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Enlightenment, Philosophy of


The enlightenment is a name popularly used to describe the extraordinary scientific, philosophical, religious, and political developments of 18th-century Europe. Like all historical periods, the Enlightenment had no abrupt beginning or end, and the determination of its temporal limits is considerably arbitrary. And like most popular historical nomenclature, the term used to describe this period, while setting in relief a very real aspect of the times, connotes an over simple and somewhat uncritical view of what actually occurred. The purpose of this article is to outline the philosophical thought that characterized the period; this may be conveniently done in two parts, the first discussing the French and English Enlightenment and the second the German Enlightenment.

French and English Enlightenment

It is undeniable that the scientific developments of 18th-century Europe prompted the wide dissemination of a new spirit, one opposed to a priori solutions and very much given to experimentation. Although the 18th century did not produce any scientific discoveries equaling in importance those of Galileo and Newton, it was a century during which an unusually large number of people began

to build on the scientific foundations already provided. The "scientific method" began to assume preeminence over all other approaches to important problems, even in moral and religious spheres; and scientific societies, journals, and encyclopedias multiplied their influence as means whereby scientists could exchange information and assist one another in their experimentation. The scientific laboratory became so popular, in fact, that it sometimes assumed the role of a status symbol among the socially elite, particularly in France, and accounts of laboratory experiments became more fashionable in some famous salons than court gossip. Moreover, at this time, in Europe's great universities chairs were founded in such sciences as anatomy, astronomy, botany, and chemistry.

Scientific Progress. Such scientific ferment produced a remarkably large number of concrete results. C. Linnaeus in his Systema naturae (Leiden 1735) provided a firm foundation for the complex task of classifying the large number of minerals, plants, and animals that had been discovered and described by him or his assistants, who made voyages to the most distant parts of the earth for this purpose. Also in the field of biology, George Louis Leclerc de Buffon published his Histoire naturelle, générale et particulière (44 v. Paris 17491804), which argued from the stratification of rocks and the occurrence of fossils at various levels that the planet was of a much greater age than that commonly inferred from Biblical accounts. B. de Maillet (16561738) also wrote the very popular Telliamed (Amsterdam 1748), in which he proposed the theory that terrestrial forms of life had evolved over long periods of time from aquatic forms. J. B. Lamarck rounded out the century by publishing his Philosophie zoölogique (Paris 1809), in which he added to the developing evolutionary theory the notion that evolution was a consequence of adaptation to environment.

Physical Science. In the fields of chemistry and physics, Sir Henry Cavendish (17311810) pioneered in experiments with gases, electricity, and heat. He demonstrated the compound nature of water, invented the eudiometer tube, and introduced the use of drying agents in experimentation. Joseph Priestley published a History of Electricity (London 1767) and, in the following decade, Experiments and Observations on Different Kinds of Air (6 v. London 177486). He discovered oxygen, demonstrated the similarity of respiration and combustion, and invented the "pneumatic trough" for collecting gases. Priestley was something of a philosophe too, writing a History of the Corruptions of Christianity (Northumberland, Pa. 1796) and lending his support to the American and French revolutions. A. L. Lavoisier, author of a Traité élémentaire de chimie (Paris 1789) and famous for his phlogiston theory of combustion, was also a pioneer in laboratory work and invented, along with P.S. Laplace, a device for measuring linear and cubical expansion due to heat. Laplace is more noted for the "nebular hypothesis," which he proposed in his Exposition du système du monde (Paris 1796), and for his pioneering work in probability theory.

The 18th century saw also extraordinary developments in the study of electricity. Benjamin Franklin (170690) published his Experiments and Observations on Electricity (3 v., London 175462). L. Galvani discovered what is now known as the galvanic principle; A. Volta produced the first electrical battery; and at the close of the century A. M. Ampère explained the attraction and repulsion of electrical currents.

Technology. Concurrent with these contributions to physical science, the spirit of the Enlightenment was also producing practical results. Edward Jenner (17491823) introduced the practice of vaccination in England; James Watt (17361819) developed a steam engine that was such an improvement over the older piston engine of Thomas Newcomen that it could be used to drive all sorts of machinery. And the textile industry was not slow to provide the machines. John Kay had invented the flyshuttle in 1733; James Hargreaves produced the "spinning jenny" in 1764; and Edmund Cartwright developed the power loom in 1785. Finally, Eli Whitney devised his cotton gin in 1793.

