Of the many writers of this period we may select as representative, Mendelssohn, Nicolai, and Lessing— Mendelssohn, the religious metaphysician; Nicolai, the literary exponent; Lessing, the cultured critic of "the Popular Philosophy."
Moses Mendelssohn, or Moses, as he frequently called himself, the son of a Jewish schoolmaster, was born in Dessau in 1729. As a boy he studied the Old Testament, which he learned by heart. He went at the age of fourteen to Berlin, where for many years he had a hard struggle for a livelihood. Ultimately he received the post of bookkeeper to a wealthy merchant, on whose death he became the head of the business. His life, however, was chiefly devoted to philosophical pursuits. All writers agree in ascribing to Mendelssohn a beautiful and attractive personality. In his simplicity and absence of care for the things of this life, in his philosophic calm and unselfish devotion to the good of man, as well as in his unquestioning trust in the Divine order of the world, he has been compared with Socrates and Spinoza. His writings bear the same character. His pen, says Zeller, was consecrated to the enlightenment of humanity. While he was interested in the larger questions of religion, he remained true to the faith of his fathers, and it was his special mission to deliver his co-religionists from the narrow prejudices and cruel disabilities under which they laboured. His principal works are: Letters on the Sensations (1755); Evidence in Metaphysics (1763); Phaedon (1767), a dialogue on the Immortality of the soul after the manner of Plato; Jerusalem (1783), a defence of Judaism; Morning Hours, essays in refutation of Pantheism.
In his philosophy he professes adherence to Leibnitz and Wolff, and in the more speculative part of his teaching he adopts their standpoint. But he was also influenced by a study of Locke and Shaftesbury. Metaphysics he calls his queen, but he regards the supreme purpose of speculative thought to further the blessedness of man. Nobility of life is the motive of all study, and the dictates of common sense are the test of truth.
The first question for Mendelssohn is, what are the conditions of human blessedness? To answer this question it is necessary to investigate our human nature. Hence in his Letters on the Sensations he examines the sources of our knowledge. These he finds to be desire, feeling, and reason—feeling or sensation being the intermediate or connecting-link between the faculties of desire and thought. Pleasure or pain is the direct object of sensation. In harmony with Leibnitz' distinction between dim and clear perceptions, he distinguishes between three kinds of sensation—sensual pleasure, the feeling for natural beauty, and the delight in moral perfection. He discards the Leibnitz-Wolffian view of a pre-established harmony in the relation of body and soul, and contents himself with a confession of ignorance.
While he deals with all manner of subjects, and especially with the Fine Arts, he is most deeply interested in moral and religious questions. In seeking for a criterion and motive for conduct, he says that that which is the ground instinct of our nature must be the highest law for our will; and as no rational being can dissociate himself from his fellowmen, virtue, justice, and love of our kind unite in forming the highest elements of blessedness. Every free being is bound by the inner laws of his nature to produce as much perfection, beauty, and order in the world as lie in his power. The highest maxim of the moral life, therefore, is—"Make thine own and thy neighbour's inner and outer state, in due proportions, as perfect as thou canst."
One of the most important questions which he feels impelled to discuss is the nature of our faith in the existence of God. He deals with the subject in his Evidence in Metaphysics. He is assured that certainty is as attainable in theology as in mathematics. He examines the various proofs for God's Being, and is an enthusiastic defender of the Ontological argument, and he clinches his position with a dilemma,—"Either God is impossible or He exists."
Though many of his admirers, including Kant, consider that his Jerusalem is his finest work, none was so popular as his Phaedon, in which he discusses the immortality of the soul, a theme of special interest among the writers of this time. Socrates is conjured up as a citizen of Berlin of the eighteenth century, and is made the champion of religious enlightenment. Mendelssohn maintains that the lot of all men will be a happy one after death. The soul must be eternal. Even nature knows nothing of annihilation. Things change, but do not pass into nothingness. The spirit cannot be less enduring than the body. The inconceivability of God having pre-destined men to misery, the impossibility of a being like man, whose end is obviously perfection, being mocked and frustrated in his aspirations; and, finally, the necessity for a state after death for the adjustment of the inequalities of this life— these are the arguments with which Mendelssohn seeks to establish the doctrine of the immortality of the soul.
There are few more impressive figures in the history of philosophy than that of Mendelssohn. He is not, indeed, a deep or original thinker. He cannot compare with a Leibnitz or a Kant. He is essentially an eclectic, culling his flowers from many fields. But he adds a grace both of language and thought to everything he touches. His character is even finer than his writings. He is one of the noblest representatives of a class of writers who have done much to humanize and broaden the general culture of the world. Such men are, indeed, indebted to the severer thinkers for their inspiration, but mankind often learns more from the popular teacher than the profound philosopher.
