From about 1746 onwards, the rationalist movement in eighteenth-century France rapidly widens and deepens. The number of rationalistic writers, despite the press laws which in that age inflicted the indignity of imprisonment on half the men of letters, increased from decade to decade, and the rising prestige of the philosophes in connection with the Encyclopédie (1751-72) gave new courage to writers and printers. At once the ecclesiastical powers saw in the Encyclopédie a dangerous enemy; and in January, 1752, the Sorbonne condemned a thesis "To the celestial Jerusalem," by the Abbé de Prades. It had at first (1751) been received with official applause, but was found on study to breathe the spirit of the new work, [997] to which the Abbé had contributed, and whose editor, Diderot, was his friend. Sooth to say, it contained not a little matter calculated to act as a solvent of faith. Under the form of a vindication of orthodox Catholicism, it negated alike Descartes and Leibnitz; and declared that the science of Newton and the Dutch physiologists was a better defence of religion than the theses of Clarke, Descartes, Cudworth, and Malebranche, which made for materialism. The handling, too, of the question of natural versus revealed religion, in which "theism" is declared to be superior to all religions si unam excipias veram, "if you except the one true," might well arouse distrust in a vigilant Catholic reader. [998] The whole argument savours far more of the scientific comparative method than was natural in the work of an eighteenth-century seminarist; and the principle, "Either we are ocular witnesses of the facts or we know them only by hearsay," [999] was plainly as dangerous to the Christian creed as to any other. According to Naigeon, [1000] the treatise was wholly the work of de Prades and another Abbé, Yvon; [1001] but it remains probable that Diderot inspired not a little of the reasoning; and the clericals, bent on putting down the Encyclopédie, professed to have discovered that he was the real author of the thesis. Either this belief or a desire to strike at the Encyclopédie through one of its collaborators [1002] was the motive of the absurdly belated censure. Such a fiasco evoked much derision from the philosophic party, particularly from Voltaire; and the Sorbonne compassed a new revenge. Soon after came the formal condemnation of the first two volumes of the Encyclopédie, of which the second had just appeared. [1003]