The Passion of Isaac: Becoming Sir Isaac Newton
Isaac Newton’s Hidden Work and Intellectual Evolution
Introduction
Sir Isaac Newton’s genius extended far beyond his published works in physics and mathematics. In private, Newton developed a trove of mathematical innovations and engaged in intense theological and alchemical studies that he deliberately kept from public view. Understanding Newton’s unpublished mathematical work alongside his psychological influences and mystical pursuits reveals a more complete picture of how his ideas evolved. This report examines Newton’s secret equations and manuscripts, the personal experiences and anxieties that shaped his intellectual life, the interplay of his scientific ideas with his theology and alchemy, and a timeline mapping the development of his thought. In doing so, we contextualize Newton’s hidden work within the rich psychological and historical backdrop of his life, drawing on his private notebooks, correspondence, and modern scholarly analysis.
Synthesis of Newton’s Unpublished Mathematics
Newton’s creative output in mathematics was astonishing – yet much of it remained hidden for years or even decades. During the mid-1660s, while still in his early 20s, Newton quietly invented calculus (his method of fluxions) and discovered infinite series expansions. In a 1665–1666 notebook (the “Waste Book”), Newton derived results such as the general binomial series and methods for finding tangents and curvatures of curves (Isaac Newton (1642 - 1727)). These breakthroughs were communicated privately to a few colleagues after 1669 but not published widely at the time (Link). Newton’s notes show that by autumn 1665 he had formulated calculus in terms of instantaneous change (“fluxions”) – a method he devised independently through intense study of Descartes, Wallis, and others (Link) (Link). Yet, despite having “worked out the fluxional calculus tolerably completely” by 1666 (Link), Newton hesitated to publish his findings. Encouraged initially by mentors like Isaac Barrow and correspondent John Collins to share his new methods, Newton began preparing his results for publication – only to pull back. By 1672, after encountering criticism in other work, he “started to have doubts about the wisdom” of publishing his calculus (Link). This pattern of discovery followed by secrecy would characterize much of Newton’s mathematical career.
One striking feature of Newton’s unpublished work is how long he kept it hidden and how he sometimes encoded it to guard his priority. For example, Newton transitioned from infinite series to calculus in the late 1660s, but he revealed these advances only obliquely in correspondence. In 1676, he sent letters to Gottfried Wilhelm Leibniz (via the Royal Society’s Henry Oldenburg) hinting at his calculus. Newton “listed many of [his] results but did not describe his methods” (Link). He even embedded his discovery in cryptic anagrams rather than plain explanation (Link). By his own admission, Newton “wrapped the discovery of the calculus in a cryptogram” when communicating with Leibniz (Link). He recorded Latin anagrams in his notebook to conceal the technique for fluxions and infinite series (Link) – revealing them only to those he deemed worthy or to establish precedence later. This cautious approach stemmed in part from Newton’s fear that openly disclosing his methods would invite misunderstanding or plagiarism. Indeed, Newton’s reluctance to publish his fluxions until much later created a time lag that contributed to the infamous Newton–Leibniz calculus dispute. Newton’s “method of fluxions” treatise was written in 1671, but he “failed to get it published” and it did not appear in print until 1736 (Link). This decades-long secrecy allowed Leibniz to publish his own calculus first (in 1684), setting the stage for a bitter priority quarrel.
Despite remaining mostly secret during Newton’s lifetime, his private mathematical work did not stay entirely unknown. Through letters and manuscripts circulated among a small network, Newton’s advances “scarcely remained a secret” (Link) (Link). Other scholars of the era learned of some of Newton’s results – for instance, his generalized binomial theorem for fractional exponents (discovered around 1665) was shared in a 1676 letter – but they often lacked Newton’s full proofs or methods. Newton intentionally left certain derivations “obscure” to outsiders. For example, in his magnum opus Principia Mathematica (1687), Newton chose to present proofs geometrically, avoiding explicit calculus notation. While calculus concepts are implicit throughout Principia, Newton likely omitted his fluxional calculus in print to make the work more accessible and to avert potential controversy (Link) (Link). By sticking to classical geometry, Newton kept the novel calculus techniques “behind the scenes,” partly to forestall objections that might arise from introducing a new mathematical language (Link).
