Isaac Newton

Isaac Newton (1642—1727) never practised medicine and wrote no medical treatise, yet his influence on the history of medicine was enormous and persistent. His Principia and Opticks provided the intellectual model that eighteenth-century physicians tried to reproduce: a small number of mathematical laws governing the behaviour of matter. The attempt to build a Newtonian medicine — reducing the body to particles obeying laws of motion through tubes of various diameters — dominated the first half of the eighteenth century and shaped the careers of Boerhaave, Pitcairne, and their students. Newton also appears, less expectedly, as a dedicated alchemist whose private pursuit of chrysopoeia connected him to Robert Boyle and John Locke in a network of chymical exchange.

Newton and the Mechanical Philosophy

The fundamental shift of early modern science, as Driesch identified it, was the adoption of quantitative and analytic thought about natural processes, combined with the concept of natural law (Driesch, 1914). Galileo exemplified the beginning of this shift, while both Descartes and Leibniz adopted a mechanistic view of life, holding that nature as a whole, including physical processes, was a mechanical system arranged by God, while maintaining soul-body dualism only for the spiritual realm (Driesch, 1914).

In The Structure of Scientific Revolutions (1962), Kuhn identifies Newton alongside Copernicus, Lavoisier, and Einstein as the canonical instances of scientific revolution, each requiring the community’s rejection of one time-honored theory in favor of another incompatible with it (Kuhn, 1962). The Principia and Opticks functioned as paradigms in Kuhn’s technical sense: they defined legitimate problems and methods for succeeding generations of researchers, achieving their status not by being exhaustive but by being more successful than competitors in solving a few acute problems (Kuhn, 1962) (Kuhn, 1962). Before Newton’s optics, there was no single accepted view of the nature of light; competing schools derived from Epicurean, Aristotelian, or Platonic theory, each emphasizing different phenomena (Kuhn, 1962). Newton’s theory of light originated in the discovery that none of the existing pre-paradigm theories could account for the length of the spectrum (Kuhn, 1962). His 1672 paper in the Philosophical Transactions, one of the first papers in that journal to employ the genre of experimental narrative, argued that different colours of light correspond to different degrees of refrangibility, making colour an intrinsic and unalterable property of each ray rather than a modification of white light. (Peter Dear, 2001) (Peter Dear, 2001)

Yet Kuhn also notes that scientists who agreed in identifying Newton’s work as paradigmatic did not necessarily agree on any full interpretation of it. As Kuhn observes, “scientists can agree that a Newton, Lavoisier, Maxwell, or Einstein has produced an apparently permanent solution to a group of outstanding problems and still disagree, sometimes without being aware of it, about the particular abstract characteristics that make those solutions permanent”, lack of a standard interpretation does not prevent a paradigm from guiding research (Kuhn, 1962). This is precisely what happened with Newtonianism in medicine: Pitcairne, Boerhaave, and the Montpellier vitalists all claimed to follow Newton while reaching mutually incompatible conclusions about the nature of the body.

Helmontian Medicine and the Context Newton Displaced

Before the full programme of Newtonian medicine took hold, a transitional tradition occupied the intellectual space between Galenic orthodoxy and the mechanical philosophy. Wear shows that Helmontian medicine stood midway between Paracelsianism and the “new science” of Galileo, Descartes, Boyle, and Newton: it employed vitalistic chemical principles while being less tainted by magical associations than Paracelsian practice and more rigorous in its experimental methods (Wear, 2000). By the mid-seventeenth century, Helmontianism posed the most serious alternative to Galenic therapeutics. Newton’s emergence and the subsequent programme of iatromechanism drew partly on this Helmontian inheritance even as they displaced it: Boyle’s corpuscular chemistry, which fed directly into iatromechanical theory, was itself shaped by debate with Helmontian practitioners.

Newtonian Medicine

The most direct medical consequence of Newton’s work was the attempt by a group of Scottish and English physicians to construct a medicine on Newtonian principles. French’s analysis identifies Archibald Pitcairne and his followers as the architects of “the principles of mathematical theoretical medicine,” derived partly from the atomism of Newton’s essay on the nature of acids and partly from the queries added to the 1706 edition of the Opticks (French, 2003). The programme aimed to restore mathematical certainty to medicine after the collapse of traditional natural philosophy.

Boerhaave, the most influential physician of the early eighteenth century, built his physiological system on Newtonian mechanics. He postulated a series of vessel orders of decreasing diameter — sanguiferous, serous, and lymphatic — each carrying progressively smaller humoral particles, forming a hydraulic system in which particles of differing mass obeyed laws of motion through tubes of various diameters (King, 1958). Pitcairne’s inaugural address of 1692 advocated attending only to the observable properties (vires) of medications and disease rather than hidden physical causes — a self-consciously Newtonian methodological stance, though King notes Pitcairne failed to follow his own principles in practice (King, 1978).

Newton as Alchemist

When Newton’s alchemical papers were auctioned at Sotheby’s in 1936, John Maynard Keynes read through them and declared that Newton was “not the first of the age of reason but the last of the magicians.” Keynes’s remark crystallizes the biographical irony that Newton spent more time on alchemy and occult researches than on the experimental and mathematical physics for which he became canonical. (Bortoft, Henri, 1996)

Principe’s The Aspiring Adept (1998) reveals a Newton far removed from the public image of the austere mathematician. Betty Jo Teeter Dobbs’s work on Newton’s alchemy had already paved the way for reexamining alchemy’s role among major figures of the Scientific Revolution (Principe, 1998). Robert Boyle was deeply engaged in traditional alchemical practices including chrysopoeia, and his manuscripts contained not predominantly transcripts — as in Newton’s case — but considerable original material and laboratory accounts (Principe, 1998).

Boyle maintained an extensive alchemical network that included George Starkey, John Locke, and Newton himself. Boyle’s pursuit of the Philosophical Mercury lasted from his earliest experiments to his deathbed (Principe, 1998). Less than a month after Boyle’s death in 1691, Newton wrote to Locke: “I understand Mr. Boyle communicated his process about the red earth and mercury to you as well as to me” — evidence that Newton and Locke were both privy to Boyle’s most closely guarded chymical secrets (Principe, 1998).

Boyle’s Anti-Elixir tract (1678) [GAP: long puzzling to historians as an anomalous public disclosure from a notoriously secretive alchemist, connects this network to a specific biographical moment]. Principe argues that its publication was most likely the result of Boyle’s annus mirabilis alchemicus of 1677-78, when Boyle personally witnessed transmutations and received accounts of Wenzel Seyler’s transmutations, rather than being prompted by Newton’s private criticism (Principe, 1998). [GAP: The Anti-Elixir was in fact a fragment of Boyle’s larger Dialogue on the Transmutation and Melioration of Metals, reconstructed by Principe from twenty-three surviving manuscript fragments.] [GAP: This reconstruction situates Newton’s relationship with Boyle not as that of a skeptical mathematician tolerating a credulous friend, but as one adept among others in a shared pursuit that both men took entirely seriously.]