Theories of Man. Such successes in science and its applications gave thinkers of the Enlightenment great confidence in human progress. All one needed to make real the Utopias of which others had dreamed was to apply, to the direction of human life, the scientific method that had so successfully dealt with the physical world. It became the fashion to regard man as a very complex machine whose workings, once understood, could be controlled to produce whatever results might be desired. Three of the encyclopedists were particularly active in providing the new psychological theories: É. B. de condillac, J. O. de La Mettrie, and P. H. D. holbach. Abbé Condillac, in his Traité des sensations (Paris 1754), pushed John Locke's empiricism to the point of maintaining, against the Englishman's theory of "ideas of reflection," that all knowledge is ultimately sensation in one form or another. While Condillac himself was not a materialist in his conception of man, his work was a step in that direction. La Mettrie took the final step in his L'Homme machine (Leiden 1748), which was a completely mechanistic analysis of man's psychic activities; thinking, feeling, willing were all proclaimed to be physical functions of a highly complex, completely material mechanism whose motive power was self-love (see materialism).

Holbach, in his Système de la nature, ou des lois du monde physique et du monde moral (London 1770), helped popularize La Mettrie's view and emphasized the application of mechanism to the realm of morality. Man, Holbach said, is a purely physical being, and ethics is only a matter of considering this physical being from a certain point of view. "In all he does, a reasonable being ought always set before himself his own happiness and that of his fellows." And a consideration of l'homme machine from the ethical point of view revealed that "the source of man's unhappiness is his ignorance of nature." Such a conviction made possible a great optimism concerning man's perfectibility. M. J. A. C. condorcet gave expression to this optimism in his Esquisse d'un tableau historique des progrès de l'esprit humain (Paris 1794), a work that was written, ironically, while Condorcet was in hiding from the Jacobins.

Attitude Toward Religion. Another consequence of the 18th century's confidence in scientific method was an extremely critical attitude toward matters of faith matters that, by their very nature, could not be subjected to a "scientific" critique. Though I. Kant was busy in Germany attempting to provide some rational justification for faith, the general trend of the period was represented by the religious skepticism of the philosophes,

particularly Voltaire, J. D'Alembert, and D. Diderot. While these men attacked religion with a vehemence and lack of restraint that induce doubts about their good faith, it must be noted to their credit that much of what they attacked in the religious practices of their day was deserving of criticism, e.g., an excessive love for the miraculous and the bizarre, the Jansenistic view of God as a harsh and exacting master, the bitter rivalries between religious groups, the sentimentalities of some society women who played at being "spiritual," and the failure of powerful and wealthy believers to care for the poor and oppressed. To this extent the philosophes can be said to have worked for an "enlightenment" in religion and an end to superstition. However, failing to distinguish between genuine religion and its aberrations, they let their enthusiasm for scientific method lead them to characterize all religion based on revelation as superstition. Indeed, when mention is made of the Enlightenment in the 21st century, the characteristic most remembered is the replacement of religious faith by reasonwith reason being restricted, in theory if not always in practice, to what was empirically verifiable.

Political Notions. Parallel with the rejection of religious tradition there occurred a similar rejection of political traditions. The general acceptance of hereditary monarchical rule, a privileged class of nobles, and an alliance between the Church and the State gave way, by the end of the century, to the secularized liberty, equality, and fraternity of the French Revolution. The new spirit was epitomized in the 1789 Declaration of the Rights of Man and of the Citizen, which asserted that man had a natural right to liberty, property, security, and resistance to oppression; that sovereignty resided in the nation as a whole rather than in one man; that law was the expression of the general will of the people; and that all citizens were equal before the law. These same principles had guided the American Founding Fathers in severing the ties with monarchical England and in setting up a representative government, principles that had been popularized by Enlightenment writers such as Baron de montesquieu and J. J. rousseau. Thomas Jefferson and Benjamin Franklin were deeply imbued with the spirit of the Enlightenment; and Thomas paine was active in promoting this spirit, first in America in his Common Sense (Philadelphia 1776), afterward in England in his Rights of Man (Philadelphia 179192), and then in France, where he was elected to the Convention by the Department of Calais. Paine's The Age of Reason (London 179496) was an expression of the deism that became the religion of the Enlightenment.

Bibliography: c. l. becker, The Heavenly City of the Eighteenth-Century Philosophers (New Haven 1932). r. rockwood, Carl Becker's Heavenly City Revisited (Ithaca, N.Y. 1958). l. i. bredvold, The Brave New World of the Enlightenment (Ann Arbor 1961). e. cassirer, The Philosophy of the Enlightenment, tr. c. a. koelln and j. p. pettegrove (Princeton 1951). h. g. nicolson, The Age of Reason (Garden City, N.Y. 1961). g. havens, The Age of Ideas: From Reaction to Revolution in 18th-Century France (New York 1955). p. hazard, European Thought in the Eighteenth Century: From Montesquieu to Lessing, tr. j. l. may (New Haven 1954). c. frankel, The Faith of Reason: The Idea of Progress in the French Enlightenment (New York 1948). a. vartanian, Diderot and Descartes: A Study of Scientific Naturalism in the Enlightenment (Princeton 1953). r. r. palmer, Catholics and Unbelievers in 18th-Century France (Princeton 1939).