Only in the early 18th century did Newton begin to allow publication of his long-held mathematical inventions. In 1704 – nearly 40 years after he first discovered calculus – Newton appended two treatises to the Opticks that finally revealed some of his hidden math. In De Quadratura Curvarum (“On the Quadrature of Curves”), he published his method of fluxions and applications of infinite series (Link). This tract included, for example, the first published statement of the general binomial theorem and what is now known as Taylor’s series expansion (Link). Likewise, in the companion piece Enumeratio Linearum Tertii Ordinis he published his extensive classification of cubic curves, a topic he had studied decades prior. Newton had determined by the late 1670s that there are 72 “species” of cubic curves (grouped into several genera), an accomplishment only published in this 1704 appendix long after the work was done (Link) (Link). Similarly, Newton’s treatise on algebra, Arithmetica Universalis, was based on lectures from the 1670s and early 1680s but remained “doomed to college confinement,” as an editor put it, until 1707 (Link) (Link). Newton’s successor William Whiston took the initiative to edit and publish this work without Newton’s immediate approval. Newton initially opposed publishing the Arithmetica, and only later “reluctantly” agreed to its release (Link). The preface by Whiston justified bringing this “noble and useful Work” to the public after Newton had left it in manuscript for ~30 years (Link). These examples show a clear pattern: Newton often moved on to new ideas and left major results unpublished for years, either out of perfectionism, fear of being misunderstood, or lack of interest in public acclaim. When his private mathematical manuscripts eventually came to light, they revealed that Newton had quietly anticipated or exceeded many developments that later mathematicians published as new. The transition from one idea to another in Newton’s notebooks – from series to fluxions, from algebra to geometry – appears as a continuous, almost compulsive exploration. Yet outwardly Newton kept these transitions hidden, disclosing only polished fragments. In some cases, he even coded or obscured his insights (using anagrams or classical geometric form) specifically to prevent misuse or controversy. Newton’s contemporaries thus saw only the tip of the iceberg of his mathematical genius, while the fuller synthesis remained locked in his drawers until after his death.
(File:GodfreyKneller-IsaacNewton-1689.jpg - Wikipedia) Fig. Sir Isaac Newton in 1689, aged 46 (portrait by Sir Godfrey Kneller). Newton’s brilliance was matched by a secretive, cautious nature that kept many of his mathematical discoveries hidden for decades.
Psychological and Biographical Influences
Newton’s guarded approach to publishing and his intellectual trajectory cannot be separated from his unusual personality and life experiences. Biographical evidence suggests that Newton’s solitary habits, emotional insecurities, and tumultuous relationships deeply influenced how and what he chose to study – and what he chose to conceal. From childhood, Newton experienced emotional turbulence that shaped his inner life. He was born in 1642 after his father’s death, and at age three his mother Hannah left him in the care of his grandparents for years, while she remarried. Newton did not live with his mother again until he was about 10 years old (Link) (Link). This early separation left psychological scars. As one commentator notes, “Newton’s mother [was] away from him… One might imagine that such an act could breed bitterness” toward his mother and stepfather, a clergyman (Link). Indeed, a young Newton harbored anger – he later recorded in a private list of sins a wish to “burn [my stepfather] and the house over him”. Yet Newton also sought refuge in an inner world of study and contemplation, perhaps as compensation for childhood loneliness. Some historians have even suggested that Newton’s lifelong quest for absolute truth (especially knowledge of God) was, in a Freudian sense, a substitution for the absent parental love (Link). Whether or not one accepts that interpretation, it is clear that Newton’s early isolation bred in him a fierce independence and self-reliance. He learned to occupy himself with ideas rather than people, spending his youth building mechanical models and devouring books in solitude (Link) (Link). This upbringing primed Newton to become a solitary thinker – intensely focused, but also socially withdrawn and emotionally guarded.