The Unity of Truth and the Vegetable Spirit

Dobbs’s The Janus Faces of Genius (1991) argues that Newton’s alchemy was not a peculiar hobby but an integral part of his intellectual programme.(Dobbs, Betty Jo Teeter, 1991) Dobbs traces Newton’s alchemical, religious, and cosmological thought through the interwoven problems of the microscopic spirit of alchemy and the cause of the cosmic principle of gravitation — a framing that already shows the book’s central argument. The intellectual context Dobbs establishes matters here: Western Europe had undergone an epistemological crisis across the sixteenth and seventeenth centuries, as competing philosophical systems multiplied and formal Pyrrhonist skepticism gave rigorous expression to a pervasive doubt about whether certain knowledge was attainable at all. Newton was emphatically not a skeptic, and Dobbs argues that his assumption of the unity of Truth functioned as a direct answer to this crisis (Dobbs, Betty Jo Teeter, 1991). Newton’s fundamental assumption was “the unity of Truth” — that true knowledge in any domain was ultimately knowledge of God, making natural philosophy, alchemy, prophecy, and mathematics complementary rather than competing paths to understanding.(Dobbs, Betty Jo Teeter, 1991) His methodology was correspondingly broader than the mathematical-experimental method moderns associate with Newtonian science: he marshaled “mathematics, experiment, observation, reason, revelation, historical record, myth, the tattered remnants of ancient wisdom” in pursuit of what Dobbs characterizes as “the knowledge of God.”(Dobbs, Betty Jo Teeter, 1991)

What Newton sought in alchemy was a “vegetative principle” — a secret, universal, animating spirit that he understood to be the force through which God constantly moulded the universe to providential design, “producing all manner of generations, resurrections, fermentations, and vegetation.” In short, it was the action of this active vegetative principle that kept the universe from being the sort of closed mechanical system for which Descartes had argued.(Dobbs, Betty Jo Teeter, 1991) Newton drew a fundamental distinction between “vegetable” and “mechanical” chemistry as early as the 1660s, identifying alchemy with the former, and this distinction persisted throughout his career.(Dobbs, Betty Jo Teeter, 1991)

This concern with active principles had direct consequences for Newton’s natural philosophy. Where Descartes built a system from passive matter and contact mechanics alone, Newton — following Henry More’s self-correcting epistemological procedure of balancing senses, reason, and revelation against one another — insisted that matter required non-mechanical forces to explain its behaviour.(Dobbs, Betty Jo Teeter, 1991) The gravitational attraction of the Principia, which continental critics denounced as occult, was in Dobbs’s reading the descendent of alchemical active principles: forces that acted on matter without being reducible to mechanical contact. Newton’s alchemical manuscripts, spanning four decades across institutions from King’s College Cambridge to the Jewish National Library in Jerusalem, document his sustained effort to locate and characterize these forces experimentally.(Dobbs, Betty Jo Teeter, 1991)

The consistency across Newton’s seemingly disparate pursuits — optics, mechanics, alchemy, prophecy, biblical chronology — lay not in any single natural-philosophical system but in his “overwhelming religious concern to establish the relationship between Creator and creation.” It was precisely where his different lines of investigation met, where he tried to synthesize their discrepancies into a more fundamental unity, that he achieved his greatest insights.(Dobbs, Betty Jo Teeter, 1991)

Newton’s Early Matter Theory and the Problem of Cohesion

During his student years Newton became an eclectic corpuscularian, drawing on Descartes, Gassendi (via Charleton), Boyle, Hobbes, Digby, and More, and recording his eclectic synthesis in the Questiones quaedam philosophicae of his student notebook.(Dobbs, Betty Jo Teeter, 1991) Like other mechanical philosophers of his day, he placed considerable faith in an all-pervasive mechanical aether — a subtle, imperceptible medium transmitting effects by pressure and impact — as the agent of both gravity and the cohesion of particles of matter.(Dobbs, Betty Jo Teeter, 1991) This early mechanical orthodoxy was, however, troubled from the outset by the problem of cohesion, which had plagued atomism since antiquity: the random, mechanical motion of small particles seemed intuitively unable to account for the organized coherence of living forms.(Dobbs, Betty Jo Teeter, 1991) Newton’s insistence on the inertial homogeneity and transformability of all matter — that all ultimate passive particles are alike — only intensified the theological problem; if all particles are fundamentally identical, how can they become organized into the immense variety of living beings by mechanical impact alone?(Dobbs, Betty Jo Teeter, 1991)

From Mechanical Aether to Alchemical Spirit: The 1660s and 1670s

Newton’s earliest theory of gravity, dating from around 1664, was entirely conventional impact physics — an orthodox mechanical aether theory with no hint of what gravity would become: an active principle dependent upon God’s will.(Dobbs, Betty Jo Teeter, 1991) Some five years later, in his “Propositions” of about 1669, the first active principle appeared in Newton’s papers, derived wholly from the alchemical tradition but stimulated by Neoplatonic critiques of Descartes’s mechanical system.(Dobbs, Betty Jo Teeter, 1991) The Cambridge Platonists Henry More and Ralph Cudworth had forced the issue: they argued that Cartesian mechanism was inadequate because passive matter alone could not perform providential design — spiritual intermediaries were required. Newton fully accepted this program, but rather than rest content with a philosophical statement, he turned to the study of alchemy to implement it experimentally, because alchemy not only discussed active principles but claimed to provide laboratory evidence of their operation.(Dobbs, Betty Jo Teeter, 1991)

Newton’s alchemical spirit of the 1660s, however, had elements of materiality — subtlety, mercuriality, volatility — that distinguished it from Henry More’s decisively incorporeal spirit of nature. Seventeenth-century “spirits” were notoriously ambiguous, existing in a gray area between solid matter and the Deity, capable of being either corporeal or incorporeal as required by the problem being explained.(Dobbs, Betty Jo Teeter, 1991) In the early 1670s Newton began to weave together his mechanical gravitational aether and the nonmechanical alchemical spirit by assuming that smaller material particles possess greater “spirituality” and activity — a Stoic and alchemical idea that allowed him to treat both functions within a single physical framework.(Dobbs, Betty Jo Teeter, 1991)

The intellectual sources Newton drew on here were broader than More and Cudworth alone. He owned Van Helmont’s Ortus medicinae in an edition including almost all his works and made manuscript notes on it; his use of fermentation as a principle of specification bears a resemblance to Van Helmont’s concept of the ferment as the differentiating agent of undifferentiated matter.(Dobbs, Betty Jo Teeter, 1991) He also possessed Leibniz’s Hypothesis physica nova of 1671, in which a divine aether penetrates and activates matter through fermentative processes — another possible channel connecting Helmontian vitalism to Newton’s own developing framework.(Dobbs, Betty Jo Teeter, 1991)

Newton’s “Vegetation” manuscript of the early 1670s shows this fusion in progress. The descending gravitational aether becomes “a tender ferment” interwoven with bodies and promoting their actions, while gravity remained nominally mechanical.(Dobbs, Betty Jo Teeter, 1991) In a striking animistic passage of the same manuscript, Newton described the earth as resembling “a great animal or rather inanimate vegetable” that draws in aethereal breath for daily refreshment and vital ferment — an animistic conception Dobbs traces to the Stoics.(Dobbs, Betty Jo Teeter, 1991) The Stoic distinction between a hidden creative fire (active, identified with the divine) and ordinary destructive fire closely parallels the alchemists’ concept of an occult fire, and Newton explicitly spoke of a “secret fire” in the same manuscript.(Dobbs, Betty Jo Teeter, 1991)

The Vegetation Manuscript (Dibner MSS 1031 B)

The manuscript “Of Nature’s obvious laws & processes in vegetation” (Dibner MSS 1031 B, ca. 1672) is the document Dobbs identifies as the single most important key to decoding the role of alchemy in Newton’s thought.(Dobbs, Betty Jo Teeter, 1991) It was sold at the 1936 Sotheby auction and rescued from the London Blitz by collector Bern Dibner; it now rests in the Dibner Library at the Smithsonian Institution.

The manuscript’s argument is systematic. Newton claims that metals “vegetate” by the same universal laws as plants and animals, governed by a latent spirit that “is y* same in all things only discriminated by its degrees of maturity & the rude matter.”(Dobbs, Betty Jo Teeter, 1991) Its central definition of the vegetable spirit is among the most explicit passages Newton ever wrote on the subject: the spirit is “Natures universall agent, her secret fire, the onely ferment & principle of all vegetation. The material soule of all matter w^{h} being constantly inspired from above pervades & concretes w^{h} it into one form & then if incited by a gentle heat actuates & enlivens it but so tender & subtile is it w^{h}all as to vanish at y* least excess.”(Dobbs, Betty Jo Teeter, 1991) The spirit is drawn “constantly inspired from above” — a cosmic rather than merely chemical agent.

