from a principal of physical interpretation into a metaphysical view of the world of an atheistical character.  Naturalism is everywhere determined to have its own:  if knowledge comes from the senses, then morality must be rooted in self-interest; whoever confines natural science to the search for mechanical causes must not postulate an intelligent Power working from design, even to explain the origin of things and the beginning of motion—­has no right to speak of a free will, an immortal soul, and a deity who has created the world.  Further, as Bayle’s proof that the dogmas of the Church were in all points contradictory to reason had, contrary to its author’s own wishes, exerted an influence hostile to religion, and as, moreover, the political and social conditions of the time incited to revolt and to a break with all existing institutions, the philosophical ideas from over the Channel and the condition of things at home alike pressed toward a revolutionary intensification of modern principles, which found comprehensive expression in the atheists’ Bible, the System of Nature of Baron Holbach, 1770.  The movement begins in the middle of the thirties, when Montesquieu commences to naturalize Locke’s political views in France, and Voltaire does the same service for Locke’s theory of knowledge, and Newton’s natural philosophy, which had already been commended by Maupertuis.  The year 1748, the year also of Hume’s Essay, brings Montesquieu’s chief work and La Mettrie’s Man a Machine.  While the Encyclopedia, the herald of the Illumination, begun in 1751, is advancing to its completion (1772, or rather 1780), Condillac (1754) and Bonnet (1755) develop theoretical sensationalism, and Helvetius (On Mind, 1758; in the same year, D’Alembert’s Elements of Philosophy) practical sensationalism.  Rousseau, engaged in authorship from 1751 and a contributor to the Encyclopedia until 1757 comes into prominence, 1762, with his two chief works, Emile and the Social Contract.  Parallel with these we find interesting phenomena in the field of political economy:  Morelly’s communistic Code of Nature (1755), the works of Quesnay (1758), the leader of the physiocrats, and those of Turgot, 1774.

Our discussion takes up, first, the introduction and popularization of English ideas; then, the further development of these into a consistent sensationalism, into the morality of interest, and into materialism; finally, the reaction against the illumination of the understanding in Rousseau’s philosophy of feeling.[1]

[Footnote 1:  On the whole chapter cf.  Damiron, Memoires pour Servir a l’Histoire de la Philosophie au XVIII.  Siecle, 3 vols., 1858-64; and John Morley’s Voltaire, 1872 [1886], Rousseau, 1873 [1886], and Diderot and the Encyclopedists, 1878 [new ed., 1886].]

1. %The Entrance of English Doctrines%.