As Newton grew into adulthood and launched his academic career at Cambridge, his sense of isolation and hypersensitivity to criticism became more pronounced. Newton was, by many accounts, an extremely introverted and anxious individual. He had few close friends and showed little interest in socializing beyond a small circle. Contemporary observers described him as obsessive and guarded. William Whiston, who succeeded Newton as Lucasian Professor, recalled Newton as “of the most fearful, cautious and suspicious temper that I ever knew” (Link). John Maynard Keynes, after studying Newton’s papers, similarly concluded that Newton had a “profound shrinking from the world, a paralyzing fear of exposing his thoughts… to the inspection and criticism of the world” (Link). This psychological aversion to scrutiny explains much of Newton’s reluctance to publish. Newton simply dreaded the prospect of others attacking or misinterpreting his ideas. Indeed, when he did publish early on – for example, his first papers on optics in 1672 – the critical responses distressed him greatly. After Robert Hooke and others questioned his experiments with light, Newton became defensive and upset. The experience was bitter enough that Newton withdrew from public scientific debate for several years (Link) (Link). “I see I have made myself a slave to philosophy,” he complained in a 1676 letter amidst these disputes, “but if I get free of it, I will resolutely bid adieu to it eternally” (Link) (Link). In the same letter Newton lamented that one must either share nothing new or be “a slave to defend it” against critics (Link). This reveals how personal and raw Newton’s feelings were – criticism did not roll off his back, but instead struck at his very sense of self. His instinctive solution was to retreat and guard his work more closely (as seen in his decades-long delay in releasing the calculus). Newton’s deteriorating relationship with Leibniz over the calculus reflects this mindset as well. Initially, in the 1670s, Newton corresponded cordially with Leibniz, sharing some results. But as soon as Newton felt his priority was threatened – suspecting Leibniz might claim or misuse his method – Newton became suspicious and resentful (Link). By the early 1700s, that collegial friendship had soured into open enmity. Newton secretly orchestrated the Royal Society’s 1713 report Commercium Epistolicum that accused Leibniz of plagiarism (Link). This episode shows Newton’s extreme defensiveness: he would go to great lengths to protect his intellectual property and reputation, even if it meant harming an erstwhile friend. Psychologically, Newton seemed to interpret criticism or rivalry not just as scholarly discourse but as personal attacks – threats to the almost sacred mission he believed he was pursuing.
Key life events further shaped Newton’s intellectual development and reinforced his reclusive tendencies. In 1665–1666, an outbreak of plague forced Newton to leave Cambridge and work alone at his family home in Woolsthorpe. This seclusion coincided with Newton’s “annus mirabilis,” a period of feverish discovery where, free from lectures or peers, he conceived of calculus, discovered the laws of motion and gravitation, and advanced optics. The success of solitary work likely confirmed to Newton the value of isolation. Conversely, later events taught him that engagement with others could be troublesome. His notorious feud with Robert Hooke in the 1670s (over Newton’s prism experiments and theories of light) traumatized Newton. After heated exchanges, Newton essentially quit publishing on optics until after Hooke’s death. He buried himself in other studies at Cambridge rather than face more public controversy (Link) (Link). Another blow came in the early 1690s: in 1689 Newton’s mother (with whom he had reconciled and grown close) died, and a few years later in 1692–1693 Newton appears to have suffered a nervous breakdown (Link) (Link). He endured insomnia, depression, and paranoia during this time, writing strange, distraught letters to friends Samuel Pepys and John Locke that made colleagues fear for his sanity (Link). Newton spoke of having “lost the former consistency of [his] mind” (Link). The causes of Newton’s breakdown are debated – possibly chemical poisoning from alchemical experiments, or emotional distress over the departure of his closest friend and collaborator of the time, Nicolas Fatio de Duillier. Regardless, the episode marked a turning point: Newton never again produced science with the same single-minded intensity as in his youth (Link). Shortly afterward, he left academia for a government post (Master of the Mint in 1696). He also became more publicly involved – serving as President of the Royal Society from 1703 – yet these roles were administrative, and Newton remained personally aloof and authoritative. If anything, age and authority made Newton even less tolerant of dissent. In the calculus priority battle and other disputes, Newton used his stature to dominate opponents (for instance, he dismissed Leibniz’s supporters and refused to debate directly, saying he “will not reply to an idiot” in one instance (Link)).
