To further their propaganda without at the same time attracting the notice of the civil authorities the rationalist party had recourse to various devices. Pamphlets and books were published, professedly descriptive of manners and customs in foreign countries, but directed in reality against civil and religious institutions in France. Typical examples of this class of literature were the /Persian Letters/ of Montesquieu, /A Description of the Island of Borneo/ by Fontanelle, /The Life of Mohammed/ by Henri de Bouillon Villiers, and a /Letter on the English/ from the pen of Voltaire. The greatest and most successful work undertaken by them for popularising their ideas was undoubtedly the /Encyclopedie/. The professed object of the work was to give in a concise and handy form the latest and best results of scholarship in every department of human knowledge, but the real aim of the founders was to spread their poisonous views amongst the people of France, and to win them from their allegiance to the Catholic Church. In order to escape persecution from the government and to conceal their real purposes many of the articles were written by clerics and laymen whose orthodoxy was above suspicion, and many of the articles referring to religion from the pen of the rationalistic collaborateurs were respectful in tone, though a careful reader could see that they did not represent the real views of the author.
Sometimes references were given to other articles of a very different kind, where probably opposite views were established by apparently sound arguments. The originator of the project was D'Alembert, who was assisted by Diderot, Voltaire, Montesquieu, Condillac, Buffon, and D'Holbach. The work was begun in 1750, and in spite of interruptions and temporary suppressions it was brought to a successful conclusion in 1772. The reviewers and the learned world hailed it with delight as a veritable treasure-house of information. New and cheap editions of it were brought out for the general public, and in a remarkably short time the influence of the Encyclopaedists had reached the lowest strata of French society. Many of those in authority in France favoured the designs of the Encyclopaedists, and threw all kinds of obstacles in the way of those who sought to uphold the teaching of the Church, but soon they had reason to regret their approval of a campaign that led directly to revolution.
(b) The Aufklarung Movement in Germany.
See bibliography (viii. a). Tholuck, /Abriss einer geschichte der Umwalzung seit 1750 auf dem Gebiete der Theologie in Deutschland/, 1839. Staudlin, /Geschichte des Rationalismus und Supranaturalismus/, 1826. Bruck, /Die rationalistischen Bestrebungen im Kath. Deutschland/, 1867. Weiner, /Geschichte der Kath. Theologie in Deutschland/, 1889. Wolfram, /Die Illuminantem in Bayern und ihre Verfolgung/, 1898-1900.
In Germany the religious formularies, composed with the object of securing even an appearance of unity or at least of preventing religious chaos, were not powerful enough to resist the anti-Christian Enlightenment that swept over Europe in the eighteenth century. At best these formularies were only the works of men who rejected the authority of the Church, and as works of men they could not be regarded as irreformable. With the progress of knowledge and the development of human society it was thought that they required revision to bring them more into harmony with the results of science and with the necessities of the age. The influence of the writings imported from England and France, backed as it was by the approval and example of Frederick II. of Prussia, could not fail to weaken dogmatic Christianity among the Lutherans of Germany. The philosophic teaching of Leibniz (1646-1710), who was himself a strong upholder of dogmatic Christianity and zealous for a reunion of Christendom, had a great effect on the whole religious thought of Germany during the eighteenth century. In his great work, /Theodicee/, written against Bayle to prove that there was no conflict between the kingdoms of nature and grace, greater stress was laid upon the natural than on the supernatural elements in Christianity. His disciples, advancing beyond the limits laid down by the master, prepared the way for the rise of theological rationalism.
One of the greatest of the disciples of Leibniz was Christian Wolf (1679-1754), who was not himself an opponent of supernatural religion.
The whole trend of his arguments, however, went to show that human reason was the sole judge of the truths of revelation, and that whatever was not in harmony with the verdict of reason must be eliminated. Many of his disciples like Remiarus, Mendelssohn, and Garve developed the principles laid down by Wolf until the very mention of dogma was scouted openly, and Theism itself was put forward as only the most likely among many possible hypotheses. In the revulsion against dogmatic beliefs the party of the Pietists founded by Spener towards the end of the seventeenth century found much support, while the Conscientiarians, who maintained that man's own conscience was the sole rule of faith, and that so long as man acts in accordance with the dictates of conscience he is leading the life of the just, gained ground rapidly. Some of its principal leaders were Matthew Knutzen and Christian Edlemann who rejected the authority of the Bible. The spread of Rationalism was strengthened very much by the appearance of the /Allgemeine Deutsche Bibliothek/, founded in 1764 by Nicolai in Berlin, through the agency of which books hostile to Christianity were scattered broadcast amongst a large circle of readers.