In the course of a long life Isaac Newton made many enemies: Francis Linus (or Hall), Robert Hooke, John Flamsteed, Gottfried Wilhelm Leibniz, Johann I Bernoulli. Of these Leibniz was by far the greatest intellect and above all an outstanding mathematician and philosopher. Newton defeated them all and outlived them all except the last, twenty-five years his junior.

It was a sad chronology that brought two such inventive mathematicians as Newton and Leibniz to live in the same age; never were temperaments and intellectual characters more at odds. Almost the only feature that they had in common was Protestant piety, yet even in appealing to God the Creator they could not agree. In mathematics and its applications to celestial mechanics, and more particularly in the development of the calculus, though the methods promulgated by the two men were equivalent, they had been reached and were justified by wholly distinct arguments. Newton was by choice a geometer, Leibniz an algebraist; the difference does not of course imply that they could not tackle the same problems. J. E. Hofmann has written that Leibniz’s “first major [mathematical] discovery in Paris [in 1673] originated in thoughts strongly influenced by considerations of logic and philosophy – and as so often with Leibniz, was not fully established but came as the fruit of a particular insight observed in simple examples and generalised by a stroke of genius.”

In the mid seventeenth century, mathematics and science were accorded no greater importance in the University of Cambridge than in other universities throughout Europe. One hundred years later the position was quite different. Though the traditional academic ‘exercises’ still took place, the ability of graduands was judged by their performance in the Senate House Examination or Mathematical ‘Tripos’. During the seventeenth century, traditions of teaching mathematical subjects, ‘natural philosopy’ (i.e., physical science), and medicine were modernised in many European countries, including Britain, but the influence of Isaac Newton (1642–1727) brought about particularly swift and far-reaching changes at Cambridge, his own university.

As Lucasian Professor of Mathematics for nearly thirty years from 1669, Newton set some of his own discoveries before his auditors (few enough) without ever proposing any general reform of education, while in private – in documents long unread and showing little desire to alter the balance between humane and mathematical or scientific studies – he increased the latter's importance. Most interesting in these drafts is the new role of a mathematically based natural philosophy, for which students were to be prepared by courses in geometry and mechanics, that is, ‘the demonstrative doctrine of motions … For without a judgement in these things a man can have none in [natural] philosophy.’ The latter subject Newton explained as the investigation of those matters which he himself had so far advanced in his Mathematical Principles of Natural Philosophy [Principia] (1687), beginning with an understanding of time, space, body, and motion, moving on to rational and fluid mechanics, astronomy and cosmology, then ending ‘if the [lecturer] have skill therein’ with knowledge of minerals, vegetables, and anatomy.

I have endeavoured here to write an account of the greatest mind in British history. If any names of Englishmen survive into the remote future, those of Shakespeare and Newton will surely be among them. The latter was above all things a mathematician and a natural philosopher, but he also gave deep scholarship and profound thought to ancient history, especially to the early history of Christianity, the unravelling of sacred prophecy and even to monetary theory and practice. On all these topics he left vast accumulations of manuscript material.

In this book attention is chiefly directed to Newton the mathematician and philosopher. As such he worked his great transformation in human thought. Even so, a volume of modest size permits no very technical treatment of his researches in mathematics and mechanics, and in experimental optics. For such treatment the reader may turn to D. T. Whiteside's epoch-making edition of Newton's Mathematical Papers, the parallel volumes of Optical Papers (in progress) edited by Alan E. Shapiro, and very many specialist studies by these and other scholars. As for Newton's daily life and personal pursuits, for all the huge amount of material by and concerning Newton now accessible to us, these are shadowy at all periods of his life. I have not tried to emulate here Frank E. Manuel's psychological analysis of Newton in terms of theories whose validity seems to be doubtful. In general, I believe it imprudent to try to interpret Newton's life and writings in terms of single factors, whether these be his infantile experiences, his reading of the strange books of the alchemists, his faith in God or even his confidence in number and measure.

Humphrey Newton's Recollections

In the last year of the reign of King Charles II, according to his own recollection, Humphrey Newton came to Trinity College, Cambridge, from Grantham School to be sizar to his great namesake, Isaac. Neither Newton admitted or claimed relationship with the other. Humphrey remained with Isaac for five years before returning to Grantham as a country physician, during which period he lived in some intimacy with the Lucasian Professor, chiefly serving as his copyist. John Conduitt, after Isaac's death, sought in 1728 Humphrey's recollections of him, first published by Brewster in 1855. With all its obvious imperfections and silliness, Humphrey's is the only personal record of Newton's daily life from someone who had every opportunity for close and long observation.

Humphrey was much more struck by Newton's manners than by his mind, which was beyond his appreciation. His only memory of the Principia, after having copied it, was that some of the scholars in Cambridge to whom Newton bade him take presentation copies, declared ‘that they might study seven years before they understood any thing of it’. (They might have spent seven years in worse ways.) He remembered that Newton kept a five-foot-long [refracting] telescope at the head of the stairs leading from his rooms to the garden below, but all he could say of Newton's study of astronomy was that ‘several of his observations about comets and the planets may be found scattered here and there in a book entitled The Elements of Astronomy by Dr. David Gregory.’

