At the start of the eighteenth century, three main intellectual trends dominated the philosophical world: the scepticism of Pierre Bayle and Bishop Huet, irreligious scepticism, and a new appreciation of the power of reason in the light of Isaac Newton's achievements. We will begin this chapter with Newton (1642–1727), whose popular image played a great role in eighteenth-century thought. As Alexander Pope said, “Nature and nature's mysteries lay hid in the night. / God said, let Newton be, and all was light.”
Newton himself has turned out to be much more than simply a very brilliant scientist. The massive amount of his writing, more than half of which is still unpublished, shows him to have been very concerned about religious matters and to have held quite unorthodox anti-Trinitarian beliefs, which may, as James Force argues, have been connected to his scientific beliefs. In the early part of the century, his still unpublished religious views were known to only a small coterie of disciples, though his scientific views, including the general religious ones in the second edition of his Principia mathematica (Mathematical principles), were widely appreciated. His scientific achievements dominated the “scientific outlook” of the time, while G. W. Leibniz's alternative system was largely passed over until much later in the century, since some of his basic philosophical statements were not published until then. Many philosophers and scientists sought to combine the Newtonian scientific outlook with a more “reasonable” set of religious beliefs.
Below, we will begin with Newton himself, then address his quarrel with Leibniz.