16. He was a solitary and reclusive, preferring his own company to that of others
Over time, Isaac Newton developed the personality which led him to prefer to be alone, avoiding social contacts except when necessary for the advancement of his work. In his writings and those of his contemporaries, he exhibited little in the way of a sense of humor, and he did not easily share his achievements with others by making note of their contributions. He did not express his emotions other than in bursts of anger; other feelings remained under strict self-control. He did not speak or write of his own desires, and the only indications of his possessing a sense of remorse were in the lists of “sins” he prepared for himself while in his youth.
He was not free from a sense of sexual desire, since he wrote of the means to control it, and thus remain chaste, a condition in which he apparently remained throughout his life. “The way to chastity is not to struggle with incontinent thoughts but to avert the thoughts by some imployment (sic), or by reading, or by meditating on other things, or by convers”, Newton told a relative late in his lifetime. The only record of any potential romantic involvement was an adolescent one, before he began his academic career. Probably the best description of Newton’s personality comes from Humphrey Newton, who served as his secretary for a time at Trinity College. “His behavior was mild and meek, without anger, peevishness, or passion, so free from that, that you might take him for a stoic.” But clearly, he was not without his demons, as human as are all.
Where do we find this stuff? Here are our sources:
“Mercury Poisoning: A probable cause of Isaac Newton’s physical and mental ills”. L. W. Johnson, M. L. Wobarsht, Notes and Records, The Royal Society Journal of the History of Science. July 1, 1979
“Balancing Newton’s Mind: his singular behavior and his madness of 1692-93”. Milo Keynes, Notes and Records, The Royal Society Journal of the History of Science. September 20, 2008
“The Newton-Leibniz Controversy”. Gerald L. Alexanderson, Leonard F. Klosinski, Bulletin of the American Mathematics Society. February 1, 2016