[r. z. lauer]

German Enlightenment

The German Enlightenment presents a rather complex intellectual structure in which various currents of thought are discernible ranging all the way from rationalism to pietism. This part of the article considers its historical development and concludes with a brief critique.

Historical Development. The history of the German Enlightenment may best be divided into three phases: the early period, that of Wolff and his school, and that of its full development.

Early Period (16901720 ). The central figure of this period is Christian Thomasius, with whom the first influence of English empiricism and psychologism began to be discernible in German philosophy. In place of the concept of man proposed by traditional metaphysics and moral philosophy, he substituted the notion of man as he actually is, and this particularly in his philosophy of law. Although Thomasius's teacher, Samuel Pufendorff (163294) still conceived law as a metaphysical and moral order, for Thomasius law was only a clever balancing of the instinctual and emotional life of man for its purely utilitarian value. Thomasius introduced the separation between law and ethics that was later to prove disastrous.

Wolff and His School (172050 ). Christian wolff was a typical rationalista term used in a pejorative sense by his opponents, particularly the Pietists and orthodox Protestants. Since Martin Luther had placed faith over reason, Pietism treated any religion based on reason as an encroachment upon the freedom and omnipotence of God and of His grace. Understanding and reason thereupon came to be the passwords of Wolff and of his school: through enlightened reason man was to be led to virtue and to happiness. The titles of Wolff's works repeatedly read Vernünftige Gedanken über . Actually, however, Wolff's emphasis on reason was not so much the usual rationalist emphasis as it was a return to the type of thought that characterized the school metaphysics of the 17th century and of G. W. leibniz in particular. Both Leibniz and Wolff were seeking a synthesis of reason and religion, of metaphysics and theology.

Nonetheless, Wolff's Pietistic opponents accused him of being atheistic. In 1723 he was relieved of his position in Halle, where he was professor of philosophy, and he was expelled from the region under threat of being hanged for his teaching. The Hessian University of Marburg received him, however, and there Wolff lived to see his renown reach its climax. In 1740 Frederick II of Prussia brought him back to Halle with full honors. The accusation of atheism was there seen to be completely unjust. Quite the opposite, Wolff had much occupied himself with proofs for the existence of God just as had the proponents of the older metaphysics. The treatment by Wolff, however, was not made in the spirit of the old metaphysics, but rather with a type of purely conceptual analysis that proved too little because it set out to prove too much. More particularly, Wolff understood proof (demonstratio ) in a mathematical sense, overlooking both experience and the inner life of man in the process, and therefore supplying judgments that were analytical and not synthetic.

Wolff's efforts later provoked Kant's criticism of the proofs for the existence of God. When Kant spoke of metaphysics, he usually had in mind the metaphysics of the Leibniz-Wolffian school. For his lectures on metaphysics, in fact, Kant had used a textbook of a student of Wolff, A. G. Baumgarten (171462), who is noted also for his work on aesthetics. Other students of Wolff include J. C. Gottsched (170066), who was similarly occupied with aesthetics; M. Knutzen (171351), who taught the young Kant in Königsberg; and G. B. Bilfinger (16931750), whose Philosophische Erleuchtungen served for a long time as the best textbook of Wolffian metaphysics. In 1737 there were already no less than 107 authors who were writing in a way that identified them as belonging to the Wolffian school. Opponents of Wolff included J. Lange (16701744), who was later professor of theology in Halle, as well as A. Rüdiger (16731731) and C. A. Crusius (171575).

Full Development (c. 175080 ). In the last phase, the German Enlightenment again fell under the influence of the French and English Enlightenment. Frederick II of Prussia, himself a freethinking litterateur, sent for C. A. Helvetius (171571) at Potsdam, made friends with Voltaire, and took Rousseau into his service. Other influences, traceable to John Toland (16701722) and Matthew Tindal (16561733), encouraged the growth of deism. Toland had been in Hanover in 1701 and 1702, while Tindal's work Christianity as Old as Creation (London 1730) was translated into German in 1741. In rationalist and Deist circles, the Hamburg Orientalist H.S. Reimarus (16941768) criticized the Bible and revelation in his unpublished Schutzschrift für die vernünftigen Verehrer Gottes. For him, miracles and revelation are unworthy of God. The thought of Moses Mendelssohn (172986) was also Deist.

