Newton had a close but small circle of people around him while writing the Principia. His odd behaviour earlier on may have been associated with mercury poisoni

Newton had a close but small circle of people around him while writing the Principia. His odd behaviour earlier on may have been associated with mercury poisoning, see Westfall's biography. It is also worth mentioning that his religious beliefs would have got Newton into serious trouble, possibly prison, certainly loss of livelihood, if they had become known, so he had to be a bit careful. I take your wider point. Newton would have seemed very odd by today's standards.