Throughout his life, Newton also possessed a profound religious devotion and sense of destiny that influenced his intellectual choices. Privately, Newton was a deeply spiritual man, convinced that God had chosen him for a special mission. He believed he was “specially chosen by God to protect the original, pure form of Christianity”, considering this his most important work (Link). This conviction stemmed from Newton’s heterodox religious views: he was a devout Christian but rejected certain doctrines (like the Trinity) and was determined to restore what he saw as true biblical religion. The feeling of divine calling made Newton fiercely determined in his studies but also secretive – since his beliefs were unorthodox, he mostly kept them hidden to avoid censure. Biographers note that Newton “believed that he had been chosen by God to discover the truth about the decline of Christianity” and that this was “by far the most important” task of his life, greater even than his scientific work (Link). Consequently, Newton poured enormous effort into theology and scriptural study (as much as, if not more than, into physics), but he shared those findings only with trusted confidants. He feared misunderstanding not only of his math, but of his religious ideas, which could brand him a heretic if revealed. Newton’s almost messianic self-conception also influenced how he responded to criticism. He saw attacks on his ideas as attacks on truth (and by extension, on God’s work). Thus, any opposition – whether Hooke belittling his optics or Leibniz contesting calculus – Newton viewed as something to be quashed in service of a higher mission. In his mind, he wasn’t merely protecting his ego; he was defending divinely inspired knowledge. This helps explain the ferocity with which Newton carried out disputes. It also explains why Newton could not tolerate errors in his work: perfectionism was part of his personality, but also, he believed Truth was at stake. For Newton, personal experiences (loneliness, conflict, faith) all wove into an identity as a chosen instrument of God uncovering the hidden laws of the universe. His isolation and secrecy were as much strategic (to avoid external interference) as they were emotional (to avoid getting hurt). The net result was an intellectual giant who produced revolutionary ideas in private, safeguarded them until he felt the world was ready (or he was forced by circumstances), and only selectively engaged with the scientific community – all of which traces back to the influences of his extraordinary life story.
Theological and Mystical Underpinnings
While Newton publicly built the foundation of classical physics, he privately immersed himself in theology, Biblical prophecy, and alchemy. These theological and mystical pursuits were not mere side hobbies but central to Newton’s worldview – and they influenced his scientific thinking in subtle ways. Newton saw the universe as an integrated whole governed by divine laws, and he believed clues to those laws could be found not only in nature (through mathematics and experiment) but also in the Bible and ancient wisdom traditions. He was, as Keynes famously described, “the last of the magicians”, viewing reality as a grand cryptogram set by the Almighty (Link) (Link). To Newton, unraveling the secrets of calculus or gravity was part of the same divine puzzle as decoding the symbols of prophecy or the alchemical transmutation of metals.
A major focus of Newton’s later years was Biblical prophecy and chronology. He approached the books of Daniel, Revelation, and other prophetic scriptures with the same rigor he applied to mathematics. Believing that God’s plan for history was knowable, Newton spent decades attempting to reconcile the prophetic visions of Daniel and the Apocalypse (Revelation) and to construct a timeline of world events. In 1704, Newton penned a confidential manuscript where he famously calculated that the world would not end before the year 2060 (Link). (Importantly, he added that he did not state this date dogmatically, but “to put a stop to the rash conjectures” of others about the end of days (Link).) Newton poured over Biblical texts in Hebrew and Greek, cross-referencing them with historical records. He even learned enough Hebrew to produce his own translation of the Book of Ezekiel so he could accurately grasp its details about the Temple of Solomon (Link). One of Newton’s most intriguing theological studies was the Temple of Solomon – he believed the architecture of the ancient temple held encoded wisdom about the cosmos and God’s plan. Newton devoted an entire chapter of his posthumously published Chronology of Ancient Kingdoms Amended (1728) to the Temple, complete with elaborate diagrams (Link). He hypothesized that the temple’s geometry and measurements were deliberately designed by King Solomon (under divine guidance) to embody a timeline of sacred history (Link). In other words, the structure itself was a cryptogram from God. Newton argued that many ancient structures and myths carried this kind of hidden meaning – an idea related to the Renaissance concept of prisca sapientia (“ancient wisdom”). He believed that wisdom given by God to figures like Adam, Noah, or Moses had been passed down in coded forms through architecture, symbols, and its preservation was the task of scholars to decipher (Link) (Link). “These men had hidden their knowledge in a complex code of symbolic and mathematical language that, when deciphered, would reveal unknown knowledge of how nature works,” Newton concluded (Link). Here we see a direct intersection of Newton’s theology and mathematics: he literally applied mathematical reasoning to decode scripture and saw numerical or geometric patterns as the key. Newton even described his interpretative method for prophecy as akin to a scientific analysis, aiming for simplicity and consistency. In a manuscript outlining his approach, Newton wrote: “It is the perfection of God’s works that they are all done with the greatest simplicity. He is the God of order and not of confusion. Therefore, as they that would understand the frame of the world must endeavor to reduce their knowledge to all possible simplicity, so it must be in seeking to understand [prophetic] visions.” (Link) (Link). He insisted on clear rules for interpreting the figurative language of prophecy, almost the way one would set axioms in math (Link) (Link). Newton claimed to show that every major historical event corresponded exactly to a prophetic symbol, boasting that his method “had totally exhausted the possible meanings” of the symbols in Revelation (Link). In short, Newton treated prophecy like a complex equation to be solved, yielding a consistent model of past and future events.