The greatest figure in this last phase of the German Enlightenment, however, was Mendelssohn's friend G.E. lessing, the son of a Lutheran pastor in Saxony, a free-lance writer, poet (Minna von Barnhelm, Emilia Galotti, and Nathan der Weise ), secretary of famous personalities, dramatic producer of the Hamburg National Theater, and finally librarian at Wolfenbüttel. His poetry created a new literary taste, while his writings on aesthetics (Laokoon and Hamburger Dramaturgie ) provide a theory of art, especially of drama, that to this day has not become dated. In his Wolfenbüttler Fragmenten Lessing published a part of Reimarus's Schutzschrift and thereupon provoked a passionate discussion over whether religion should be based on reason or on revelation. Lessing's philosophy saw the divine in the rational ordering of the universe, the moral in reason itself, and the education of the human race in religion and the great religious figures. For him, the religions are not something conclusive, but stages in the vital development of mankind. Everything is undergoing evolution, including religion itself. In particular, there is no final truth for man, but only the constant search for it; this alone gives meaning to the term truth. So as not to shorten this constant search, Lessing taught a repeated existence for man, a palingenesis similar to that of the transmigration of souls. His Erziehung des Menschengeschlechtes (Berlin 1780), moreover, contains a philosophy of history and of religion that exerted as much influence on German idealism as it did on liberal Protestant theology of the 19th century.

Alongside the unique and great figure of Lessing stand a long line of popular philosophers of this period, such as the psychologist J. N. Tetens (17361807), the moral philosopher J. G. Sulzer (172079), the spiritual aphorist G. C. Lichtenberg (174299), the Hamburg educator J. B. Basedow, and the still more important Swiss educator J. H. pestalozzi. The last-named, however, extends beyond the period of the Enlightenment, and the emotional element in his work takes on more significance than the rational. Those who eventually brought about the overthrow of the Enlightenment were J. G. hamann, F.H. jacobi, and J. G. herder.

Critique. The Enlightenment in Germany did much good for education in general and for public instruction in particular. Even catechetical instruction benefited from its lively stimulation, insofar as it replaced rote memory with understanding and encouraged independent thought similar to that of the Socratic method. The cultivation of the humanities and of intellectual tolerance was here served, just as was the battle against biased judgments.

On the other hand, the Enlightenment itself gave rise to new and dangerous prejudices. In this connection one could mention its faith in the omnipotence of reason and of science, its uncritical progressive thinking, and the naïveté of its humanism, which treated man as though he had suffered no blemish from original sin and could work out his own destiny. A similar excess lay in the Enlightenment's Deist conviction that man is able to discern what is possible for God and what is not. Revelation cannot contradict reason, this is true, but man's reason is not the complete and exclusive measure of revelation. The Enlightenment was just as uncomprehending in the face of mystery as it was in the face of history. The enlightened man was faced with the temptation to make himself the measure of all things because he conceived himself as the ideal man. For that reason he regarded parochial education as a second-class effort and thought that a Catholic could not be a complete scholar. One consequence of this attitude is secular education, which is not aware of its peculiar presuppositions and prejudices and to this extent encroaches upon true freedom. "Enlightened" thinkers seem unaware that there is no such thing as the ideal man whom they take themselves to be.

See Also: freethinkers; theism.

Bibliography: f. c. copleston, History of Philosophy (Westminster, Md. 1946) v.6, Wolff to Kant. h. leisegang, Lessings Weltanschauung (Leipzig 1931). h. thielicke, Offenbarung, Vernunft und Existenz: Studien zur Religionsphilosophie Lessings (Gütersloh 1936; 4th ed. 1959). m. campo, Cristiano Wolff e il razionalismo precritico, 2 v. (Milan 1939). m. wundt, Chr. Wolff und die deutsche Aufklärung (Stuttgart 1941); Die deutsche Schulphilo-sophie im Zeitalter der Aufklärung (Tübingen 1945). h. m. wolff, Die Weltanschauung der deutschen Aufklärung in geschichtlicher Entwicklung (Bern 1949). r. haass, Die geistige Haltung der katholischen Universitäten Deutschlands im 18. Jahrhundert: Ein Beitrag zur Geschichte der Aufklärung (Freiburg 1952). w. philipp, Das Werden der Aufklärung in theologie-geschichtlicher Sicht (Göttingen 1957).

[j. hirschberger]

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