The manuscript also distinguishes categorically between vegetable and mechanical actions: “Natures actions are either vegetable or purely mechanicall (grav. flux, meteors, vulg. Chymistry). The principles of her vegetable actions are noe other then the seeds or seminall vessels of things those are her onely agents, her fire, her soule, her life.”(Dobbs, Betty Jo Teeter, 1991) This division between vegetable and mechanical processes is not a curiosity of Newton’s early writing; it organizes his entire mature natural philosophy.

A theological section occupies the same manuscript, arguing that “The world might have been otherwise then it is (because there may be worlds otherwise framed then this) Twas therefore noe necessary but a voluntary & free determination y* it should bee thus. And such a voluntary determination implys a God.”(Dobbs, Betty Jo Teeter, 1991) Voluntarism and alchemy are written into a single document because they are parts of the same argument: if God freely chose the laws governing nature, those laws need not be mechanical, and alchemy’s claim to operate by non-mechanical active principles is therefore religiously defensible.

Newton also speculates in the same manuscript that “tis more probable y* aether is but a vehicle to some more active spt… y* a great pt if not all the moles of sensible matter is nothing but AEther congealed & interwoven into various textures whose life depends on that pt of it w^{h} is in a middl state.”(Dobbs, Betty Jo Teeter, 1991) This image of matter as congealed aether animated by a mediating portion anticipates the hierarchy of active and passive principles that structures the mature Opticks.

The 1675 Hypothesis and Newton’s Arian Turn

By 1675 Newton’s letter to the Royal Society — his “Hypothesis explaining the Properties of Light” — shows three notable shifts from the private “Vegetation” manuscript. The gravitational principle was further spiritualized: no longer the bulk of the aether but a special thin part of it, something especially subtle, similar to the vital spirit in air, was now responsible for gravitation.(Dobbs, Betty Jo Teeter, 1991) At the same time, the gravitational and vegetative functions were drawn even closer together, so that gravity itself had become in many ways an active principle bearing the life-giving properties of the vegetable spirit.(Dobbs, Betty Jo Teeter, 1991) Newton also, somewhat equivocally, extended his animistic earth-aether system to include the sun and planets — the sun imbibing this spirit copiously to conserve its shining and keep the planets from receding — a passage he later told Halley he had “interlined” as an afterthought.(Dobbs, Betty Jo Teeter, 1991)

The third shift in the 1675 Hypothesis reflects a revolution in Newton’s theological principles: his conversion to the Arian heresy during the early 1670s. Newton’s use of “protoplast” in the rare sense of “first agent” in the creative process — rather than its common meaning of “first prototype” — can only be read as an Arian interpretation, identifying the Christ-Logos with the cosmological intermediary who acts as first agent in creation.(Dobbs, Betty Jo Teeter, 1991)

Newton’s Voluntarist Theology

Newton became a convinced Arian during the first half of the 1670s, holding that the Son was the first created being and the intermediary through whom God created the world — a heretical position he carefully concealed in public but stated plainly in his private theological papers, which were unknown until examined after his death.(Dobbs, Betty Jo Teeter, 1991) His theology was equally shaped by voluntarism — the doctrine of potentia dei ordinata et absoluta — which held that natural laws represent God’s ordained power but that God retains absolute power to abrogate or alter them at will, making the world radically contingent upon divine decision rather than necessity.(Dobbs, Betty Jo Teeter, 1991) This theological framework had roots stretching back to the Condemnations of 1277, and guided many Scientific Revolution figures — Descartes, Gassendi, Boyle, and Charleton among them — in their inquiries into God’s relationship to nature.(Dobbs, Betty Jo Teeter, 1991)

Newton’s “Vegetation” manuscript contains an explicit statement of this voluntarist theology: “Whatever I can conceive without a contradiction, either is or may be made by something… The world might have been otherwise than it is (because there may be worlds otherwise framed than this). It was therefore no necessary but a voluntary and free determination that it should be thus.”(Dobbs, Betty Jo Teeter, 1991) By inserting these passages into an alchemical treatise, Newton was making room for nonmechanical laws of vegetation within the natural world: voluntarism justified his alchemical experimentation by reminding him that God could institute any series of causes He willed, not just mechanical ones — making the empirical investigation of active principles both necessary and a form of piety.(Dobbs, Betty Jo Teeter, 1991)

This framework shaped Newton’s understanding of miracles as well. When Leibniz attacked gravity as an occult quality amounting to a “perpetual miracle,” Newton’s response drew on Augustine: “Miracles are so called not because they are the works of God but because they happen seldom & for that reason create wonder.” If they happened constantly according to fixed laws, they would cease to be wonders and become part of the phenomena of nature.(Dobbs, Betty Jo Teeter, 1991) The Augustinian background to this position runs deeper than the polemical retort suggests. Augustine had argued that creation itself was the one true miracle, and that within creation God had implanted “seminal reasons” holding all the possibilities for the future — like the Stoics’ spermatic logoi, these hidden natural causes meant that no event was contra naturam, against nature; all events were simultaneously natural and miraculous in what Dobbs calls a “sacramental view of the whole order of creation.”(Dobbs, Betty Jo Teeter, 1991) By the eleventh century Anselm of Canterbury had already distinguished three categories of events — miraculous, natural, and voluntary — where voluntary events happen by the will of a creature, natural ones by powers God has given to nature, and miraculous ones by the will of God alone.(Dobbs, Betty Jo Teeter, 1991) Newton’s own active principles, which he could not explain mechanically, fit the category of the voluntary or miraculous within this medieval framework.

The Late 1670s: Separation of Alchemy and Gravity

Newton’s vegetative principles, Dobbs argues, represented for him the divinely ordained channel by which God’s will was enacted in nature — not mechanical but operating through some cause comparable to the formal causes of Stoic pneuma, constituting “the channel by which divine ideas were given shape in the natural world.”(Dobbs, Betty Jo Teeter, 1991) When Robert Boyle pressed Newton for his thoughts on “Physicall qualities” in 1678, Newton responded with two speculative aethereal systems that omitted all mention of active principles — because the letter addressed only phenomena Newton classified as mechanical, not because he had abandoned his alchemical convictions.(Dobbs, Betty Jo Teeter, 1991) The multitude of alchemical manuscripts he wrote after 1678 testify to his continued faith in the active vegetative principle.

By the end of the 1670s Newton detached gravity completely from the vital aethereal spirit and made it again fully mechanical — there is therefore no continuity between the quasi-activity he assigned to gravity in the early 1670s and the full activity it achieved after the Principia.(Dobbs, Betty Jo Teeter, 1991) In the period between Boyle’s letter and Halley’s visit to Cambridge in August 1684, Newton recorded at least 15,000 words on his alchemical experimentation alone — behind each brief laboratory report lay untold hours at furnaces of brick, with crucible, mortar and pestle, and apparatus of distillation — and in addition wrote and rewrote many essays on church history, prophecy, and Jewish ceremony.(Dobbs, Betty Jo Teeter, 1991) During this same period he renewed his systematic study of the leading alchemical authorities: Eirenaeus Philalethes, Basilius Valentinus, Hermes Trismegistus, John de Monte Synders, Elias Ashmole’s Theatrum Chemicum Britannicum, and four published books by Michael Maier.(Dobbs, Betty Jo Teeter, 1991)

Newton Abandons the Mechanical Aether

Halley’s challenge to Newton in late 1679, through their celebrated correspondence, provided the stimulus for Newton’s first solution to the problem of celestial dynamics — the mathematical demonstration that planetary orbital motion could be compounded of an inertial component and an inverse-square attraction toward a center of force located at one focus of an elliptical orbit.(Dobbs, Betty Jo Teeter, 1991) This discovery forced a decisive confrontation: Newton’s mathematical demonstration matched Kepler’s empirically verified area law precisely, but the presence of any resisting medium in the heavens would have produced detectable deviations from that prediction, just as terrestrial atmospheres produce deviations in projectile motion.(Dobbs, Betty Jo Teeter, 1991)

