Why. It is a word that I frequently entertain when I study Isaac Newton. There is no scientist about whom so much is written, yet I feel that we only know so little about the man. Most Newton biographers provide us with detailed descriptions of his life and works, using the abundance of source materials available: Newton’s correspondence, descriptions by himself and others of various episodes of his life, Trinity College and Cambridge University attendance records, and so on. Every biographer, in his own way, tries to understand some of the more poignant moments in Newton’s life. Likewise, many struggle.

Take for instance the infamous events that took place in September 1693. In a short letter to Samuel Pepys, a good friend, Newton wrote:

Sir,

Some time after Mr Millington had delivered your message, he pressed me to see you the next time I went to London. I was averse; but upon his pressing consented, before I considered what I did, for I am extremely troubled at the embroilment I am in, and have neither ate nor slept well this twelve month, nor have my farther consistency of mind. I never designed to get anything by your interest, nor by King James’s favour, but am now sensible that I must withdraw from your acquaintance, and see neither you nor the rest of my friends any more, if I may but leave them quietly. I beg your pardon for saying I would see you again, and rest your most humble and most obedient servant,

Is: NEWTON

A few days later he wrote another letter, to John Locke, which sheds more light upon the “embroilment” that Newton was “extremely troubled” about:

Sir

Being of opinion that you endeavoured to embroil me with woemen & by other means I was so much affected with it as that when one told me you were sickly & would not live I answered twere better if you were dead. I desire you to forgive me this uncharitableness. For I am now satisfied that what you have done is just & I beg your pardon for my having hard thoughts of you for it & for representing that you struck at the root of morality in a principle you laid down in your book of Ideas & designed to pursue in another book & that I took you for a Hobbist. I beg your pardon also for saying or thinking that. there was a designe to sell me an office, or to embroile me.

I am

your most humble & most unfortunate Servant

Is. NEWTON.

Apparently, Newton was extremely upset about something that Locke and Pepys had tried to do: to “embroil him with weomen” and to “sell him an office”, that when Locke told him he suffered from an incurable disease, Newton’s reply was, “Drop dead.” Pepys immediately discussed the letter he received with said John Millington, a Fellow of Magdalene College, Cambridge, expressing his great concern for Newton. In his reply to Pepys, Millington writes that before he could ask Newton any question, Newton told him

that he had writ to you a very odd letter, at which he was much concerned; added, that it was in a distemper that much seized his head, and that kept him awake for above five nights together, which upon occasion he desired I would represent to you, and beg your pardon, he being very much ashamed he should be so rude to a person from whom he hath so great an honour. He is now very well, and, though I fear he is under some small degree of melancholy, yet I

think there is no reason to suspect it hath at all touched his understanding.

Newton seemed very embarrassed about the entire matter. When John Locke wrote to him a few days later expressing his gratefulness for Newton’s apology (“.. it ives me hopes I have not lost a friend I soe much valued”) though also confessing that he could not be but “mightily troubled” that Newton had “soe many wrong & unjust thoughts about him”, Newton by ways of an explanation for his behaviour answered that he “had not slept an hour a night for a fortnight together & for 5 nights together not a wink.”

Now this entire episode has been read by Newton biographers and historians of science in many ways. Some tried to connect it with his alchemy, that he had been performing experiments for months on end, might have suffered lead-poisoning, and as a result suffered from delusions. Others took it for temporary madness, maybe related to his break-up with the young Swiss prodigy Nicholas Fatio de Duillier, about whom Newton was extremely fond. It is an episode that has also been used and abused by those that tried to reconfigure Newton as a rationalistic Enlightenment figure, explaining his alchemical and religious writings as the result of Newton’s alleged derailment.

There are all sorts of answers to these and other readings of this mysterious period in Newton’s life. But all the time I here myself asking: why? Not why did Newton do so and so, but why do biographers come up with all sort of fancy explanations? Because the truth is likely much simpler. Why don’t we just believe what the letters tell us? In 1693, Newton was fifty years of age. He had spend over thirty years in Cambridge, longer than most Cambridge dons. When reaching a certain age, many scholars would find themselves a position in London, or a vicarage, and marry. I think Newton’s friend Millington, Locke and Pepys simply tried to provide Newton with exactly that. Maybe they invited some suitable marriage candidates to a London dinner party, and introduced them to Newton? They definitely discussed possible job opportunities, as the letter to Pepys shows. It seems easiest to assume that this is what happened. Unfortunately for all involved, this was not to Newton’s liking. The job discussions might have been the lesser evil; after all, within a few years Newton moved to London to take up a position at the Mint, and would within a few years become one of the most important people in British finance. But the weomen, ah, that was a different matter all together…

We don’t know much about Newton’s sexuality (but please do watch Rob Iliffe’s take here). It has been suggested that he was a homosexual – hence his intimate feelings for Fatio – but we have no evidence for this. On his death bed, Newton did confess that he was a still a virgin. To me, it seems that Newton simply wasn’t interested in women – nor men. He had devoted his life to something beyond carnal love and – though not formally – sworn to celibacy, a vow he kept.

Why? We might never now.