Moses Mendelssohn

Mendelssohn, Moses (1729–86)

A Jewish disciple of Leibniz and Wolff, Mendelssohn strove throughout his life to uphold and strengthen their rationalist metaphysics while sustaining his ancestral religion. His most important philosophic task, as he saw it, was to refine and render more persuasive the philosophical proofs for the existence of God, providence and immortality. His major divergence from Leibniz was in stressing that ‘the best of all possible worlds’, which God had created, was in fact more hospitable to human beings than Leibniz had supposed. Towards the end of his life, the irrationalism of Jacobi and the critical philosophy of Kant shook Mendelssohn’s faith in the demonstrability of the fundamental metaphysical precepts, but not his confidence in their truth. They would have to be sustained by ‘common sense’, he reasoned, until future philosophers succeeded in restoring metaphysics to its former glory. While accepting Wolff’s teleological understanding of human nature and natural law, Mendelssohn placed far greater value on human freedom and outlined a political philosophy that protected liberty of conscience. His philosophic defence of his own religion stressed that Judaism is not a ‘revealed religion’ demanding acceptance of particular dogmas but a ‘revealed legislation’ requiring the performance of particular actions. The object of this divine and still valid legislation, he suggested, was often to counteract forces that might otherwise subvert the natural religion entrusted to us by reason. To resolve the tension between his own political liberalism and the Bible’s endorsement of religious coercion, Mendelssohn argued that contemporary Judaism, at any rate, no longer acknowledges any person’s authority to compel others to perform religious acts.

1 Metaphysics/natural theology

Affectionately called ‘the German Socrates’ by European admirers, and hailed by some of his Jewish disciples as a modern Maimonides, Moses Mendelssohn (born Dessau, died Berlin), despite his hunchback, cut a towering figure in his generation. Emerging from the ghetto with a solid command of traditional Jewish learning and a wide knowledge of medieval Jewish philosophy, he independently learned ancient and modern European languages, literature and philosophy. In an astonishingly short time he became an important cultural critic and went on to produce notable contributions to German philosophy, especially in metaphysics, ethics and political theory. Unlike Spinoza, the only prior Jewish thinker of modern times to have had a major impact on European thought, Mendelssohn retained his affiliation with Judaism. He actively promoted and fostered modernization within the Jewish community and spoke out forcefully and effectively in governmental and intellectual fora for the bestowal of equal civil rights on Jews. Challenged by adversaries and well-intentioned ‘friends’ to explain his seemingly unjustifiable loyalty to an outmoded religion, Mendelssohn wrote some of the seminal works of modern Jewish philosophy.

Mendelssohn made almost no claim to originality in metaphysics. He described himself as little more than an exponent of the teachings of the Leibniz/Wolffian school, perhaps lending a more felicitous or up-to-date expression to the affirmations of God’s existence and providence and human immortality that had been propounded by Leibniz and Wolff and their disciples. Here and there, however, he admitted modestly that he was providing a new version of an old argument or even saying something that had not been said before.

Mendelssohn made his reputation and set out his basic metaphysical stance in his Abhandlung über die Evidenz in metaphysischen Wissenschaften (Treatise on Evidence in Metaphysical Knowledge), an essay that took first prize in a competition sponsored by the Royal Academy in Berlin in 1763; Immanuel Kant received an honourable mention. The Academy’s question was whether ‘the truths of metaphysics in general, and the first principles of natural theology and morality in particular’ can be shown to be as securely established as those of mathematics. Mendelssohn answered that such principles ‘are capable of the same certainty’ but are by no means as easily grasped. After discussing the obstacles to such comprehension, he went on to offer cosmological and ontological proofs for the existence of God. He sought to give the ontological argument an ‘easier turn’ by reversing its usual course and arguing first for the impossibility of God’s nonexistence and then against the notion that the most perfect being would enjoy a merely possible existence.

Following Leibniz, Mendelssohn argued in a number of writings that the combination of divine goodness and greatness known as providence brings into being ‘the best of all possible worlds’. He was certainly aware of the abundance of evil and injustice in the world. But he found that the good outweighed the evil, and indeed that the quantity of evil was less than Leibniz himself had supposed. For Mendelssohn joined with other, later representatives of the Aufklärung in rejecting the Christian dogma, accepted by Leibniz, that most human beings are destined for eternal damnation. This idea, so much at odds with Leibniz’s recognition that the perfection and happiness of rational creatures are critical in God’s design, was, he wrote, a notion of which ‘neither our reason nor our religion knows anything’ (see Providence; Evil, problem of).

What reason teaches about the afterlife is, according to Mendelssohn, altogether consolatory. This view emerges most clearly in what was probably his most famous work, a philosophical dialogue entitled Phädon, oder über die Unsterblichkeit der Seele (Phaedo, or on the Immortality of the Soul) (1767). Borrowing from Plato the title and the setting, in Socrates’ jail cell, Mendelssohn used the condemned philosopher as the mouthpiece for an argument he had admittedly derived from his own recent predecessors, including such Aufklärer as the natural theologian Hermann Samuel Reimarus and the liberal Protestant theologian Johann Joachim Spalding. ‘Is it consistent’, Mendelssohn’s Socrates asks, ‘with the Supreme Wisdom to produce a world in order to make the happiness of the creatures inhabiting it arise from the contemplation of its wonders and a moment later deprive them of the capacity for contemplation and happiness?’ Pursuing the idea of divine goodness to its logical conclusion, Mendelssohn reasoned that the afterlife must be the arena in which the world’s injustices are rectified and all rational creatures continue to progress towards ever higher perfection and happiness.