Newton’s November 1684 tract De motu corporum in gyrum, sent to the Royal Society, defined “centripetal force” for the first time — “that by which a body is impelled or attracted towards some point regarded as its centre” — and immediately noted that “the resistance is nil,” conclusively demonstrating that celestial motions faced no impediment from any medium.(Dobbs, Betty Jo Teeter, 1991) The essay De aere et aethere, probably written in 1684, attempted to explain cohesion, capillarity, and other short-range phenomena through aerial density gradients rather than aethereal mechanisms, but its tone of uncertainty contrasts sharply with earlier confident aethereal speculations — and, crucially, gravity is nowhere mentioned in it.(Dobbs, Betty Jo Teeter, 1991)(Dobbs, Betty Jo Teeter, 1991) Pendulum experiments reported in the Principia — comparing an empty box with one filled with lead as the pendulum bob — showed no significant increase in aethereal retardation with increased internal matter, providing no evidence for a gravitational aether that interacted with matter’s interior parts.(Dobbs, Betty Jo Teeter, 1991)

In De motu, Newton had equivocated between “impelled” and “attracted” for centripetal force, suggesting no causal mechanism — a stance soon adopted in the Principia itself, marking a decisive shift from seeking a mechanical cause of gravity to mathematical description without specifying cause.(Dobbs, Betty Jo Teeter, 1991) In De Gravitatione — probably written in late 1684 or early 1685, not in Newton’s student days as the Halls argued — he broke with Descartes angrily, dragging out his copy of Descartes’s Principia philosophiae to cite chapter and verse in order “to dispose of his fictions.”(Dobbs, Betty Jo Teeter, 1991)(Dobbs, Betty Jo Teeter, 1991) The manuscript rejected the corporeal nature of the aether “utterly and completely”: “as water offers less resistance to the motion of solid bodies through it than quicksilver does, and air much less than water, and aetherial spaces even less than air-filled ones, should we set aside altogether the force of resistance to the passage of bodies, we must also reject the corporeal nature [of the medium] utterly and completely.”(Dobbs, Betty Jo Teeter, 1991) De Gravitatione was probably intended as an introduction to the Principia as Newton envisioned it in late 1684; as subsequent discoveries produced alterations, the essay became outmoded as a unit while many of its ideas reappeared dispersed throughout the published work, often in scholia.(Dobbs, Betty Jo Teeter, 1991)

The Principia’s third corollary to universal gravitation stated that “All spaces are not equally full,” carrying the argument all the way to the point of an approximately zero quantity of matter in cosmic space.(Dobbs, Betty Jo Teeter, 1991) Having concluded that no mechanical cause could serve, Newton published in the Principia only the “mathematical principles” of gravity, explicitly declining to define “the species or physical qualities of forces, but investigating the quantities and mathematical proportions of them.”(Dobbs, Betty Jo Teeter, 1991) The word “attraction” in the Principia was used quite deliberately in a non-committal sense — “for any endeavor whatever, made by bodies to approach to each other, whether that endeavor arise from the action of the bodies themselves… or whether it arises from the action of the ether or of the air, or of any medium whatever, whether corporeal or incorporeal” — deliberately leaving open the causal question.(Dobbs, Betty Jo Teeter, 1991)

After the Principia’s publication, aethereal explanations for short-range and vegetative phenomena survived without being refuted — the destruction of the gravitational function of the aether by no means destroyed its other uses — and Newton set the problem of short-range phenomena to one side in order to complete his gravitational work.(Dobbs, Betty Jo Teeter, 1991) The Principia’s Proposition VI, requiring all bodies to gravitate in proportion to quantity of matter, ruled out any substance that “lost gravity” upon becoming aether, forcing Newton to reconceive the vegetable spirit as materially homogeneous with ordinary matter yet still active.(Dobbs, Betty Jo Teeter, 1991)(Dobbs, Betty Jo Teeter, 1991)

Newton’s Arian Theology and the Problem of Gravity’s Cause

Two tentative solutions to the problem of gravity’s cause emerged in Newton’s later years. The first was that the omnipresent supreme Deity subsumed gravity directly. The second was that an intermediate agent existed that could account for gravity yet not constitute drag on the motions of heavenly bodies — a solution analogous to the vegetable spirit’s role in vegetation.(Dobbs, Betty Jo Teeter, 1991) Newton’s belief that God was literally omnipresent in space was recorded by David Gregory in 1705: “God must be sensible of every thing, being intimately present with every thing; for he supposes that as God is present in space where there is no body, he is present in space where a body is also present.”(Dobbs, Betty Jo Teeter, 1991) Newton’s conception of God’s omnipresence drew on Jewish theologies of space and on Old Testament passages cited in the General Scholium, bringing together Hebrew authority from Moses and Deuteronomy through John and Acts.(Dobbs, Betty Jo Teeter, 1991)

The unpublished Classical Scholia, designed for Propositions IV-IX of Book III of the 1687 Principia but never published, contained Newton’s argument that the ancients — especially the Pythagoreans and Stoics — had recognized gravitational force and encoded it in mythological forms: “So far I have expounded the properties of gravity. Its cause I by no means recount.”(Dobbs, Betty Jo Teeter, 1991) Newton also noted in connection with these Scholia that his post-Principia methodology was characterized by convergence: he was convinced of findings only when multiple independent lines of investigation aligned.(Dobbs, Betty Jo Teeter, 1991)

He briefly gave credence to a mechanical hypothesis for gravity offered by Nicolas Fatio de Duillier, who supposed an aether with “a very violent agitation” moving in great circles about the earth could provide the driving impulse. By late 1691, however, David Gregory reported that Newton and Halley were laughing at it.(Dobbs, Betty Jo Teeter, 1991) The episode illustrates Newton’s criterion: mechanical solutions were still worth considering, but only until the mathematics ruled them out. In “A Treatise of the System of the World” (probably 1685), Newton had already turned to ancient heliocentric sources, citing Philolaus, Aristarchus, and the Pythagoreans as holders of the older true cosmology, while acknowledging that he could not discover “how the ancients explained” the retention of planets within their orbital paths.(Dobbs, Betty Jo Teeter, 1991)

In drafts for an unrealized Principia edition, Newton explicitly cited the Stoics as having had the right ideas — “a certain infinite spirit pervades all space into infinity, and contains and vivifies the entire world” — quoting the Pauline phrase “In him we live and move and have our being,” which he recognized as drawn from the Stoic poet Aratus.(Dobbs, Betty Jo Teeter, 1991)(Dobbs, Betty Jo Teeter, 1991) In the post-Principia period Newton shifted from a material pneuma to a spiritual pneuma, following the Stoics’ concept of an infinite spirit — this proved to be the essential factor linking divine will with the world of matter in his mature cosmology.(Dobbs, Betty Jo Teeter, 1991) Between 1684 and 1710, Dobbs concludes, Newton’s conceptualization of gravity’s cause was mediated more by ancient Stoic and Platonic thought than by alchemical doctrines, with Newton viewing gravity not as a new discovery but as a restoration of ancient knowledge once possessed by the wise ancients before the decline into idolatry.(Dobbs, Betty Jo Teeter, 1991)

Newton’s Prisca Sapientia and Solar Theology

In the early 1680s Newton composed the treatise Theologiae Gentilis Origines Philosophicae, arguing that ancient civilizations had possessed uncorrupted knowledge of both true religion and true natural philosophy — including Copernican heliocentrism — before falling into idolatry.(Dobbs, Betty Jo Teeter, 1991) Newton interpreted the ancient prytaneum, the perpetual sacred fire, as symbolically representing the heliocentric cosmos with the sun at its center, making the entire world “the true and real temple of God.”(Dobbs, Betty Jo Teeter, 1991) He associated the vegetable spirit of alchemy with the cosmic governance of the Arian Logos so closely that Hermes Trismegistus became in his private writings a pagan type of Christ — the operative alchemical spirit personified.(Dobbs, Betty Jo Teeter, 1991)