Newton’s religious and mystical studies not only ran in parallel to his scientific work but at times directly influenced it. For example, Newton’s deep conviction that God’s design is orderly and simple reinforced his drive to find unified principles in nature. His theological view of God as rational and not arbitrary gave Newton confidence that phenomena like planetary motions or optics could be explained by simple mathematical laws – a faith that underpinned his scientific breakthroughs. Conversely, Newton’s scientific discoveries sometimes fed into his theology. His understanding of orbits and astronomy informed his attempts at chronology. In his Chronology manuscript, Newton tried to date events like the Argonauts’ voyage and King Solomon’s reign by using astronomical phenomena (such as the precession of the equinoxes or recorded eclipses) (Link). He believed that by knowing the laws of celestial mechanics (thanks to his Principia work) he could more accurately work out ancient dates, thereby aligning secular history with Biblical history (Link). Newton’s work on alchemy – which he pursued vigorously in the 1670s and 1680s – also influenced his scientific imagination. Alchemy (or “chymistry” as Newton called it) was the medieval forerunner of chemistry, mixed with mystical ideas of transforming matter. Newton conducted hundreds of alchemical experiments in secret, writing down recipes and observations in coded language. He approached alchemical texts, which were famously obscure, as puzzles to be solved (much as he did biblical symbols) (Link). The alchemists’ notion of hidden forces and transformations in matter may have primed Newton to consider physical forces that act invisibly – such as gravity. Notably, Newton’s idea that a subtle “active principle” pervades matter (mentioned in queries of the Opticks) has an alchemical flavor. He speculated about an ethereal medium or spirit that might cause gravitational attraction and other phenomena, which shows a blending of his mystical and scientific thought. While Newton kept his alchemical research strictly secret (fearing ridicule or theological condemnation), it occupied a tremendous amount of his time. He collected and wrote over a million words on alchemy and arcane chemistry. This labor stemmed from his belief that God’s laws of nature might be learned from the ancients who concealed them in alchemical allegories. In Newton’s view, all knowledge was unified – the Bible, the works of the ancients, and the natural world were three different witnesses to the same truths. Thus, we find him cross-referencing insights from one domain to another. For instance, Newton’s study of the Temple of Solomon combined architectural measurements, scriptural exegesis, and geometric analysis – blurring the line between science and symbolism (Link). He was, as one biographer put it, “enlarging the bounds of moral philosophy” by applying scientific rigor to spiritual questions and vice versa. Newton’s contemporaries saw only pieces of this grand intellectual mosaic. To the public, he was the great mathematician and physicist; but privately, he was equally a theologian and alchemist searching for hidden unity. His belief that “the universe [is] a cryptogram set by the Almighty” meant that whether he was studying a comet’s motion or an apocalyptic vision, he felt he was deciphering God’s code (Link). This unifying conviction drove Newton to brilliance in science and to profound, if unorthodox, conclusions in religion – each endeavor feeding the other with metaphors and insights. Today, scholars recognize that Newton’s scientific revolution cannot be fully understood without acknowledging the theological and mystical underpinnings that guided his quest for knowledge.
Timeline: Newton’s Intellectual Progression and Hidden Work
1642–1661: Early Life and Education – Isaac Newton is born on December 25, 1642 (OS) in Woolsthorpe, Lincolnshire. His father dies before his birth; at age 3 his mother leaves to remarry, an emotional trauma that instills in Newton a sense of isolation (Link). A quiet, inquisitive child, Newton prefers reading and tinkering alone. In 1661 he enters Trinity College, Cambridge. Initially an average student, Newton discovers his passion for mathematics around 1663–64 after reading works by Descartes and others (Link) (Link). He keeps a “Waste Book” notebook where he methodically teaches himself geometry and algebra, quickly surpassing the curriculum.
