But the two writers whose works did most to undermine revealed religion in France were Francois Marie Arouet, better known as Voltaire (1694-1778), and Jean-Jacques Rousseau (1712-1778). The former of these was born at Paris, received his early education from the Jesuits, and was introduced while still a youth to the salon of Ninon de Lenclos, frequented at this time by the principal literary opponents of religion and morality. His earliest excursions into literature marked him out immediately as a dangerous adversary of the Christian religion. He journeyed in England where he was in close touch with the Deist school of thought, in Germany where he was a welcome guest at the court of Frederick II. of Prussia, and settled finally at Ferney in Switzerland close to the French frontiers. Towards the end of his life (1778) he returned to Paris where he received a popular ovation. Poets, philosophers, actresses, and academicians vied with one another in doing honour to a man who had vowed to crush L'Infame, as he termed Christianity, and whose writings had done so much to accomplish that result in the land of his birth. The reception given to Voltaire in Paris affords the most striking proof of the religious and moral corruption of all classes in France at this period. Jean-Jacques Rousseau was born at Geneva and reared as a Calvinist. Later on he embraced the Catholic religion, from which he relapsed once more into Calvinism, if indeed in his later years he was troubled by any dogmatic beliefs. His private life was in perfect harmony with the moral tone of most of his works. He had neither the wit nor the literary genius of Voltaire, but in many respects his works, especially Le Contrat Social, exercised a greater influence on the France of his own time and on Europe generally since that time than any other writings of the eighteenth century. His greatest works were La Nouvelle Heloise (1759), a novel depicting the most dangerous of human passions; Emile, a philosophical romance dealing with educational ideas and tending directly towards Deism, and Le Contrat Social, in which he maintained that all power comes from the people, and may be recalled if those to whom it has been entrusted abuse it. The Confessions which tell the story of his shameless life were not published until after his death.
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.