Newton correlated the twelve gods of ancient peoples with the seven planets, four elements, and the quintessence, reading alchemy’s basic materials as the first stage of idolatrous corruption of the original true religion, before idolaters forgot the symbolic meaning and began worshipping material bodies as gods in themselves.(Dobbs, Betty Jo Teeter, 1991) In his Theologiae Gentilis papers he argued that “the fire at the heart of the world” held significance at multiple levels simultaneously: historically as the eternal flame in the center of sacred space; religiously as the symbol for the priest of nature restoring true philosophy; cosmologically as heliocentrism validated by Pythagorean tradition; and gravitationally as the sun providing the fermental virtue that activated micromatter throughout the solar system.(Dobbs, Betty Jo Teeter, 1991) Newton described the Philosopher’s Stone material “magnesia” in one of these contexts as “the quintessence of the alchemists that from below links earth with heaven” — a condensed spirit of the world that is “fiery, aery, watery, earthy” and “a corporeal spirit and a spiritual body.”(Dobbs, Betty Jo Teeter, 1991)

Newton studied the Temple of Solomon exhaustively, working from the sources in Ezekiel’s vision rather than from Greek architecture, since he considered Jewish religious structures less corrupted and therefore truer cosmic representations of the heliocentric universe than any other.(Dobbs, Betty Jo Teeter, 1991) He likely hoped to move beyond exact architectural calculations to discover cosmic harmonic proportions, analogous to what he argued the Greeks had encoded in myths of Pan and Orpheus; his conclusions on the Temple appeared posthumously in the Chronology of Ancient Kingdoms Amended.(Dobbs, Betty Jo Teeter, 1991)

In drafts for an unrealized Principia edition in the 1690s, Newton cited Cicero’s De natura deorum as evidence that Stoic natural philosophy had anticipated gravitational centripetal force: Cicero described the universe’s parts as gravitating toward its center through “that rational and intelligent substance which pervades the whole world as the efficient cause of all things.” The word Newton coined for this force, “centripetal,” is used to gloss Cicero’s concept in modern Loeb editions.(Dobbs, Betty Jo Teeter, 1991) Newton also adopted the view, following Stoic scholar Harold Hunt, that Zeno himself had probably explained cosmic coherence through what would later be called centripetal force.(Dobbs, Betty Jo Teeter, 1991)

He drew on Philo of Alexandria’s allegorical reading of Genesis to support his view of an incorporeal divine mind pervading all things — Philo argued Moses called the mind “heaven,” meaning the abode of nature, and that Moses “had already told of the creation of mind and sense-perception” in describing the first day.(Dobbs, Betty Jo Teeter, 1991) Philo and later Renaissance Stoics like Justus Lipsius, who reinterpreted Stoic materialism to create a Platonizing dualism in which God is spiritual and incorporeal yet pervasive throughout space, provided Newton with the conceptual resources to treat gravity as a spiritual force without a corporeal aether.(Dobbs, Betty Jo Teeter, 1991)

In his use of classical authorities Newton was deliberately eclectic: Pythagorean, Stoic, and Christian sources were molded into a single narrative that served his scientific and theological purposes rather than being treated as competing traditions.(Dobbs, Betty Jo Teeter, 1991) He drew on Thales’s doctrine that “all bodies are animate and full of gods” and Pythagoras’s teaching that “harmony is God and the soul of the world” as ancient testimony for a cosmos pervaded by divine activity.(Dobbs, Betty Jo Teeter, 1991) He also used Justin Martyr’s Christianized Pythagorean theology — identifying God as “the blending agent of all ages,” “the mind and animating force of the universe,” and “the light in heaven” — as corroboration from an early Christian authority that the ancient Pythagoreans and the Christian tradition agreed.(Dobbs, Betty Jo Teeter, 1991)

After the Principia, Newton translated several key Hermetic texts from the French, including Nicolas Flamel’s Le Livre de Nicolas Flamel and Hermes Trismegistus’s La Table d’Emeraude and Les Sept Chapitres.(Dobbs, Betty Jo Teeter, 1991) The translations show distinctive peculiarities of phrasing that suggest Newton was rendering the French into a language more comfortable to him — Latin and English were his natural scholarly languages, and French required visible effort.(Dobbs, Betty Jo Teeter, 1991) His appeal to Hermetic texts rested on their supposed antiquity: as a committed believer in prisca sapientia, Newton held that the more ancient the document the less corrupted from original pure knowledge, making Hermes the oldest and therefore “Authores optimi.”(Dobbs, Betty Jo Teeter, 1991) His techniques for deciphering ancient alchemy were so similar to his techniques for interpreting biblical prophecy — both involved decoding “hieroglyphick” language to reach original hidden truth — that Dobbs argues the two pursuits could barely be kept distinct.(Dobbs, Betty Jo Teeter, 1991) The cosmogonic dimension of the La Lumiere sortant des Tenebres, which relates the alchemical process to the first chapter of Genesis — “as the world was formed of a chaos or materia prima which was void and without form… so in our work the stone is made of a chaos or materia prima which by putrefaction is void without form and black” — may have been what drew Newton to translate it.(Dobbs, Betty Jo Teeter, 1991)

The Active Principles in the Opticks

In Query 31 of the 1706 Opticks, Newton openly designated gravity as an “active principle” alongside fermentation and cohesion: particles “are moved by certain active Principles, such as is that of Gravity, and that which causes Fermentation, and the Cohesion of Bodies.” Within the context of Stoic doctrines, Dobbs argues, the divinity of Newton’s active principles was perfectly obvious: defined against the passive principle of matter, they were the eternal Cause, Efficiens, Mind, Reason, Force.(Dobbs, Betty Jo Teeter, 1991) Newton’s concept of God’s “sensorium” (sensorium dei) represented an attempt to explain gravity through analogy with divine perception — just as humans perceive through the brain, God perceives and acts throughout infinite space, which Newton identified as the divine sensorium.(Dobbs, Betty Jo Teeter, 1991)

The Opticks matter theory — Newton’s well-known hierarchical system of parts and pores arranged in three-dimensional netlike patterns — represented his resolution of the tension between atomic permanence and chemical diversity, with the “active principle” of cohesion holding particles in stable arrangements and the “active principle” of fermentation working to change particulate relationships; the pores were filled with these active principles.(Dobbs, Betty Jo Teeter, 1991) Newton’s letter to Bentley in 1693 denied action at a distance in general terms: it was “so great an absurdity” that “inanimate brute matter should (without ye mediation of something else wch is not material) operate upon and affect other matter without mutual contact,” pointing toward a spiritual mediating agent.(Dobbs, Betty Jo Teeter, 1991)

Newton’s Post-Principia Alchemical Work and the Electric Spirit

After publishing the Principia, Newton intensified his alchemical experimentation between 1687 and 1696, producing close to 55,000 words of laboratory notes — starting work in the laboratory on 26 April 1686, the very day Book I of the Principia was received by the Royal Society in London — and an estimated 175,000 words of other alchemical papers.(Dobbs, Betty Jo Teeter, 1991) His post-Principia theological papers continued emphasizing idolatry and reaffirming his Arian heresy, with his voluntarism unshaken.(Dobbs, Betty Jo Teeter, 1991) Newton collaborated closely with Nicolas Fatio de Duillier on shared alchemical interests, including metallic fermentation and specialized alchemical powders; Fatio reported that certain mineral combinations “go through the coulours of the Philosophers” and grow “a heap of trees out of the matter,” concluding “there is plainly a life and a ferment in that composition.”(Dobbs, Betty Jo Teeter, 1991) After the remarkable success of the Principia in restoring true natural philosophy, Newton shifted focus toward more study of natural philosophy as the best way to restore true religion, seeking the border where natural and divine principles fused.(Dobbs, Betty Jo Teeter, 1991)