As will be evident from this biography, Newton carefully preserved his notebooks and papers, including his correspondence, throughout his life, accumulating a mass of folded bundles whose contents were not in all cases readily identifiable. After his death, as part of the settlement of his intestacy, John and Catherine Conduitt received undivided rights to this great mass. Only two manuscripts (The Chronology of Ancient Kingdoms Amended and The System of the World) were found suitable for immediate sale to booksellers for publication; otherwise little from this mass reached print during the eighteenth century, even in Samuel Horsley's collected edition of Newton's writings (1779–85). While Horsley had been able to make only a cursory examination of the papers and remained unperceptive of their significance, Newton's first real biographer, Sir David Brewster, amended and amplified a book already in proof from biographical (and some other) materials selected for him by Henry Arthur Fellowes in 1837.

Fellowes was a nephew of the then Earl of Portsmouth, owner by inheritance of the Newton papers, which were preserved at his seat, Hurstbourne Park in Hampshire. His family name was Wallop; the younger Catherine Conduitt (Newton's ‘Kitty’) had married John Wallop in 1740, becoming titular Viscountess Lymington by the creation of the earldom of Portsmouth for her father-in-law in 1743.

Meanwhile, before Brewster's time many letters and documents sent by Newton to others (including Collins, Boyle and Locke) had reached print, as had extracts or paraphrases of the memoirs of Newton compiled by John Conduitt before and after Newton's death. Some of these Newtonian scraps have since been rejected as false.

Newton served the State in a variety of capacities for thirty years; he not only embodied in his own person (as Pepys had formerly done at the Admiralty and his contemporary William Lowndes did at the Treasury) a novel conception of the high-ranking, efficient, professional civil servant, but helped to established the character of the English government official in the parliamentary age: as a man of integrity, unremitting in his attention to business, thoroughly competent in matters of detail yet no mere clerk – a head of department able to realize ministerial policy in concrete terms.

As we have seen, Newton's association with government began with his election as a university Member of Parliament for Cambridge in January 1689. After the thirteen months – including a long summer recess – of the Convention Parliament no one at Cambridge seems to have wished to propose Newton for a second term. Two years after his translation to the mastership of the Mint (25 December 1699) he was again nominated and elected Member of Parliament for the university. He is known to have supported Halifax and the Whig Junto on a vote of confidence but was in general no more obvious in the House of Commons than before. When the Parliament was dissolved after a few months (2 July 1702) Newton refused to stand again unless unopposed: ‘To solicit and miss for want of doing it sufficiently, would be a reflection upon me, and it's better to sit still.”

Leibniz and Newton

The link between Britain and G. W. Leibniz, now firmly stationed at Hanover though often travelling about Europe in the interests of his master, was decisively broken by the sudden death of Henry Oldenburg early in September 1677. A last letter from him to Leibniz had advised the philosopher to expect no speedy response to his recent mathematical letters from either Collins or Newton; the silence in fact was to last for fifteen years. Whether or not Newton would have been willing to carry on the correspondence with Leibniz, he lacked easy means to do so. Both Collins and Newton studied Leibniz's letters, however. We have no opinion at this stage about Leibniz's mathematical discoveries from Newton himself, but it would seem that he, Collins and John Wallis agreed that Leibniz had (like James Gregory) made an independent discovery of the ‘method of series’ based on the work of earlier mathematicians which he had developed in his own way, and to which he had added an improved ‘method of tangents’. Collins imagined (mistakenly) that Leibniz had gleaned something from Barrow's lectures, and suggested that the Royal Society might print Leibniz's letters to Oldenburg. He never hinted that Leibniz owed anything to Newton.

As previous chapters have shown, Newton did little to promote his calculus in the twenty years after 1671. Leibniz too gave few signs of his slumbering mathematical genius for eight years after leaving Paris.

Newton's Teaching in Cambridge

The greater part of Newton's original work in mathematics and science was first expressed in the form of university lectures. This is true of his researches in geometrical and experimental optics, of his discoveries in theoretical and celestial mechanics, and of his investigations in algebra and some other parts of mathematics. He never lectured upon calculus, no doubt believing that this topic was far beyond the reach of his student auditors; and he did not lecture either upon his chemical, alchemical, biblical and historical studies, not only for the reason that they lay far outside the scope of his professorship. The details of Newton's lecturing are formally known to us from the manuscripts of his optical lectures (in two versions), of the Arithmetica universalism and of the De motu corporum which he submitted to the University Library in accordance with the statutes of his professorship – or nearly so! These statutes, indeed, required the Lucasian Professor of Mathematics to deliver upwards of twenty lectures in each academic year, neatly written copies of ten of them to be deposited with the vice-chancellor in the following year. But although these statutes had been drawn up only in 1663, when the professorship was founded by Henry Lucas, their provisions were at once disobeyed. While his predecessor, Isaac Barrow, had probably lectured in two terms of each year, Newton went to the Schools in one only, half an hour being reckoned a near enough approach to the statutory ‘about one hour’.

