The Plurality of Worlds was a contribution to the task of transforming thought and abolishing ancient error; but the History of Oracles which appeared in the following year was more characteristic. It was a free adaptation of an unreadable Latin treatise by a Dutchman, which in Fontenelle's skilful hands becomes a vehicle for applying Cartesian solvents to theological authority. The thesis is that the Greek oracles were a sacerdotal imposture, and not, as ecclesiastical tradition said, the work of evil spirits, who were stricken silent at the death of Jesus Christ. The effect was to discredit the authority of the early Fathers of the Church, though the writer has the discretion to repudiate such an intention. For the publication was risky; and twenty years later a Jesuit Father wrote a treatise to confute it, and exposed the secret poison, with consequences which might have been disastrous for Fontenelle if he had not had powerful friends among the Jesuits themselves. Fontenelle had none of the impetuosity of Voltaire, and after the publication of the History of Oracles he confined his criticism of tradition to the field of science. He was convinced that "les choses fort etablies ne peuvent etre attaquees que par degrez." [Footnote: Eloge de M. Lemery.] The secret poison, of which Fontenelle prepared this remarkable dose with a touch which reminds us of Voltaire, was being administered in the same Cartesian period, and with similar precautions, by Bayle. Like Fontenelle, this great sceptic, "the father of modern incredulity" as he was called by Joseph de Maistre, stood between the two centuries and belonged to both. Like Fontenelle, he took a gloomy view of humanity; he had no faith in that goodness of human nature which was to be a characteristic dogma of the age of illumination. But he was untouched by the discoveries of science; he took no interest in Galileo or Newton; and while the most important work of Fontenelle was the interpretation of the positive advances of knowledge, Bayle's was entirely subversive. The principle of unchangeable laws in nature is intimately connected with the growth of Deism which is a note of this period. The function of the Deity was virtually confined to originating the machine of nature, which, once regulated, was set beyond any further interference on His part, though His existence might be necessary for its conservation. A view so sharply opposed to the current belief could not have made way as it did without a penetrating criticism of the current theology. Such criticism was performed by Bayle. His works were a school for rationalism for about seventy years. He supplied to the thinkers of the eighteenth century, English as well as French, a magazine of subversive arguments, and he helped to emancipate morality both from theology and from metaphysics.