IN consequence of the wide circulation of the Life of Sir Isaac Newton, which I drew up for the "Family Library" in 1831, I was induced to undertake a larger work, in order to give a more detailed account of his Life, Writings, and Discoveries. For this purpose, I applied in 1837 to the Honourable Newton Fellowes one of the trustees of the Earl of Portsmouth, for permission to inspect the Manuscripts and Correspondence of Sir Isaac, which, through his grand-niece, Miss Conduitt, afterwards Lady Lymington, had come into the possession of that noble family. Mr. Fellowes kindly granted my request, and his amiable and accomplished son, Mr. Henry Arthur Fellowes, who, had he lived, would now have been Earl of Portsmouth, met me in June 1837, at Hurtsbourne {sic} Park, to assist me in examining, and making extracts from, the large mass of papers which Sir Isaac had left behind him.

In this examination our attention was particularly directed to such letters and papers as were calculated to throw light upon his early and academical life, and, with the assistance of Mr. Fellowes. who copied for me <viii> several important documents, I was enabled to collect many valuable materials unknown to preceding biographers.

After the death of Sir Isaac, his nephew, Mr. Conduitt, drew up a memorial, containing a sketch of his life, for the use of Fontenelle, the Secretary to the Academy of Sciences in Paris, whose duty it was to write his Eloge, as one of the eight Associates of the Academy. This memorial was published by Edmund Turnor, Esq., in his "Collections for the History of the Town and Soke of Grantham," and was supposed to contain all the information that Mr. Conduitt could collect from persons then alive, and from other sources, respecting Sir Isaac's life. This, however, was a mistake. After the publication of Fontenelle's Eloge, Mr. Conduitt resolved to draw up a Life of his illustrious relative, and, with this view, he wrote the following letter, requesting the assistance of Sir Isaac's personal friends --[1]

"6th February, 1727/8.

SIR, -- I have taken the liberty to trouble you with some short hints of that part of our honoured friend. Sir I. Newton's life, which I must beg the favour of you to undertake, there being nobody, without dispute, so well qualified to do it as yourself. I send you, at the same time, Fontenelle's Eloge, wherein you will find a very <ix> imperfect attempt of the same kind; but I fear he had neither abilities nor inclination to do justice to that great man, who had eclipsed the glory of their hero, Descartes. As Sir I. Newton was a national man, I think every one ought to contribute to a work intended to do him justice, particularly those who had so great a share in his esteem as you had, and as I pretend to nothing more than to compile it, I shall acquaint the public in the Preface, to whom they are indebted for each particular part of it.

"I am persuaded, that the hints I have sent you are very imperfect, and that your own genius will suggest to you many others much more proper and significant, and I beg of you to put down every thing that occurs to your thoughts, and you think fit to be inserted in such a work.

"I conjure you not to put off what I take the liberty to recommend to you. As on one hand the complying with my request will be a mark of your gratitude to your old friend, and an eternal obligation on me, so your delaying it will be the most mortifying disappointment to,


Your most humble Servant,



Although Mr. Conduitt had at this time resolved to compile a Life of Sir Isaac, and had obtained much information from Dr. Stukely, Mr. Wickins, and Dr. Humphrey Newton of Grantham, yet he seems to have so far relinquished his design, that in June 1729, nearly eighteen months after the date of his letter, he intimates to a friend[3] that "he has some thoughts of writing the Life of Sir Isaac Newton himself." That he made the attempt, appears from an indigested mass of manuscript which he has left behind him, and which does not lead us to regret much that he abandoned his design. The materials, however, which he obtained from Mrs. Conduitt, and from the friends of Newton then alive, are of great value; and, in so far as Mr. H. A. Fellowes and I could make an abstract of these and other manuscripts during a week's visit at Hurtsbourne {sic} Park, I have availed myself of them in composing the first volume of this work, which was printed before the papers themselves came into my hands.

Before I began the second volume, which contains the history of the Fluxionary controversy, and the Life of Newton subsequent to the publication of the first edition of the Principia, I had the good fortune to obtain from the Earl of Portsmouth, through the kindness of Lord Brougham, the collection of manuscripts and correspondence which the late Mr. H. A. Fellowes had examined and arranged <xi> as peculiarly fitted to throw light on the Life and Discoveries of Sir Isaac. In these manuscripts I found much new information respecting the history of the Principia, which, though it might have been more appropriately placed in the first volume, I have introduced into those chapters of the second which relate to the period when the other editions of the Principia were published.

In the different controversies in which Newton's discoveries involved him, his moral character had never been the subject of suspicion. In Hooke, he found a jealous but an honest rival, who, though he claimed discoveries which substantially belonged to Newton, never cast a reproach upon his name; and amid all the bitterness of the Fluxionary controversy, Leibnitz and Bernoulli, and their anonymous auxiliaries, never hesitated to acknowledge the purity of Newton's motives, and the scrupulous correctness of his conduct. It was reserved for two English astronomers, the one a contemporary and the other a disciple, to misrepresent and calumniate their illustrious countryman.