Frederick Nicolai (1733-1811), like his friend Mendelssohn, was largely self-taught, and, like him also, was engaged in trade. Apprenticed to a bookseller, he employed his leisure in acquiring English and Greek. He went to Berlin, where he entered upon what became his life-work—that of editor and publisher, which he pursued in the interests of the enlightenment. His greatest undertaking was a Universal German Library, which he edited for twenty-one years. All the best writers of the times were contributors to this work. Nicolai did much in this way to extend a knowledge of high-class literature and to elevate the thought and taste of his countrymen. As might be expected, the philosophy which he taught never took a very definite or systematic shape. His views are contained in a number of essays, reviews, criticisms, and letters to his friends Mendelssohn and Lessing. What he desires chiefly to inculcate is a "sound philosophy." He claims to be a man of business and not a scholar, who writes to help common people to take a practical and unprejudiced view of things. He avoids technical language, and aims at utility and general clearness of thought. His object is to enlighten men's minds so that by clearness of intellectual vision they may attain to true happiness. He wages a constant warfare against prejudice and tradition. His hero is Frederick the Great, whom he admires on account of his tolerance and sympathy with culture. He believes in making men good citizens, hence his watchword is the "public good," after which every man ought to strive, for only in the weal of others will he find his own blessedness. If he lacked the spirituality and idealism of Mendelssohn, and was inferior to Lessing in literary talent, he did perhaps not less than either for the promotion of knowledge and the education of the people. He embodied the spirit of the age. In his conceit, self-confidence, and shallow optimism he was at once a product and type of the Enlightenment.
Nicolai is, however, chiefly interesting as marking a transition from Mendelssohn to Lessing. He is less of a dogmatist and more of a critic than the former. Gifted in a small degree with the historical sense and with a tendency to a rationalistic view of the world, he may be regarded as preparing the way for those characteristics which made Lessing at once the last of the Illuminati and the first to expose their insufficiency.
The name of Lessing belongs to the history of Literature rather than to that of Philosophy. But he is one of those many-sided men whose influence has been exerted in nearly every realm of thought and life. In the literature of Germany he may be said to have created a new epoch and to have given an inspiration to those deeper feelings and aspirations which found expression in the Sturm und Drang period. If he is to be regarded as an apostle of the enlightenment, it is only in the sense that he gave to that tendency a broader and larger outlook. Just as Rousseau was the emancipator of French Illuminism, so Lessing was the liberator of those ideas of his countrymen which were yearning for expression. A new sense of the possibilities of life is awakened by him. He is the creator of new ideals, and by his return to classical sources as well as by his realization of historical development, he has given to the enlightenment a fuller and richer significance. He was at once a man of learning and a man of the world, and in him the various elements of the time unite. Religion and rationalism, literature and life, morality and aestheticism, toleration and intensity, individualism and universality, are strangely combined in this restless, strenuous spirit.
Lessing was a man of extraordinary ability and untiring energy. He was engaged in continual controversy. Freedom was his watchword, says one of his biographers, and his life was a series of battles for truth. We cannot enter here upon an account of his literary activities. Fables, essays, poems, dramas, art-criticisms, and theological treatises came forth in rapid succession from his restless brain.
His Dramaturgy, in which he dissociates himself from the artificial French tradition of the "three unities" and points to Shakespeare as his model, marks a turning-point in the history of the drama; while his Laokoon, which contains his philosophy of art, breaks fresh ground in the interpretation and relations of Sculpture, Painting, and Poetry. Of Minna von Barnhelm Goethe says, it opened up a new world in literature—a world of living men, while his Amelia Galotti awakens men to the deep tragic element in life. His Nathan der Weise embodies one of the leading aims of his life—his demand for tolerance and freedom of thought in religious matters. A Jew, a Mohammedan, and a Christian are brought together in the time of the crusades. The lesson of the spirit of Nathan the Jew is that a man's creed is of little moment provided there be the temper of charity and the spirit of true humanity. The principal thing is not whether we are Jews or Christians, but men.
It was perhaps the same desire for toleration and fairness which actuated him to publish the Wolfenbuttel Fragments, purporting to be a MS. of an unknown author found in the library of Hamburg, in which the credibility of the Gospels was attacked. The work was really by Reimarus, a friend of Lessing, but Lessing was regarded as the author, and was involved through its statements in bitter controversy. Probably he only endorsed its views in a modified degree. Christianity had roots in his life too deep to be shaken by such shallow criticism. But he was pleased with any attempt which demonstrated that the truth of the Gospel was independent of the Scriptures or any outward channels through which it happened to be conveyed to mankind.
Next to his demand for freedom of thought and truth for its own sake, and not for the happiness and peace it might bring, the most striking feature of his character was his Individualism. He held with his friends, that the real subject of philosophy is man; but it must be man in his ideal and perfect totality. The perfection of mankind is only possible through the perfection of individuals. States exist for men. Governments and churches, all political and ecclesiastical institutions are but necessary evils—moral safeguards and aids of order and religion. He will not allow that men should be influenced by patriotism, but that each should be a citizen of the world. It should be our ambition to free ourselves from all limitations of nationality, religion, and rank and be known simply as men.
