The Martyr of Reason
Moses Mendelssohn: Sage of Modernity
by Shmuel Feiner, translated by Anthony Berris
Yale University Press, 248 pp., $25
Faith and Freedom: Moses Mendelssohn's Theological-Political Thought
by Michah Gottlieb
Oxford University Press, 224 pp., $55
On Saturday evening, December 31, 1785, the eminent Enlightenment philosopher Moses Mendelssohn left his house to deliver a manuscript. He had finished it on Friday afternoon but, as an observant Jew, Mendelssohn waited until the Sabbath concluded to bring it to his publisher. So, at nightfall, he rushed out into the cold Berlin air without waiting for a carriage or stopping to put on a coat, though his wife Fromet begged him to do so. The manuscript he held was entitled To Lessing's Friends, and it was a pained yet characteristically elegant response to a critic named Friedrich Heinrich Jacobi.
Mendelssohn himself was the most famous of Gotthold Ephraim Lessing's friends, since their close relationship was widely taken to symbolize the religious tolerance and social possibilities of the German Enlightenment. Lessing had died in 1781, and Mendelssohn had intended to write a biography or memoir of his friend. But before he could do so, Jacobi had written to him with a shocking revelation: A few months before he had died, the great Enlightenment dramatist, critic, and man of letters had confessed to him that he knew no philosophy to be true but Spinoza's hen kai pan ("all is one"). This was, if true, scandalous. The "accursed Spinoza" was still an anathema in the 18th century. His denial of a transcendent deity and his teaching of the unity of God and the world (Deus sive Natura) was held to be the philosophical expression of a thoroughgoing atheism. For Jacobi, Lessing's Spinozism showed that the moderate Enlightenment endorsed by Mendelssohn and his circle was philosophically superficial and both politically and theologically dangerous. When carefully thought through, the rational religion of Mendelssohn, Jacobi alleged, collapses into nihilism (a term that Jacobi himself coined).
Mendelssohn and Jacobi corresponded with increasing heat and then in 1785—in what Mendelssohn regarded as an unforgivable breach of etiquette—Jacobi published their exchange with his own commentary under the title Concerning the Doctrine of Spinoza in Letters to Mr. Moses Mendelssohn. With the public disclosure of Lessing's confession, Jacobi launched what has come to be known as the Pantheismusstreit (the Pantheism Controversy). On the face of it, what Jacobi had initiated was a quarrel over the intelligibility and desirability of the moderate Enlightenment. Yet Mendelssohn understood that Jacobi's challenge was not just directed at his circle's intellectual project but also at what their confidence in reason and rational theism endorsed—religious toleration and increased sociability between Christians and Jews. Mendelssohn perceived in Jacobi's challenge a not-so-hidden agenda—it was yet another attempt to push him into the bosom of Christianity. By publicly exposing Lessing's professed "Spinozism," Jacobi was, in truth, undertaking an assault upon Mendelssohn's "Judaism."