Going beyond his rhetorical question and other arguments of similar provenance, Mendelssohn proudly offered what he saw as an original argument for immortality, a ‘proof from the harmony of our duties and rights’: An individual who believed that death marked the end of his existence would find that his natural right to preserve his own life at all costs would conflict at times with the state’s demand that he be prepared to lay down his life for the common good. But such a conflict can have no objective warrant. For in the mind of God, ‘all the duties and rights of a moral entity are in the most perfect harmony’. Since the state’s right to call for the supreme sacrifice is irrefutable, it is evident, Mendelssohn concludes, that the human soul does not die with the body.

In time Mendelssohn himself came to see weaknesses at many points in the philosophical structure he had upheld. Confronted, toward the end of his life, by the irrationalism of F.H. Jacobi and by the new critical philosophy of Immanuel Kant, whom he called the ‘all-crusher’, he felt compelled to acknowledge the insufficiency of rationalistic metaphysics. In his fullest exposition of the philosophy he had set forth, Morgenstunden, oder Vorlesungen über das Dasein Gottes (Morning Hours, or Lectures on the Existence of God) (1785), he sorrowfully ceased to reaffirm its irrefutable truth.

Yet, whatever speculative reason might seem to teach, he now argued, common sense still sufficed to orient people and guide them along the path to the most important truths. Just what Mendelssohn meant by common sense has been a subject of much dispute, both among his contemporaries such as Thomas Wizenmann and Kant himself and among modern scholars. But, however he conceived of this faculty, it is clear that he expected our reliance on it to be temporary. For, in the ‘cyclical course of things’, providence would cause new thinkers to arise who would restore metaphysics to its former glory.

2 Moral and political philosophy

Following Wolff, Mendelssohn affirmed that the fundamental moral imperative is a natural law obliging all rational beings to promote their own perfection and that of others. Unlike Wolff, he did not elaborate all the ramifications of this natural law. But he clearly saw perfection in much the same terms as Wolff, as an unending process of physical, moral and intellectual development, leading naturally to the increase of human happiness.

In sharp contrast to Wolff, Mendelssohn regarded liberty as an indispensable precondition of the pursuit of moral and intellectual perfection. Only a free person, he argued, can achieve moral perfection. For virtue is the result of struggle, self-overcoming and sacrifice, and these must be freely chosen. Intellectual perfection, too, can be attained only by one who is free to err. So, in place of Wolff’s tutelary state, Mendelssohn developed a contractarian polity that left individuals largely free to define their own goals. Insisting above all on the inalienable liberty of conscience, he decried any state attempt to impose specific religious behaviour or to discriminate against members of a minority faith. While Mendelssohn’s liberalism clearly flowed from his commitment to liberty itself, it was no doubt also informed by his concern for the situation of his fellow Jews, whom he ardently wished to see relieved of a degraded political and social status.

3 Philosophy of Judaism

Mendelssohn faced fewer difficulties in reconciling his Leibniz-Wolffian views with his Judaism than his mentors or their disciples had confronted in reconciling their philosophical views with Christianity. Because he saw little conflict between philosophy and Judaism and because his own position as the first Jew to be accepted by the intellectuals in a fundamentally intolerant society was precarious, he initially refrained from explaining to the general public his continued adherence to his ancestral religion. But he was by no means oblivious to the challenges that Enlightenment scepticism posed to all believers in revealed religions. Nor was he immune to attack. In response to repeated demands from critics that he account for his irrational adherence to Judaism, he wrote his celebrated treatise Jerusalem (1783). Subtitled Über religiöse Macht und Judentum (On Religious Power and Judaism), Jerusalem responds to August Friedrich Cranz’s charge that the religious coercion of recalcitrant Jews countenanced in Judaism is blatantly incompatible with Mendelssohn’s own political liberalism. In responding to this charge, Mendelssohn proceeded beyond the call of his immediate duty and outlined a general philosophy of Judaism.

Viewed against the backdrop of medieval Jewish philosophy, Mendelssohn’s account contains both familiar and unfamiliar elements. Following in the footsteps of Saadiah Gaon, Judah Halevi and Maimonides (and seemingly ignoring the criticisms of Spinoza and various sceptics) he maintained that God’s revelation at Sinai was an amply attested historical fact (see Saadiah Gaon; Halevi, Judah; Maimonides, M.). What God disclosed to the people of Israel, Mendelssohn held, was not a ‘revealed religion’ commanding the acceptance of particular dogmas but a ‘revealed legislation’ requiring the performance of particular actions. The Israelites at Sinai had already acquired, by unaided reason, a knowledge of the universal religion of humankind. What they learned from revelation was a set of God-given duties. Noting the broad range of these duties and the manifold aspects of life encompassed by them, Mendelssohn reflected at length on the so-called ‘ceremonial law’, problematized at least since the earliest days of the Christian critique of Judaism. This body of obligations, he reasoned, seems to be intended to combat idolatrous tendencies by ordaining actions that perpetually bring to mind the fundamental truths of natural religion. Observance of these divinely ordained regulations allowed Jews to maintain their grasp of true religion and so to serve as a salutary example to the other peoples of the earth (see Halakhah).

In keeping with the tenets of traditional Judaism, Mendelssohn insisted that the Bible’s revealed legislation remained in force perpetually, subject only to such modifications as the changes of time and circumstance rendered advisable. But he parted company with tradition in arguing that the Roman destruction of the Temple in Jerusalem had transformed Jewish law from a corpus of communally enforceable obligations into a code which only the individual Jew had the right to impose on himself or herself. This unprecedented claim parried the charge of illiberalism. Whether it represents a reluctant and merely tactical concession to liberalism, as some have argued, or whether it reflects Mendelssohn’s true convictions, as is more commonly believed, it was clearly the only means that Mendelssohn could find to render modern Judaism fully compatible with political liberalism.