W H E N F O N T E N E L L E was composing his eloge of Isaac Newton for delivery in the Academie Royale des Sciences, he was able to consult notes by John Conduitt from which he would have learned that one of Newton's motives in beginning his work in mathematics was to investigate whether judicial astrology had any claim to validity. In writing his eloge, Fontenelle omitted any reference to this fact, an omission which, as Brian Copenhaver points out, was normal in the Age of Enlightenment. Astrology for Fontenelle was unworthy of even passing reference. 'The occultist tradition and all its claims about the powers of magic, alchemy, divination, witchcraft, and the secret arts, no longer demanded a serious response from serious thinkers.' How did it come about that such subjects had disappeared from the mainstream of European mental equipment, banished from the surface to pursue in future only a discredited existence underground? Copenhaver writes:

By the time the first edition of the Encyclopaedia Britannica appeared in 1771 the transformation was complete. The first Britannica gave only one hundred and thirty-two lines, less than a full page, to articles on astrology, alchemy, Cabala, demons, divination, the word 'occult', and witchcraft.