From 1703 onward, Francis Hauksbee’s experiments at the Royal Society on cold light from phosphors provided Newton with experimental evidence connecting light and electricity. Hauksbee found by late 1706 that he could elicit light within an evacuated glass globe simply by spinning it against his hand; Newton had obtained electrical effects in 1675 by rubbing a glass lens, and he rapidly identified the source of the new luminosity as electrical in nature, prompting him to revise his formulations on light as the primary source of activity in matter.(Dobbs, Betty Jo Teeter, 1991) He identified the electrical substance as a mediating agent between light and gross matter — “an aetherial spirit or spiritual effluvium” — echoing the language of his earlier alchemical work: “Certainly there is some spirit hid in all bodies, by means of which light and bodies act upon each other mutually.”(Dobbs, Betty Jo Teeter, 1991) The early queries of the 1704 Opticks (Queries 1-16) may have deliberately concealed Newton’s private speculations on the vegetable spirit, with public language of “Principles” and “forces” serving as euphemisms for the alchemical active agent he could not state openly in a published work.(Dobbs, Betty Jo Teeter, 1991)

The electric and elastic spirit Newton discussed in the 1713 General Scholium was understood as a universal active medium responsible for cohesion, attraction, repulsion, and the interactions of light and matter — “a certain most subtle spirit which pervades and lies hid in all gross bodies.”(Dobbs, Betty Jo Teeter, 1991) He believed this spirit also played a role in vegetation, generation, nutrition, and the preservation of living bodies from corruption, functioning as an invigorating agent whose “ceasing of vigour upon death may be the reason why the death of animals is accompanied by putrefaction.”(Dobbs, Betty Jo Teeter, 1991) Electricity was not quite equivalent to the vegetable spirit Newton had long sought, but it was certainly related — a natural active substance that facilitated the activity of light with respect to gross matter and that facilitated the internal activities necessary for a living creature to maintain life.(Dobbs, Betty Jo Teeter, 1991) The electric spirit had a further unusual property: it was tangible like a body and active like a spirit, yet so subtle that its emission caused no measurable weight loss even when expanding through a two-foot sphere — a property that made it a candidate for the “spiritual body” Newton had sought in his alchemical work as the material analogue to Christ’s intermediary substance.(Dobbs, Betty Jo Teeter, 1991)

Newton’s electric and elastic spirit from the General Scholium was conceptually distinct from the cosmic aether he introduced in the 1717/18 Opticks queries: the former was microcosmic, pervading the pores of gross bodies and operating at short distances, while the latter was cosmic and responsible for gravity across the heavens.(Dobbs, Betty Jo Teeter, 1991) The creation of the new active cosmic aether in 1717/18 was motivated not by concessions to mechanical philosophers but by Arian theological concerns about God’s direct involvement with matter. Since Newton thought that “the Supreme God does nothing by Himself that He can do by others,” an intermediary agent for gravity would have seemed more appropriate — a created being that acted for the Supreme God to put His will into effect in the moment-to-moment supervision of matter.(Dobbs, Betty Jo Teeter, 1991)

Newton’s Final Arian Creed

Newton’s new aether allowed him to fully reinstate his Arian convictions: in his final creed, God Almighty once more had “His agent, His viceroy, by whom He creates and governs,” a Mediator between Himself and the world and between Himself and human beings.(Dobbs, Betty Jo Teeter, 1991) Newton held in this creed that Jesus was God’s agent in creation and that “God does nothing by himself which he can do by another” — Jesus was “the principle of the creation of God, the Agent, by whom God created this world.”(Dobbs, Betty Jo Teeter, 1991) His anti-Trinitarianism was unambiguous: worshipping Jesus for himself would be idolatry; Jesus was to be worshipped only because his sacrificial death redeemed humanity, and all such worship was ultimately directed “to the glory of God the Father.”(Dobbs, Betty Jo Teeter, 1991)

Sometime late in his life — probably in the 1710s or 1720s — Newton formulated a creed he could recommend for all Christians. Its opening paragraph stated that only God the Father bears the traditional theological attributes of infinity and immortality, that He is all-knowing and eternal, and that He is completely inaccessible to human senses, whereas “other spirits are not so, and are indeed sometimes visible.”(Dobbs, Betty Jo Teeter, 1991) The creed reflects Newton’s final conviction that the Arian cosmology and the Arian theology were a single system: the intermediary Christ-agent who governs creation corresponds, at the theological level, to the cosmic active spirit that mediates between the supreme God and gross matter.

By his last years Newton had also reconciled himself to the concept of a “spiritual body” — probably from the 1710s or 1720s judging by the handwriting of the relevant manuscripts.(Dobbs, Betty Jo Teeter, 1991) This is consistent with his Arian Christology: Christ, as first-created, occupies a unique position intermediate between God and the world, which implies that Christ’s substance is itself intermediary between the incorporeal and the corporeal. The “spiritual body” that had proved so elusive in Newton’s alchemical search — a substance with the activity of spirit and the tangibility of matter — was ultimately a theological concept before it was a physical one.

Newton also believed the comet of 1680 would eventually fall into the sun and incinerate the earth — “and no animals in it could live” — viewing this apocalyptic destruction as the fulfillment of Scripture and as ordained by “the direction of the Supreme Being.”(Dobbs, Betty Jo Teeter, 1991) He saw the restoration of comets to the free spaces of the heavens — rescuing them from Greek cosmology’s sublunary relegation — as a step toward restoring truth in religion through the restoration of true natural philosophy, returning divine powers to the one true God.(Dobbs, Betty Jo Teeter, 1991)

Dobbs traces the evolutionary relationship between Newton’s alchemy and gravity through several distinct phases: initially united in the Dibner MSS 1031 B and the 1675 “Hypothesis”; then separated (the letter to Boyle, 1678); the mechanical gravitational aether then disappeared entirely in 1684; and in the last period of his life, through the connections among light, electricity, and the corpuscles of matter, the two kinds of agents came somewhat closer together again in what Newton called the semicorporeal electricity — a sort of “spiritual body” with some of the functions of the active alchemical agent.(Dobbs, Betty Jo Teeter, 1991)

Newton’s Alchemical Praxis

Newton’s serious alchemical experimentation effectively ended around 1696 when he left Cambridge for London and the Royal Mint. Yet evidence suggests continued engagement: his chemical experiments of December 1692 through June 1693 recorded detailed laboratory observations with antimony, mercury, iron ore, and various precipitates, investigating fermentation and the “fermental virtue” of different materials.(Dobbs, Betty Jo Teeter, 1991) He noted that the “ferment lies only in the ore of iron and not in the red precipitate” of mercury, and that “artificial [mercury] is void of a fermental virtue or at least is not so viscous and active as the natural” — demonstrating the empirical discipline behind his alchemical investigations.(Dobbs, Betty Jo Teeter, 1991) Newton’s Praxis manuscript (Babson MS 420, ca. 1696), a formally organized five-chapter treatise Dobbs describes as his “climactic composition in alchemy,” covered spermatic materials, first matter, the sulfur of the philosophers, the first agent, and practical praxis; although relying heavily on earlier alchemical authors, the conceptualization and organization were certainly Newton’s own.(Dobbs, Betty Jo Teeter, 1991) Newton still had “a parcel of Chymical glasses” at his death, and told Conduitt during his London years that, if he were younger, he would “have another touch at metals.”(Dobbs, Betty Jo Teeter, 1991)