1664–1666: “Annus Mirabilis” – Discoveries in Private – Free from routine due to the 1665–66 plague closure of Cambridge, Newton returns to Woolsthorpe and experiences an incredible creative burst. In these two years (at ages 22–24) he lays the groundwork for calculus, formulating his fluxion notation and the binomial series expansion (Link) (Link). He also experiments with optics (investigating the spectrum of sunlight with prisms) and conceives the law of universal gravitation – famously pondering that the force pulling an apple to Earth might also govern the Moon’s orbit (Link). Newton later recollects that during this period he “in Mathematics purged himself of ignorance”, solving problems that had stumped others. Notably, Newton keeps these breakthroughs largely to himself, recording them in notebooks but not publishing. The first documentary proof of his calculus is a manuscript of May 1665 (Link). By late 1666, Newton has also considered the inverse-square law of gravity’s effect on planetary motion (though an exact calculation must wait). This flurry of unpublished genius in 1665–66 sets the stage for all his future work.
1667–1671: Early Career at Cambridge – Newton returns to Cambridge in 1667 as a Fellow of Trinity. In 1669, at just 26, he is appointed Lucasian Professor of Mathematics (succeeding Isaac Barrow). Newton begins lecturing – his topics include optics and algebra – and further develops his ideas. Importantly, in 1669 he anonymously shares a manuscript De Analysi on infinite series with a few scholars (via Barrow and John Collins), marking the first private dissemination of his calculus results (Link). He also works on a comprehensive text on fluxions (written in 1671) and an essay on the methods of series, though these remain unpublished. Newton’s lectures on algebra will form the basis of Arithmetica Universalis. Meanwhile, Newton’s interest in theology and alchemy is sparked. Around 1669–1670, concerned about the requirement to take holy orders for his professorship, Newton starts an intensive study of religion – especially the doctrine of the Trinity, which he comes to doubt (Link). This leads him into clandestine theological research. Simultaneously, he purchases chemical apparatus and begins alchemical experiments in his private laboratory (Link). By the early 1670s, Newton’s life is a blend of advanced mathematics, optical research, nightly alchemy sessions, and biblical study – much of which he keeps secret.
1672–1678: First Publications and Retreat – Newton makes his public debut in 1672, sending the Royal Society an account of his new reflecting telescope and a paper on the “new theory about light and colors.” He is elected a Fellow of the Royal Society. However, the ensuing correspondence – criticisms from Robert Hooke (who challenges Newton’s claims about colors) and others like Huygens – frustrates Newton (Link). He engages in heated exchanges for a few years. By 1675, a weary Newton vows to avoid further controversy. He writes to Oldenburg, “I see I have made myself a slave to philosophy… I will resolutely bid adieu to it eternally, excepting what I do for my private satisfaction” (Link) (Link). True to his word, Newton withdraws from publication. He declines to print any more on optics (holding off publishing his full Opticks until 1704) and he withholds his calculus. In 1675–76, instead of printing his mathematical discoveries, Newton opts to share them via letters. He corresponds with Leibniz, hinting at his calculus by describing methods in cryptic form (including the famous anagram accusatio message) (Link). Newton likely fears his innovative math would be misunderstood, so he shares it only cautiously. During the late 1670s, Newton devotes much time to alchemy – attempting to decode alchemical texts and conducting experiments. He also writes papers on motion and gravitation privately. In 1679, Newton’s longtime absence from active science is broken when Hooke writes to him about planetary motion problems. Newton initially provides a solution (deriving that an inverse-square force yields elliptical orbits) but then lapses into silence again (Link) (Link). Notably, 1679 is also the year Newton’s mother dies, which brings him emotional grief and briefly interrupts his isolation at Cambridge (Link).
