If Newton was supremely important among those who contributed to the climate of the Enlightenment, it is because his new system offered certainties in a world of doubts. The belief spread that Newton had explained forever how the universe worked. This cautious, devout empiricist lent the imprint of genius to the great idea of the Enlightenment: that man, guided by the light of reason, could explain all natural phenomena and could embark on the study of his own place in a world that was no longer mysterious. Yet he might otherwise have been aware more of disintegration than of progress or of theories demolished than of truths established. This was true even within the expanding field of the physical sciences. To gauge the mood of the world of intellect and fashion, of French salons or of such institutions as the Royal Society, it is essential to understand what constituted the crisis in the European mind of the late 17th century.
At the heart of the crisis was the critical examination of Christian faith, its foundations in the Bible, and the authority embodied in the church. In 1647 Pierre Gassendi had revived the atomistic philosophy of Lucretius, as outlined in On the Nature of Things. He insisted on the Divine Providence behind Epicurus’ atoms and voids. Critical examination could not fail to be unsettling because the Christian view was not confined to questions of personal belief and morals, or even history, but comprehended the entire nature of God’s world. The impact of scientific research must be weighed in the wider context of an intellectual revolution. Different kinds of learning were not then as sharply distinguished, because of their appropriate disciplines and terminology, as they are in an age of specialization. At that time philomaths could still be polymaths. Newton’s contemporary, Gottfried Wilhelm Leibniz—whose principal contribution to philosophy was that substance exists only in the form of monads, each of which obeys the laws of its own self-determined development while remaining in complete accord with all the rest—influenced his age by concluding that since God contrived the universal harmony this world must be the best of all possible worlds. He also proposed legal reforms, invented a calculating machine, devised a method of the calculus independent of Newton’s, improved the drainage of mines, and laboured for the reunification of the Roman Catholic and Lutheran churches. The influence of Locke
The writing of John Locke, familiar to the French long before the eventual victory of his kind of empiricism, further reveals the range of interests that an educated man might pursue and its value in the outcome: discrimination, shrewdness, and originality. The journal of Locke’s travels in France (1675–79) is studded with notes on botany, zoology, medicine, weather, instruments of all kinds, and statistics, especially those concerned with prices and taxes. It is a telling introduction to the world of the Enlightenment, in which the possible was always as important as the ideal and physics could be more important than metaphysics. Locke spent the years from 1683 to 1689 in Holland, in refuge from high royalism. There he associated with other literary exiles, who were united in abhorrence of Louis XIV’s religious policies, which culminated in the revocation of the Edict of Nantes (1685) and the flight of more than 200,000 Huguenots. During this time Locke wrote the Essay on Toleration (1689). The coincidence of the Huguenot dispersion with the English revolution of 1688–89 meant a cross-fertilizing debate in a society that had lost its bearings. The avant-garde accepted Locke’s idea that the people had a sovereign power and that the prince was merely a delegate. His Second Treatise of Civil Government (1690) offered a theoretical justification for a contractual view of monarchy on the basis of a revocable agreement between ruler and ruled. It was, however, his writings about education, toleration, and morality that were most influential among the philosophes, for whom his political theories could be only of academic interest. Locke was the first to treat philosophy as purely critical inquiry, having its own problems but essentially similar to other sciences. Voltaire admired what Locke called his “historical plain method” because he had not written “a romance of the soul” but offered “a history of it.” The avowed object of his Essay Concerning Human Understanding (1690) was “to inquire into the original, certainty, and extent of human knowledge; together with the grounds and degrees of belief, opinion, and assent.” For Locke, the mind derives the materials of reason and knowledge from experience. Unlike Descartes’ view that man could have innate ideas, in Locke’s system knowledge consists of ideas imprinted on the mind through observation of external objects and reflection on the evidence provided by the senses. Moral values, Locke held, are derived from sensations of pleasure or pain, the mind labeling good what experience shows to give pleasure. There are no innate ideas; there is no innate depravity.
Though he suggested that souls were born without the idea of God, Locke did not reject Christianity. Sensationalism, he held, was a God-given principle that, properly followed, would lead to conduct that was ethically sound. He had, however, opened a way to disciples who proceeded to conclusions that might have been far from the master’s mind. One such was the Irish bishop George Berkeley who affirmed, in his Treatise on the Principles of Human Knowledge (1710), that there was no proof that matter existed beyond the idea of it in the mind. Most philosophers after Descartes decided the question of the dualism of mind and matter by adopting a materialist position; whereas they eliminated mind, Berkeley eliminated matter—and he was therefore neglected. Locke was perhaps more scientific and certainly more in tune with the intellectual and practical concerns of the age. Voltaire presented Locke as the advocate of rational faith and of sensationalist psychology; Locke’s posthumous success was assured. In the debate over moral values, Locke provided a new argument for toleration. Beliefs, like other human differences, were largely the product of environment. Did it not therefore follow that moral improvement should be the responsibility of society? Finally, since human irrationality was the consequence of false ideas, instilled by faulty schooling, should not education be a prime concern of rulers? To pose those questions is to anticipate the agenda of the Enlightenment. The proto-Enlightenment
If Locke was the most influential philosopher in the swirling debates of fin de siècle Holland, the most prolific writer and educator was Pierre Bayle, whom Voltaire called “the first of the skeptical philosophers.” He might also be called the first of the encyclopaedists, for he was more publicist than philosopher, eclectic in his interests, information, and ideas. The title Nouvelles de la république des lettres (1684–87) conveys the method and ideal of this superior form of journalism. Bayle’s Historical Dictionary (1697) exposed the fallacies and deceits of the past by the plausible method of biographical articles. “The grounds of doubting are themselves doubtful; we must therefore doubt whether we ought to doubt.” Lacking a sound criterion of truth or a system by which evidence could be tested but hating dogma and mistrusting authority, Bayle was concerned with the present state of knowledge. He may have been as much concerned with exposing the limitations of human reason as with attacking superstition. Translated and abridged, as, for example, by order of Frederick II of Prussia, the Dictionary became the skeptic’s bible. The effect of Bayle’s work and that of others less scrupulous, pouring from the presses of the Netherlands and Rhineland and easily penetrating French censorship, could not fail to be broadly subversive.