I have now reviewed the context of Han astronomy so far as it relates to the Zhou bi, and tried to show how the contents and origin of the book can be understood within that context. From the Han dynasty onwards the nature of our discussion changes, for the Zhou bi is no longer the property of an active group of astronomical thinkers, but becomes a classical text subject to the labours of commentators and editors.

So far it has been necessary to be cautious in speaking of ‘the Zhou bi’, for we have had no guarantee that the term referred to anything that had yet taken on a fixed form and content. If my tentative explanation of the process by which the canon was closed is correct, the Zhou bi waited at least two centuries before Zhao Shuang saw it, and in that interval it certainly seems that the text suffered some damage and corruption. But a careful reading of the present text and its three commentaries suggests that since the time of Zhao the text has not changed apart from a few minor copyist's errors. The object of this section is to tell the story of how the Zhou bi came down to the present day. In the process it will be interesting to say something about its later influence, without becoming too involved in the historical complexities of pre-modern Chinese debates on astronomy and cosmography.

The Zhou bi in the period of division

From the break-up of the Han in AD 220 to the reunification under the Sui in AD 581, China underwent three centuries of division and political chaos.

Most previous discussions of the Zhou bi have at some point attacked the apparently obvious question of the date of the work. A recent study cites the opinions of fourteen scholars before coming to its own conclusion that ‘Therefore, the date of composition of the work must be in the early Western Han (c. 200 BC).’ We may note that the opinions cited give dates ranging from the traditional attribution to the Duke of Zhou in the eleventh century BC to the conclusions of a modern scholar that the book can be precisely bracketed into the period AD 9 to AD 84.

I do not intend to provide such a review of the work of all previous scholars on this topic before beginning my own discussion. My reasons for this are twofold. Firstly, and fairly trivially, a critical review of fourteen different opinions (each it must be said written with little or no reference to the others) is probably not the best way to help the reader towards clarity of mind on this question. More importantly, I believe that previous writers on this topic have largely misdirected their efforts in trying to find some epoch when the book as a whole could reasonably have been composed.

I suggest that two unspoken assumptions behind these efforts have lead to largely illusory results being obtained. Firstly, it is assumed that the Zhou bi is more or less a single entity which must therefore have some particular date of composition. I believe that on the contrary the different sections of the Zhou bi have extremely varied degrees of interrelation.

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’.