1684–1687: The Principia and Peak of Fame – In 1684, Edmond Halley’s visit to Cambridge re-engages Newton with natural philosophy. Halley inquires about orbital dynamics, and Newton famously answers that planets follow ellipses under an inverse-square attraction – a result he says he already “found” years prior (Link). When Newton’s old papers cannot be located, he quickly produces a fresh proof (De Motu Corporum in Gyrum). Encouraged by Halley, Newton then embarks on writing his great treatise. Over an intense 18-month period (1685–1686), working largely alone, Newton expands his short tract into Philosophiæ Naturalis Principia Mathematica. This work, published in 1687 with Halley’s support, mathematically formulates the laws of motion and universal gravitation. The Principia instantly elevates Newton’s standing across Europe. However, even in the Principia, Newton’s secretive style persists: he deliberately uses classical geometric proofs, avoiding direct mention of fluxions/calculus (Link). He privately employs calculus to derive results but does not showcase the method, partly to make the work accessible and perhaps to sidestep any credit to Leibniz (Link). A controversy with Hooke also erupts over the inverse-square law (Hooke claimed priority for the idea). Newton, in the Principia, initially omitted acknowledging Hooke, then added a vague credit in later editions – reflecting their strained relations. By 1687, Newton is at the pinnacle of scientific achievement, yet he remains a somewhat reluctant public figure. After the Principia, he produces no further major scientific publications for the rest of his life, turning his attention elsewhere.
1687–1696: Transition – London, Public Life, and Esoteric Studies – The late 1680s bring changes in Newton’s life. With England’s political turmoil (the Glorious Revolution), Newton becomes briefly involved in politics, serving as Cambridge’s representative to the Convention Parliament (1689). In London, he socializes with John Locke and others, a rare period of relative sociability for him. However, Newton’s personal life remains turbulent. Around 1692–93, he endures a severe mental and emotional crisis (possibly related to overwork, chemical poisoning, or the loss of his close friend Fatio). After recovering, Newton seems disillusioned with academia. In 1696 he accepts an appointment as Warden of the Royal Mint (later Master of the Mint) and moves to London permanently. This marks the end of his Cambridge isolation. Professionally, Newton now focuses on reforming the coinage and other practical matters – tasks he performs with great diligence. Yet even as he enters public service, Newton pursues his theological research quietly in the background. In the 1690s he writes extensive notes on prophecy and Church history. Notably, around 1690 he pens a treatise “An Historical Account of Two Notable Corruptions of Scripture,” arguing that certain Biblical passages were doctored to support the Trinity. Aware of its explosive implications, Newton shows this treatise only to a few (like Locke) and never publishes it in his lifetime. By the end of the 1690s, Newton has compiled large manuscripts on Daniel and Revelation, formulated a chronology of ancient kingdoms, and continued alchemical experiments – all unpublished. He likely views this body of work as a fulfillment of his divine mission, but also as something the world is not ready to see.
1700–1710: President of the Royal Society and The Calculus Controversy – In 1703, Newton is elected President of the Royal Society, a position he will hold until his death. Now in his 60s, Sir Isaac Newton enjoys unparalleled prestige. He uses this clout to steer the direction of British science – and to defend his legacy. In 1704, with Robert Hooke now deceased, Newton finally publishes his comprehensive study of light, Opticks. This work also contains two appended mathematical papers (Quadratura and Enumeratio) that at last unveil some of Newton’s early mathematical inventions (Link). The choice to include these hints at Newton’s desire to assert his precedence in calculus as whispers of Leibniz’s accomplishments grow. By 1708–1710, the simmering Newton–Leibniz dispute boils over. Accusations fly on both sides about who invented calculus first. Newton, leveraging his role as Royal Society president, backs his claim with evidence from old letters and his Waste Book (which recorded dates proving his early work) (Link) (Link). In 1711, the Royal Society convenes a committee – effectively controlled by Newton – to investigate. The result is the 1713 report Commercium Epistolicum, which (unsurprisingly) credits Newton and implies Leibniz copied him (Link). Newton even anonymously wrote large parts of this report himself (Link). The controversy strains Newton’s and Leibniz’s relationship irreparably; they cease direct communication. During this decade, Newton also consents (reluctantly) to the publication of his earlier mathematical works like Arithmetica Universalis (1707) (Link). In 1706, an edition of Newton’s Method of Fluxions (in English translation) is prepared, though it only appears in print in 1736 after Newton’s death (Link). Thus, by 1710, virtually all of Newton’s once-unpublished math has either been published or at least documented in the calculus priority battle. Newton’s attention, meanwhile, is increasingly on revisiting his masterworks (he prepares new editions of the Principia and Opticks) and on polishing his theological writings for posterity.