The Reflecting Telescope

The close of the year 1671 was marked by the public appearance of Newton upon the national stage of the Royal Society of London. It is strange that with both Newton and his arch-rival Leibniz this event happened in the same unexpected and unlikely way: each of them presented a gadget to the Royal Society. In Leibniz's case it was an arithmetical machine, a toothed-wheel device of the type pioneered by Blaise Pascal, in Newton's his miniature reflecting telescope. Newton's introduction to the Society (December 1671) preceded Leibniz's by just over a year. Both men were, for their pains, severely mauled by Robert Hooke, with assertions that their inventions were valueless and much inferior to his own schemes. Both were deeply wounded by this reception, though also conscious of the warmer welcome extended to them by other Fellows of the Royal Society, not least its Secretary, Henry Oldenburg.

Newton and Leibniz certainly did not meet during this first visit of Leibniz to London (January–March 1673), though before long Collins would be sharing with Leibniz an outline of the mathematical progress accomplished by James Gregory and Isaac Newton. Yet curiously there may be a link between Leibniz and Newton's reflecting telescope. In a letter that Oldenburg received probably about 20 October 1671, Leibniz (writing about the innovations made by a young German optician) mentioned ‘Tubos Catadioptricos, quales mihi in mentem venerunt’ (‘reflecting-refracting tubes, such as occurred to my mind’). No explanation of this phrase has been found, but Newton had certainly invented a catadioptrical telescope.

Warden of the Mint, 1696

It is a fair guess that Newton was never fully content with his professorial and collegiate life in Cambridge after the university had sent him to Parliament in 1689. Indeed, it may be that his eye began to rove as early as 1687, in the period of lassitude that must inevitably have followed the intense and exciting task of bringing the Principia to a conclusion in the summer of that year. By that time the acquaintance or friendship between Samuel Pepys PRS and Isaac Newton must have been established; besides the Royal Society, Christ's Hospital mathematical school had brought the two men together. Pepys was then at the height of his career and of his influence. At the peak of his psychological crisis in 1693 Newton wrote to Pepys: “I never designed to get anything by your interest, or King James favour,” an obvious allusion to days before the Revolution, after which Pepys's influence was nil. If we may read this anxious denial as evidence that there really was some such talk or manoeuvre (as with Newton's parallel denial to Locke), it must have occurred in 1687 or 1688.

Similarly and in the same disturbed frame of mind, Newton wrote to Locke: “I beg your pardon also for saying or thinking that there was a designe to sell me an office.” In this case, letters do hint at Locke's enlisting the help of the Earl of Monmouth (a favourite of William Ill's and recently First Lord of the Treasury) who had been a patron of Locke himself.

Our society depends upon science, and yet to many of us what scientists do is a mystery. The sciences are not just collections of facts, but are ordered by theory, and this is where Einstein's famous phrase about science being a free creation of the human mind comes in. Science is a fully human activity; the personalities of those who practise it are important in its progress and often interesting to us. Looking at the lives of scientists is a way of bringing science to life.

By the time of his death in 1727 Newton stood as the representative figure of modern science. His name was something to conjure with, evoking ideas of the absent-minded professor, the solitary genius, and the power of mathematical and experimental science to answer questions about the world. He became a key figure in the Enlightenment of the eighteenth century, and his work correspondingly aroused unease among Romantics who saw his science as inhuman and reductive.

A mythical Newton, a new Adam born on Christmas Day and nourished by an apple from the tree of knowledge, came to obscure the real man who had worked in dynamics, astronomy and optics, and less successfully in chemistry, to synthesize the work of great predecessors such as Kepler, Galileo, Descartes and Boyle. Rupert Hall comes to this biography after editing the correspondence of both Newton himself and also Henry Oldenburg, the first secretary of the Royal Society and the editor of its journal. He has also edited some of Newton's unpublished papers.

Newton first took up residence in a house in Jermyn Street (now number 88) towards the socially superior western end, in which he lived four years, then from 1700 to 1709 in the next-door house (87). Sir Robert Gayer was a near neighbour (letter 710). Leases for these properties had been granted by the trustees of the Earl of St Albans in 1665, and the buildings were put up about ten years later. Number 87 is at present undergoing total reconstruction and number 88 is a shop (‘James Bodenham’) with the original brick structure preserved.

After his brief sojourn in Chelsea (where he lived at the east end of Paradise Row) Newton moved to 35 St Martin's Street, a few yards south of Leicester Fields (now Square), an area just newly developed by Lord Leicester. There he lived in a house built c.1695 from 1711 to 1725. It had three storeys with basement and was built of brick with a tiled roof; there was a bracketed hood over the front door. On the main floors were rooms front and back with a projecting ‘closet’ wing at the rear. The ground-floor front room was panelled. According to a footnote in the Survey of London Newton had a small observatory built at the top of the house.

In Kensington he lived (in lodgings?) in Orbell's Buildings, a little north of Kensington High Street and west of Church Street, a site now occupied by Bullingham Mansions. He already owned property south of the High Street.