Newton’s Commentary on the Emerald Tablet and the La Lumiere Abstracts

Alongside the Praxis, Newton translated the Emerald Tablet into English and wrote a Latin commentary on it (Keynes MS 28). The commentary frames the alchemical work as a cosmological recreation, likening it to the creation of the world from primordial chaos — “just as the world was created from dark Chaos through the bringing forth of the light and through the separation of the aery firmament and of the waters from the earth, so our work brings forth the beginning out of black Chaos” — and identifies the Mercury of the philosophers as having “body, soul, and spirit” and dominion “in the mineral kingdom, the vegetable kingdom, and the animal kingdom.”(Dobbs, Betty Jo Teeter, 1991) The commentary describes sulfur and quicksilver as differing “only by the degree of digestion and maturity” — sulfur is mature quicksilver and quicksilver immature sulfur — such that they “unite like male and female, and they act on each other, and through that action they are mutually transmuted into each other and procreate a more noble offspring to accomplish the miracles of this one thing.”(Dobbs, Betty Jo Teeter, 1991)

Newton’s abstracts from the late 1680s or early 1690s of the French text La Lumiere sortant des Tenebres (Yahuda MS 30 / Babson MS 414 B) describe the first matter of the philosopher’s work as “a living universal innate spirit, w^{h} in form of an aereal vapour perpetually descends from heaven to earth to fill its porous belly & is afterwards born among impure sulphurs & in growing passes from a volatile nature to a fixt one, giving it self the form of an humidum radicale.”(Dobbs, Betty Jo Teeter, 1991) The abstracts also distinguish the “true” philosophical gold and mercury — “alive and filled with the universal fire,” “a Gold w^{h} is all fire & all life” — from vulgar gold and mercury, which “are dead bodies deprived of spirits” because the active spirit departs whenever metals are exposed to violent furnace flames.(Dobbs, Betty Jo Teeter, 1991) Newton further abstracts the La Lumiere account of metal generation: a “spirit of fire or light” impregnated with the “spirit of the universe” descends, takes on the body of air, becomes enclosed in water, and through sulphureous vapors eventually forms metals, acting on grosser bodies of vegetables and minerals.(Dobbs, Betty Jo Teeter, 1991)

The Praxis in Detail

The Praxis (Babson MS 420) opens with a chapter on “spermatic materials” that identifies the two primary alchemical substances — male and female seeds of metals — with an array of mythological symbols including Flamel’s dragons (winged female and wingless male), the serpents of the caduceus, the king and queen, and the two principal stones that infuse “invisible sulphur” and “spiritual mercury.”(Dobbs, Betty Jo Teeter, 1991) The symbol table Newton prepared for the treatise explicitly presents dual meanings for each planetary sign (gold as both “aurum” and “sol/Apollo”; iron as both “ferrum” and “Mars”), noting that “this ambiguity is sometimes significant” — evidence that Newton engaged alchemy as a multilayered symbolic language, not merely a set of chemical recipes.(Dobbs, Betty Jo Teeter, 1991)

Chapter 2 (“De materia prima”) describes the first matter in language deliberately paradoxical: “a fat viscous heavy juicy mineral, the first matter of all metals, a metallic Gumm… a stone & no water because friable & no stone but water because fluxible in y* fire.”(Dobbs, Betty Jo Teeter, 1991) Chapter 3 (“De Sulphure Philosophorum”) identifies the sulfur of the philosophers as “Chalybs” — “y* true Key of o* work,” a “ffiery Dragon, our infernal secret fire in its kind most highly volatile” — hid in the belly of the Magnet (antimony) and capable of being dissolved in the philosophical mercury to pass into gold by digestion.(Dobbs, Betty Jo Teeter, 1991)

Chapter 4 (“De agente primo”) identifies the first agent as the “rod of Mercury” or Caduceus, which reconciles the two serpents (sulfur and mercury) and is “that salt they call y* salt of y* wise men without which nothing is done… y* Key & beginning of y* work, whereby y* prison is opened in w^{h} ^ lies bound.”(Dobbs, Betty Jo Teeter, 1991) Chapter 5 (“Praxis”) describes the practical procedure: the rod of Mercury and the male and female serpents in the proportion 3:1:2 compose the “three headed Cerberus” which when fermented together grows fluid for fifteen to twenty days, then thickens and turns to a “rotten black pouder” (the nigredo) in forty days.(Dobbs, Betty Jo Teeter, 1991) Multiplication follows: the philosopher’s stone may be multiplied four times, each time gaining tenfold virtue, until “they become oyles shining in y* dark & fit for magicall uses.”(Dobbs, Betty Jo Teeter, 1991) The chapter also describes a “via humida” (wet path) alongside the “via sicca” (dry path), involving the four elemental metals — antimony, copper, iron, and a quintessential element — combined in a “chaos” of equal proportions, from which the philosophical mercury is extracted through repeated sublimation and distillation.(Dobbs, Betty Jo Teeter, 1991) Newton concludes by citing Artephius’s claim that the alchemical fire “dissolves & gives life to stones” and Pontanus’s statement that the fire “is not transmuted w^{h} their matter becaus it is not of their matter, but turns it w^{h} all its feces into y* elixir” — which Newton calls “y* best explication of their saying that y* stone is made of one only thing.”(Dobbs, Betty Jo Teeter, 1991)

Blake’s famous portrait of Newton as “Urizen” — the embodiment of cold mechanistic reason — captures the irony of the eighteenth century’s reception of Newtonian science. Newton himself had written that “when I wrote my treatise about our Systeme I had an eye upon such Principles as might work with considering men for the beleife of a Deity.” The almost total misperception of Newton’s system in the eighteenth century, which purged his alchemy, Arianism, and providential theology to produce a sanitized mechanical empiricism, is one of the greater ironies in the history of science.(Dobbs, Betty Jo Teeter, 1991)

Newton as Model Scientist

For the eighteenth-century vitalists, Newton served a surprising function: not as the patron saint of mechanism, but as the model of a scientist who restricted himself to observable phenomena without speculating about ultimate causes. Canguilhem characterizes the Montpellier vitalists as “prudent positivists” and “Newtonians” — anti-metaphysicians who rejected both mechanism and the metaphysical excesses of animism, asserting only the observational specificity of biological knowledge. “Most of the vitalists referred to Newton as the model of a scientist concerned with observation and experiment” (Wolfe, Charles T., 2010-2015).

This appropriation of Newton cut against the grain of iatromechanism. Where Pitcairne and Boerhaave used Newton to justify reducing the body to particles and tubes, the vitalists used Newton’s own methodological caution — his refusal to feign hypotheses about the cause of gravity — to justify refusing to reduce life to mechanism. Both sides claimed Newton; neither fully represented him.

Newton and the Concept of Milieu

According to Canguilhem, the mechanical notion of milieu, though not the term, appeared with Newton as a concept for a fluid intermediary between physical bodies (Canguilhem, Georges, 1952/2008). In the late eighteenth century, this notion was imported into biology; Lamarck, inspired by Buffon, introduced it but used it only in the plural (Canguilhem, Georges, 1952/2008). Thus, the concept shifted from a physical medium to a biological environment (Canguilhem, Georges, 1952/2008).

The Benchmark for Future Biology

Newton also functioned as a measure of what medicine lacked. William Heberden, writing at the close of the eighteenth century, expressed the hope that Providence would one day send a genius capable of contemplating the animated world with the sagacity shown by Newton in the inanimate, capable of discovering “that great principle of life” upon which all bodily functions depend (Heberden, 1802). Kant’s famous dictum that “no Newton can ever appear who will explain the production of so much as a blade of grass by laws of nature which no purpose has ordered” expressed the opposite conviction — that the organized complexity of living things was categorically beyond Newtonian reduction (Driesch, 1914).

Thurston, the Physiomedical philosopher, used Newton as an analogy: just as Newton’s hypothesis unified mechanics, and Dalton’s unified chemistry, any domain of inquiry becomes a science only when a unifying hypothesis is articulated (Thurston, 1900). For Thurston, Physiomedicalism provided this hypothesis for medicine — a claim that would have surprised Newton.

