to Elise Reimarus with skepticism.
1 September Elise Reimarus informs Jacobi of Mendelssohn’s reaction.
Fall While in Weimar, Jacobi reveals Lessing’s Spinozism to Goethe, Wizenmann, and Herder.
4 November Jacobi writes long letter to Mendelssohn with the full tale of his conversations with Lessing.
14 November Elise Reimarus informs Jacobi of her brother’s reaction to the revelation of Lessing’s Spinozism.
18 November Mendelssohn appears to concede the plausibility of Jacobi’s report.
22 November Jacobi forwards to Herder a copy of his letter to Mendelssohn.
5 December Elise Reimarus informs Jacobi that Mendelssohn is sick and will require more time to issue his response
24 December Elise Reimarus writes to Mendelssohn concerning Jacobi’s reaction to Mendelssohn’s concession.
Publication of Lessing’s Theologischer Nachlaß, which contain texts written over the course of Lessing’s life that show Lessing’s affinity toward Spinozism.
6 February Herder writes to Jacobi in order to express his agreement with the Spinozistic sentiment embodied in Lessing’s statement on Gleim’s wall.
4 July Elise Reimarus reveals to Jacobi that Mendelssohn had informed her of his plans to write something on Spinoza in a letter most likely written in April.
1 August Mendelssohn writes to Jacobi directly with his objections to Jacobi’s story.
5 September Jacobi promises Mendelssohn a detailed reply after he recovers from an illness.
21 April Jacobi sends Mendelssohn a letter explaining his understanding of Spinoza.
24 April Jacobi forwards the letter to Herder.
29 April Mendelssohn informs Elise Reimarus of his decision to publish his book on Spinoza without waiting for or consulting Jacobi further.
24 May Mendelssohn complains to Elise Reimarus about Jacobi’s method of conducting the dispute so far.
6 June Herder criticizes Jacobi’s tone in his letter to Mendelssohn.
9 June Goethe criticizes Jacobi’s metaphysics in a letter to Herder. Goethe also proclaims his agreement regarding Spinozism with Lessing and Herder.
21 July Mendelssohn purposely informs Jacobi belatedly of his decision to publish his book on Spinoza.
Early September Jacobi publishes Über die Lehre des Spinoza in Briefen an den Herrn Moses Mendelssohn, which he wrote in one month.
2 September Jacobi sends Herder a copy of his books.
30 September Jacobi sends Mendelssohn a copy of his book.
Early October Publication of Mendelssohn’s Morgenstunden: oder, Vorlesungen über das Daseyn Gottes.
4 October Mendelssohn sends Jacobi a copy of his book.
16 October Mendelssohn complains to Kant about the quality of Jacobi’s book and attempts to enlist Kant’s support for his side.
24 October Elise Reimarus criticizes Jacobi for besmirching Lessing’s reputation.
October/November Mendelssohn hastily composes his final reply to Jacobi.
5 November Hamann informs Jacobi of recent developments in Königsberg regarding the dispute..
7 November Jacobi writes to Elise Reimarus that he did not intend to slander Lessing.
31 December Mendelssohn becomes sick after racing to deliver his manuscript to his publisher.
4 January Death of Mendelssohn
January Posthumous publication of Mendelssohn’s An die Freunde Lessings: Ein Anhang zu Herrn Jacobis Briefwechsel über die Lehre des Spinoza.
7 January Nicolai dismisses Jacobi’s public intervention in his encomium to Mendelssohn.
January/February Debate over responsibility for Mendelssohn’s untimely death after Karl Philipp Moritz criticizes Jacobi’s conduct in the dispute.
February Matthias Claudius defends Jacobi in “Zwei Rezensionen etc. in Sachen der Herren Lessing, M. Mendelssohn, und Jacobi.”
April Jacobi publishes Wider Mendelssohns Beschuldigungen betreffend die Briefe über die Lehre des Spinoza. Wizenmann publishes Die Resultate der Jacobischen und Mendelssohnschen Philosophie: kritisch untersucht von einem Freywilligen.
5 May Goethe further elaborates his thoughts on metaphysics in a letter to Herder.
4 August Kant criticizes Mendelssohn’s rationalism in a note to a review of Mendelssohn’s Morgenstunden.
Fall Reinhold begins the serial publication in Der teutsche Merkur of his Briefe über die kantische Philosophie TM (1786.3): , which connects Kant’s philosophy with the debate over Spinoza.
October Kant publishes “Was heißt: sich im Denken orientieren?” in the Berlinische Monatsschrift BM (1786.2): 304-29.
November Johann Heinrich Schulz publishes Der entlarvte Moses Mendelsohn oder völlige Aufklärung des rätselhaften Todverdrusses des M. Mendelsohn über die Bekanntmachung des Lessingschen Atheismus von Jacobi.
Spring August Wilhelm Rehberg publishes Über das Verhältnis der Metaphysik zu der Religion, in which he agrees that metaphysics leads to atheism. Johann Albert Heinrich Reimarus publishes Über die Gründe der menschlichen Erkenntniß und der natürlichen Religion in support of Mendelssohn’s position.
May Herder publishes Gott, einige Gespräche and sends a copy to Jacobi.
June Second edition of Kant’s Kritik der reinen Vernunft
For the preparation of this chronology, I am indebted to the work of Gerard Vallée’s introduction to his English language edition of The Spinoza Conversations between Lessing and Jacobi, Frederick Beiser in The Fate of Reason, and Pierre-Henri Tavoillort, Le Crépuscule des Lumières: Les Documents de la “querelle du pantheisme”(1780-1789). (Paris: Les Éditions du Cerf, 1995).