1711–1727: Final Years and Posthumous Publications – In his last years, Newton continues to preside over the Royal Society, mentor younger scientists, and refine his past works. He publishes the second edition of Principia in 1713 (with an important General Scholium where Newton discusses God’s role in the cosmos) and a third edition in 1726. Throughout the 1710s and 1720s, Newton quietly works on his Biblical scholarship. He corresponds with scholars in Europe about chronology and prophecy (for example, discussing the date of the Apocalypse or the return of the Jews to Israel, based on his studies (Link)). Newton consolidates his notes into full treatises: Observations upon the Prophecies of Daniel and the Apocalypse and The Chronology of Ancient Kingdoms. He does not publish these, likely due to fear of backlash or the desire to avoid distractions. After Newton dies in March 1727, his heirs find an enormous mass of unpublished papers on theology and alchemy. In 1733, Observations on Daniel and Revelation is finally published (anonymously, though Newton’s authorship was known). In 1728, Chronology of Ancient Kingdoms is published. These reveal to the world a completely different Newton – one deeply engaged in biblical prophecy, who calculated that the Kingdom of God would be established perhaps in the mid-21st century (Newton’s 2060 prediction). They also show Newton’s attempt to unify knowledge: for instance, the Chronology includes appendices with his diagrams of Solomon’s Temple, linking architecture, scripture, and astronomy (Link) (Link). Over the subsequent centuries, more of Newton’s manuscripts (especially on alchemy) came to light, shocking historians who had long painted Newton as a paragon of rationalism. Only with the publication of Newton’s unpublished papers in the 20th century did it become clear how interwoven his scientific thought was with his mystical and religious pursuits (Link) (Link). Modern scholarship now sees Newton’s life as an extraordinary intellectual journey: from a lonely boy seeking solace in scripture and nature, to a young mathematician unlocking secrets of calculus in coded notebooks, to the triumphant author of the Principia, and finally to an elder scholar consumed by the desire to know God’s hidden plans. Each phase fed the next, with Newton’s unpublished work often acting as the bridge. His private calculus fed into the Principia, his private theology sustained him after the Principia. Newton’s evolution was thus not a simple linear path but a rich tapestry, with threads of mathematics, physics, theology, and alchemy all running concurrently. In the end, Newton saw himself as a servant of Truth in all its forms. As he famously remarked late in life, “I do not know what I may seem to the world, but as to myself I seem to have been only like a boy playing on the seashore… whilst the great ocean of truth lay all undiscovered before me.” He had charted more of that ocean in secret than anyone of his age could fathom. Only by examining his unpublished mathematics and his innermost intellectual passions can we appreciate the full scope of Newton’s genius and the profound influences that guided it.
References: Newton’s private notebooks and letters (as compiled in digital projects and edited volumes) provide key insights into his hidden work and mindset (Newton Papers : Newton's Waste Book) (Newton Papers : Newton's Waste Book). Modern analyses by historians like Richard Westfall, John Maynard Keynes, and Rob Iliffe have reinterpreted Newton’s life, emphasizing the unity of his scientific and mystical pursuits ( John Maynard Keynes: "Newton, the Man" - MacTutor History of Mathematics ) (Rosalind W. Picard) (Newton: A Very Short Introduction - Rob Iliffe - Google Books). The Cambridge Digital Library’s collection of Newton’s manuscripts and the Newton Project at Oxford have made many of these primary sources accessible, shedding light on Newton’s development of calculus (Isaac Newton (1642 - 1727)), his decision to withhold publication (Newton Papers : Newton's Waste Book), and his esoteric studies (Isaac Newton's occult studies - Wikipedia) (Isaac Newton's occult studies - Wikipedia). Newton’s Principia and Opticks remain as his public legacy, but it is his posthumously revealed papers – on topics from the mathematics of series to the measurement of King Solomon’s Temple – that complete the portrait of Newton as “one of God’s chosen few” (One of God's chosen few | Newton - Oxford Academic), a man whose intellect spanned both the heavens and the scriptures. Newton’s story is a powerful reminder that great ideas do not arise in isolation from personal context; rather, they are deeply embedded in the experiences, fears, and hopes of their creator. Newton’s unpublished work, coupled with a psychological and intellectual analysis of his influences, allows us to see Newton as he saw himself: an instrument of Providence uncovering the fundamental order that links the mathematical, natural, and divine realms.