His individualism is based upon the Leibnitz-Wolffian philosophy which he espoused in his early college days. His metaphysical views rest upon the Leibnitzian theory of Monads. Each individual is a separate entity, and each soul must work out its own inner life. At the same time, he perceives that the world is composed of infinite gradations of existences which together form a whole. Each soul is ever striving after perfection, and there is no reason, he thinks, why an individual may not be born into the world several times, and with each new life attain to a higher stage of existence. He follows Leibnitz also in his conception of Divine Purpose and Determination. All things are not merely related, but are progressing towards a higher end. He will not, however, yield to the easy optimism of the Enlightenment, which cannot believe that a good God would cause pain and misery. As against Mendelssohn, he defends the doctrine of eternal punishment. Heaven and Hell are not two states in time and place. They are not merely future localities, but the possible conditions of every life which our own actions create.
But Lessing is not a blind follower of Leibnitz, and in his later writings, especially in his work on the Reality of Things Outside of God, he approaches the pantheism of Spinoza. This tendency to combine different elements of thought reveals another characteristic of the man. His inclination is ever towards paradox and contrast. No sooner does he see one side clearly than the other side obtrudes itself and demands recognition. "The more anyone tries to prove to me the truth of Christianity, the more do I see its objections." It is this double movement of thought which accounts for his seeming contradictions, and rouses often the suspicion of his friends. Now he speaks with the voice of a Rationalist, and now of an orthodox Christian. "The Theologians," Nicolai writes to him, "believe that you have become a free-thinker, and the free-thinkers that you have become a Christian."
Lessing is not satisfied with an individualistic view of the world; he seeks, therefore, to combine Spinoza with Leibnitz. If the world presents a number of isolated existences, it also reveals a comprehensive unity. Of God we can form no other idea than the Being in whom all things consist, and who includes in Himself all variety and change. Though He is outside of all things, nothing is outside of Him. That which enters not into the notion of God has no existence. Out of this idea of God he endeavours to develop the Christian doctrine of the Trinity. The Father is revealed in the thought, the Son in the activity of God, while the Holy Spirit is the union of the revealing and the revealed, of the thinking and acting God.
Lessing was originally intended for the Church, and all his life he took a deep interest in theological questions. In his investigation of Christian truth he combines the rationalist with the man of faith. He is not satisfied with the formal orthodoxy of the Church, but he is as little pleased with the shallow rationalism of many of the Enlighteners, with their arid deism and utilitarian morals. The central point around which all his criticism of Christianity turns is the distinction between form and faith, the spirit and the letter. The proof of Christianity is not to be sought in manuscripts, dates, and Gospel harmonies. The religion in the Gospels is not the religion of Christ. No two men will be found to attach the same meaning to Christianity. Christ and not the Bible is the primary object of belief. Lessing believes in a religion of reason, which is older than the Scriptures. Religion is not true because the apostles taught it, but they taught it because it is true. Truth is not a thing once and for all given us through a book. It is a process, a development. God is revealing Himself in history, and is educating the race by the gradual unfolding of His thoughts through life. This is the theme which he sets forth in his work on the Education of the Human Race. He sees a gradual evolution going on in the world from lower to higher forms of faith. Christianity, as the religion of a more fully developed humanity, succeeds Judaism, just as Judaism succeeded the natural religions of early times. Revelation is to the entire race what education is to the individual. God leads man on by earthly hopes and material promises to more spiritual things. The time will come when the Christian will be able to dispense with all notions of heavenly reward, and will do right because it is right. At present we are under the dispensation of the Son, just as a former age was under the dispensation of the Father. But Lessing believes there will be a third and higher dispensation,—the kingdom of the Spirit,—in which men shall no longer obey God through fear or for the sake of recompense, but because goodness is its own reward. This ideal state will be reached when the reign of reason is supreme.
In this view of the future, it will be seen, Lessing passes beyond the standpoint of the Enlightenment, and has given expression to an idea of historical development which has proved most fruitful in later philosophy. We can recognise the child of the Enlightenment in his demand for a freer and more reasonable faith, emancipated from forms and traditions. He is at one with the age in his desire to extricate morality from dogma, and life from belief. But this morality and life for which Lessing pled, involve sterner demands than the representatives of the Enlightenment dreamt of. He rigidly excludes all utilitarian motives and eudaemonistic incentives. He will know nothing of happiness and felicity as ends. He has no doubt about the Immortality of the soul, but he will not say that virtue and goodness in this life should be based on our hopes for the next. The goal of humanity will be reached, the true Enlightenment attained, when the hearts of men are so purged and purified that virtue will be loved and sought for itself alone.