In 1835 the scientific world was startled by the publication of Baily's Life of Flamsteed, a huge volume, deeply affecting the character of Newton, and, strange to say, printed, and circulated throughout the world, at the expense of the Board of Admiralty. The friends of the great philosopher were thus summoned to a painful controversy, which, had it been raised in his lifetime, would <xii> have been summarily extinguished; but a century and a quarter had elapsed before the slumbering calumnies revived, and it was hardly to be expected that the means of defence would have enjoyed the same vitality. Under these circumstances Mr. Fellowes and I anxiously searched, but in vain, for the letters of Flamsteed to Newton, and other relative documents which were necessary for his defence. In this difficulty, some of the admirers of Newton, among whom I must mention my friend Mr. Robert Brown, the distinguished President of the Linnean Society, sent me some important facts; but valuable as they were, they were not sufficient to refute the calumnies of the Astronomer-Royal. From this embarrassment, however, I have been relieved by the receipt of all Flamsteed's letters and other important papers which Newton had carefully preserved, and which Mr. Fellowes had discovered and set aside for my use. With these documents I trust I have been able, though at a greater length than I could have wished, to defend the illustrious subject of this work against a system of calumny and misrepresentation unexampled in the history of science.

When I published my Life of Newton in 1831, I had not seen his correspondence with Mr. Cotes and other mathematicians in the Library of Trinity College. Mr. Halliwell, however, who had made copious extracts from these manuscripts, kindly put them into my hands; but the subsequent publication of the correspondence by Mr. <xiii> Edleston, has enabled me to make a more advantageous use of these valuable materials.

Dr. Monk, Bishop of Gloucester and Bristol, had "often expressed in private a wish and request that some one of the many accomplished Newtonians who are resident in that society would favour the world by publishing the whole collection," [4] and I have no doubt that it was from this public expression of it, in his able and interesting Life of Dr. Bentley, that the Master and Seniors of Trinity College resolved to publish the correspondence.

This valuable work, edited by Mr. Edleston, Fellow of Trinity, is a most important contribution to the History of Mathematical and Physical Science. The admirable synopsis which it contains of Newton's life; the learned and able annotations illustrative of his history; and the explanatory notes on the letters themselves, throw much light on the subjects to which they refer, and have been of essential service to me in the composition of this work. But in addition to the obligations which I owe to Mr. Edleston, in common with every friend of science, I have to acknowledge others of a more personal kind. During the printing of the second volume, which he has had the kindness to peruse, I have received from him much new and important information, and availed myself of his judicious criticisms and useful suggestions.

To Professor De Morgan, to whom the public owes a <xiv> brief but interesting biographical sketch of Newton, and who has carefully investigated various points in the Fluxionary controversy, I have been indebted for much information, and for his kind revision of the sketch I had given of the early history of the Infinitesimal Calculus. On a few questions in the life of Newton, and the history of his discoveries, my opinion differs somewhat from his; but I have been able to confirm, from the documents in my possession, many of his views on important points which he was the first to investigate and to publish.

From my late amiable and distinguished friend Professor Rigaud of Oxford, too early cut off in his scientific career, I obtained valuable aid whenever I encountered difficulties or required information. His "Historical Essay on the Principia," which he generously offered to withhold from the public, till I had finished the present work, is a most important contribution to the history of Newton's discoveries, and I am glad to be able to complete the correspondence between Newton and Halley, which Mr. Rigaud was the first to publish in its genuine state.

The Rev. Jeffry Ekins, Rector of Sampford, whose family, from their connexion with Newton, have been long in possession of several of his theological manuscripts and letters, has obligingly sent me copies of many of them, and has otherwise favoured me with much useful information.

To Lord Brougham, Sir John Lubbock, Mr. Cutts <xv> Barton, and other friends, I have to return my best thanks for the assistance they have given me.

In concluding this Preface, I can hardly avoid referring to Sir Isaac Newton's religious opinions. In the chapter which relates to them I have touched lightly, and unwillingly, on a subject so tender; and in publishing the most interesting of the manuscripts in which these opinions are recorded, I have done little more than submit them to the judgment of the reader. Though adverse to my own, and I believe to the opinions of those to whom his memory is dearest, I did not feel myself justified, had I been so disposed, to conceal from the public that which they have long suspected, and must have sooner or later known. What the gifted mind of Newton believed to be truth, I dare not pronounce to be error. By the great Teacher alone can truth be taught, and it is only at his tribunal that a decision will be given on those questions, often of words, which have kept at variance the wisest and the best of men.


ST. ANDREWS, May 12, 1855.

[1] This letter is docqueted by Conduiitt, "Letter sent by me concerning Sir I. N.'s Invention."

[2] I have not succeeded in ascertaining to whom this letter was addressed. It was probably a circular sent to more than one person. I have found a letter from John Craig, and a paper by De Moivre, which have the appearance of being answers to it, but the dates of both are earlier than that of Conduitt's letter. In a letter dated April 16, 1729, Conduitt made a similar application to Professor Machin.

[3] In a letter on the subject of a large "monumental picture to Newton's memory," for Conduitt himself. This letter is docqueted, "Sent to Westgarth," who seems to have been then in Italy.

[4] Life of Bentley, p. 180.

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