The Incommensurability of Paradigms

Kuhn’s use of Newton extends beyond illustration to a theoretical point about the nature of scientific change. Einstein’s theory, Kuhn argued, could be accepted only with the recognition that Newton’s was wrong — not merely incomplete but logically incompatible with the replacement (Kuhn, 1962). Newton himself attributed to Galileo a result that Galileo never achieved and that actually violated Galileo’s own explicit laws — the textbook distortion arising because Galileo’s work was now seen through the lens of Newton’s paradigm (Kuhn, 1962). The emergence of Newtonian physics, like the emergence of relativity, was both preceded and accompanied by fundamental philosophical analyses of the contemporary research tradition (Kuhn, 1962). Modern physics has since moved further from Newtonian atomism: following Ernst Mach, Einstein argued that a single particle would have no mass if not for all the rest of matter in the universe, and in Geoffrey Chew’s bootstrap philosophy of subatomic physics every particle’s properties are determined by all other particles, making each one a reflection of the whole. (Bortoft, Henri, 1996)

The Construction of “Newtonianism”

The Principia itself avoided specifying the cause or mechanism of gravitational force, treating “attraction” as a mathematical description of observable regularities rather than an explanation of their cause.(Peter Dear, 2001) This was a deliberate methodological choice, but it created a profound philosophical problem. Continental philosophers, Huygens, Leibniz, Régis, dismissed the Principia as mathematics dressed up as natural philosophy, arguing that gravitational “attraction” without a mechanism was simply occultism with equations.(Peter Dear, 2001) In private correspondence with Richard Bentley in 1692, Newton himself admitted that action at a distance for inanimate matter was inconceivable, suggesting he shared the discomfort his critics expressed publicly.(Peter Dear, 2001)

“Newtonianism” as a public movement was promoted primarily through the Boyle Lectureship, where theologians like Bentley, Samuel Clarke, and William Derham deployed Newton’s natural philosophy to argue for God’s active governance of the cosmos, making Newton a weapon against atheism and materialism.(Peter Dear, 2001) The Leibniz-Clarke correspondence (1715-16) crystallized the opposition: Leibniz accused Newton’s absolute space, gravitational attraction, and divine intervention in nature of being philosophically incoherent; Clarke defended them as Newton’s own.(Peter Dear, 2001)

The “Newtonianism” that prevailed in the later eighteenth century was itself a hybrid of Newton’s, Descartes’s, Leibniz’s, and others’ ideas, purged of Newton’s own intense interests in alchemy, biblical chronology, and heterodox theology, interests that occupied more of Newton’s time than his published natural philosophy.(Peter Dear, 2001) (Peter Dear, 2001) This sanitized Newtonianism, mathematical, mechanistic, theologically safe, was the version that Boerhaave and Pitcairne imported into medicine, and it bore only a partial resemblance to the intellectual commitments of Newton himself.

Newton in the Enlightenment Public Sphere

Porter’s Enlightenment (2000) situates Newton within a broader cultural argument about how the Principia’s publication in 1687, on the eve of the Glorious Revolution, enabled his science to be conscripted for political and religious purposes. Newton himself became Member of Parliament for Cambridge and was rewarded under William and Mary with high office; his science was then enlisted to back the new moral and political order chiefly via the Boyle Lectures, a sermon series endowed to defend Christianity against infidels.(Porter, 2000) Richard Bentley’s 1692 lectures and Samuel Clarke’s 1704–05 series both drew on the Principia to demonstrate divine providential design and to bolster Latitudinarian Anglicanism, establishing that empirical inquiry, intellectual freedom, and rational religion were compatible.

Voltaire and the French philosophes celebrated Newton as one of a triumvirate, with Bacon and Locke, who had demolished Cartesian metaphysics and rebuilt knowledge on the bedrock of experience.(Porter, 2000) In the Lettres philosophiques, Voltaire saluted England as the cradle of liberty and science, using Newton’s achievements as a stick to beat his own patrie. Margaret Jacob has further shown how the Newtonian universe was recruited to bolster the post-1688 constitutional order: Queen Caroline’s garden at Richmond featured busts of Newton, Samuel Clarke, and Locke placed there because “they were the Glory of their Country, and stamp’d a Dignity on Human Nature.”(Porter, 2000) This triangulation of experimental science, rational religion, and Whig constitutional principles became the ideological signature of the British Enlightenment.

Sources

All claims cite evidence cards from:

King, L.S. (1958). The Medical World of the Eighteenth Century. Chicago: University of Chicago Press. [Source ID: king-medicalworld-1958]
Kuhn, T.S. (1962). The Structure of Scientific Revolutions. Chicago: University of Chicago Press. [Source ID: kuhn-scientificrevolutions-1962]
French, R. (2003). Medicine before Science. Cambridge: Cambridge University Press. [Source ID: french-medicinebefore-2003]
Driesch, H. (1914). The History and Theory of Vitalism. London: Macmillan. [Source ID: driesch-historyvitalism-1914]
Wear, A. (2000). Knowledge and Practice in English Medicine, 1550—1680. Cambridge: Cambridge University Press. [Source ID: wear-knowledgepractice-2000]
Principe, L.M. (1998). The Aspiring Adept: Robert Boyle and His Alchemical Quest. Princeton: Princeton University Press. [Source ID: principe-aspiringadept-1998]
Wolfe, C.T. “From Substantival to Functional Vitalism.” [Source ID: wolfe-vitalism-papers]
Canguilhem, G. (2008). Knowledge of Life. New York: Fordham University Press. [Source ID: canguilhem-knowledgeoflife-2008]
King, L.S. (1978). The Philosophy of Medicine. Cambridge: Harvard University Press. [Source ID: king-philosophymedicine-1978]
Heberden, W. (1802). Commentaries on the History and Cure of Diseases. London. [Source ID: heberden-commentaries-1802]
Thurston, J.M. (1900). The Philosophy of Physiomedicalism. Richmond, IN. [Source ID: thurston-physiomedicalism]
Bortoft, H. (1996). The Wholeness of Nature: Goethe’s Way Toward a Science of Conscious Participation in Nature. Edinburgh: Floris Books. [Source ID: bortoft-wholeness-of-nature-1996]

Editorial Notes

Gaps the encyclopaedia compiler flagged for future evidence work, collected from inline markers in the body and frontmatter.

Sources

Influenced by

galileo-galilei rene-descartes robert-boyle

Influenced

herman-boerhaave archibald-pitcairne william-cullen antoine-lavoisier

Isaac Newton

Isaac Newton

Newton and the Mechanical Philosophy

Helmontian Medicine and the Context Newton Displaced

Newtonian Medicine

Newton as Alchemist

The Unity of Truth and the Vegetable Spirit

Newton’s Early Matter Theory and the Problem of Cohesion

From Mechanical Aether to Alchemical Spirit: The 1660s and 1670s

The Vegetation Manuscript (Dibner MSS 1031 B)

The 1675 Hypothesis and Newton’s Arian Turn

Newton’s Voluntarist Theology

The Late 1670s: Separation of Alchemy and Gravity

Newton Abandons the Mechanical Aether

Newton’s Arian Theology and the Problem of Gravity’s Cause

Newton’s Prisca Sapientia and Solar Theology

The Active Principles in the Opticks

Newton’s Post-Principia Alchemical Work and the Electric Spirit

Newton’s Final Arian Creed

Newton’s Alchemical Praxis

Newton’s Commentary on the Emerald Tablet and the La Lumiere Abstracts

The Praxis in Detail

Newton as Model Scientist

Newton and the Concept of Milieu

The Benchmark for Future Biology

The Incommensurability of Paradigms

The Construction of “Newtonianism”

Newton in the Enlightenment Public Sphere

See Also

Sources

Editorial Notes

Influenced by

Influenced

Key Works

Influenced by

Influenced

Sources