Sir Isaac Newton's influence on the modern scientific worldview is profound, and despite a paradigm change in physics a century ago through the discoveries of the quantum world, many people still see the world through the prism (no pun intended) of 'Newtonian' physics. Indeed, that scientific philosophy has now become synonymous with a purely mechanical cosmos, stripped of superstition, magic, and even the impact of consciousness, via the loss of free will. It is a worldview, however, that may have horrified Newton himself.
When the great scientist died in 1727, he left behind him a substantial estate, including a library with nearly 1800 books and a large number of manuscripts. He did not, however, leave behind a will. After much debate and argument, it was decided that the manuscripts would be examined by Dr. Thomas Pellet, a member of the Royal Society, with the intention to publish and sell them. Once Pellet had looked over the papers though, the idea of releasing them publicly quickly receded - in the end, only one out of eighty-one items was published. The rest were tagged “Not fit to be Printed”:
Many of these manuscripts were of a theological nature. Theology as such was of course not an issue, but, on the contrary, an asset: After all, Newton was one of the true defenders of the faith against popish plots and Cartesian deism. But Mr. Pellet must have had a bad time when he realised that Newton’s theology was of a very heretical nature. Leafing through piles of apocalyptical interpretations and anti-Athenasian rants, Pellet understood that Newton’s anti-Trinitarianism and idiosyncratic interpretation of Church history should not be made public, lest the image of the great Newton be blemished.
...At the time of his death, Newton’s library contained at least 138 books on alchemy, many of which showed signs of extensive use. This was not unheard of for ‘enlightened scientists’: some were avid book collectors, interested in all sorts of curiosities. The manuscripts, however, proved that Newton’s interest in alchemy went far beyond curiosity. There are thousands of folios with Newton copying from all sorts of alchemical manuscripts, and recent scholarship has shown that he must have been actively involved in the circulation of alchemical knowledge. Not only did he read and copy out entire tracts, Newton even gave detailed descriptions of alchemical experiments he performed himself. How could a hero of modern science be engaged in such occult and ‘unscientific’ practices?
The economist John Maynard Keynes purchased Newton's works - many of which were encoded and needed deciphering - at auction in 1942, and on discovering the alchemical nature of much of it was moved to state that "Newton was not the first of the age of reason, he was the last of the magicians".
For those interested in learning more, see the Nova feature Newton's Dark Secrets embedded below: