Samuel Clarke

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A young chaplain in Norwich, having mastered the Principia while still an undergraduate, set out to prove the existence of God the way a geometer proves a theorem: by a chain of steps each so binding that to grant the first was to be carried, without escape, to the last. That ambition — that the deepest truths of religion could be reached by demonstration, the mind moving from premise to conclusion with the force of arithmetic — is the spine of Samuel Clarke’s life and the source of its central irony. He was an English clergyman and philosopher of the early eighteenth century, the ablest theological defender of the worldview that gathered around Isaac Newton, and for a generation he stood at the center of English argument about how far unaided reason could establish the being and attributes of the divine.

Samuel Clarke (1675–1729), portrait by an unknown artist, circa 1720, National Portrait Gallery (NPG 266) — via Wikimedia Commons (public domain)

Clarke was born at Norwich on 11 October 1675 and schooled there before entering Gonville and Caius College, Cambridge, in 1690, taking his degree in 1695. Newton’s natural philosophy was then new and contested, taught nowhere as doctrine; the standard physics text in the colleges was the Cartesian Traité de physique of Jacques Rohault. Clarke’s first published work, made while barely past his degree, was a Latin translation of that textbook — but its footnotes quietly turned it against itself, supplying at each disputed point the Newtonian correction to Rohault’s vortices and mechanics. For a quarter-century students learned their physics from a Cartesian primer that argued, in its own margins, for the rival system. It was an early and characteristic move: not to attack René Descartes head-on but to annotate him into the new philosophy.

Ordination followed. In 1698 Clarke succeeded William Whiston — the man whose later heterodoxy would so nearly mirror his own — as chaplain to John Moore, Bishop of Norwich, and held a country living at Drayton. In 1706 he came to London, to the rectory of St Benet’s, was introduced at court, and was made a chaplain-in-ordinary to Queen Anne; in 1709 he was instituted rector of St James’s, Westminster, the fashionable parish he kept until his death. The same period brought the second of his services to Newton: a Latin rendering of the Opticks, the Optice of 1706, for which Newton, pleased with its clarity, is said to have paid him five hundred pounds. Clarke moved with unusual ease between the two vocations the age was beginning to separate. He was at once a parish priest reading prayers in Westminster and the man to whom Newton’s circle entrusted the philosophical defense of its mechanics.

Isaac Newton, painted by Godfrey Kneller in 1689; Clarke became the ablest theological defender of Newton’s natural philosophy — via Wikimedia Commons (public domain)

The a priori chain

His reputation rests first on the Boyle Lectures he delivered in two series, in 1704 and 1705, at St Paul’s. The first series was published as A Demonstration of the Being and Attributes of God, framed in answer to Thomas Hobbes, Spinoza, and what Clarke called the deniers of natural and revealed religion; the second, A Discourse Concerning the Unchangeable Obligations of Natural Religion, carried the same method into morals and the evidences of Christian revelation. The two were thereafter printed together so often that they read as one long structure: from the bare fact that anything exists, up through the moral order, to the credibility of the Gospel.

The Demonstration advances by numbered propositions, each presented as forced by the one before. Something has existed from all eternity, for nothing comes from nothing. There has therefore existed from eternity some one unchangeable and independent being. That being must be self-existent — existing not because something else produced it but necessarily, of and from itself. From this necessary existence the rest is meant to follow in order: the being is eternal; it is infinite and everywhere present; it is one only; it is intelligent; it is not a blind necessary cause but a free agent, possessed of will and choice; it is all-powerful, infinitely wise, and a being of perfect goodness, justice, and truth. The whole catalog of the divine attributes — self-existent, independent, eternal, infinite, unchangeable, intelligent, free, all-powerful, wise, just, good — is offered not as the deliverance of faith but as the terminus of a proof.

The argument belongs to the family later named cosmological: reasoning from the existence of contingent things to a self-existent ground. What set Clarke apart was the confidence that the chain could be made strictly demonstrative, that the necessity binding the conclusion was the necessity of mathematics rather than the weaker pull of probability. His own term for it was the argument a priori — though in a sense earlier than the one Immanuel Kant would fix on the phrase. For Clarke the proof was a priori not because it dispensed with experience but because, having granted that something exists, it argued downward from the nature of the cause to the nature of its effects. The hinge of the whole edifice is the third proposition — the claim that the eternal independent being exists necessarily, that its non-existence is not merely false but unthinkable. Critics fastened on that hinge at once. Whether necessity of existence can be wrung from the idea of a being in the way Clarke supposed — whether the very idea of a necessary being names anything the mind can actually conceive — was doubted in his own day and pressed harder by later philosophy. The Demonstration survives less as a case that was won than as the rationalist version of natural theology stated at full stretch: the argument for God built to the tightest tolerance its century could manage.

The correspondence with Leibniz

He is remembered second for the exchange he carried on in 1715 and 1716 with Gottfried Wilhelm Leibniz, ten letters in all — five from each side — conducted not directly but through Caroline of Ansbach, Princess of Wales, who passed the papers between her London chaplain and her former Hanoverian tutor. Leibniz had opened it by remarking to the princess that Newton’s natural philosophy was corroding natural religion: a God who must intervene to keep the cosmic machine in order, he said, is a clumsy artificer forever winding and mending his own watch. Clarke answered for the Newtonian side, almost certainly with Newton’s knowledge, and the dispute widened with each round.

Gottfried Wilhelm Leibniz, portrait by Christoph Bernhard Francke, circa 1700; his exchange of letters with Clarke in 1715–16 ranged over space, time, and the role of God in the cosmos — via Wikimedia Commons (public domain)

It came to rest on the deepest questions the two systems divided over. Is space something real — a kind of vast container, even, in the Newtonian phrasing, an expression of God’s immensity and omnipresence — or is it, as Leibniz held, merely the order of relations among bodies, with no reality of its own apart from the things related? Clarke defended absolute space and time; Leibniz pressed his Principle of Sufficient Reason, that nothing is so without a reason why it is so rather than otherwise, and his Identity of Indiscernibles, to argue that absolute space would leave God without any reason to place the world here rather than there, and so could not be real. Beneath the physics lay a theology. For Leibniz a perfect God had made a perfect machine, complete at its creation and needing no later adjustment; for Clarke a God so withdrawn was no providence at all, and the continual action of God in upholding and ordering the world was not a defect in the design but the very mark of a living dominion. The correspondence ended only with Leibniz’s death in November 1716; Clarke published it, originals and translation together, in 1717. It became one of the most read philosophical books of the century, and remains among the most studied exchanges of the period, valued for compressing the whole quarrel between the Newtonian and Leibnizian worlds into a handful of letters.

The Scripture-Doctrine and the censure

Clarke’s closeness to Newton ran past physics and into doctrine, and there it cost him. In 1712, against the advice of some of Queen Anne’s ministers, he published The Scripture-Doctrine of the Trinity, a work assembling and weighing the biblical texts on the Father, the Son, and the Holy Spirit. Its conclusion, drawn from scripture rather than from the conciliar creeds, was that the Father alone is the supreme, self-existent God, the one underived source of all; the Son and the Spirit are divine but subordinate and derived. The position drew the charge of Arianism — the doctrine, traced to the Alexandrian presbyter Arius, that the Son is not co-eternal and self-existent with the Father — and Clarke was described by his opponents, and by later historians, as Arian or subordinationist in sympathy. A long pamphlet war followed, sharpest against the orthodox divine Daniel Waterland, who undertook the defense of the conciliar Trinity against him.

The matter reached the Convocation of the clergy. In June 1714 its Lower House complained of the book to the Upper House of bishops and sent up extracts to make its case. Clarke answered with a written paper and a spoken defense; the bishops, in the event, passed no formal sentence of heresy against him. But he gave an undertaking to preach and write no further on the subject — a settlement the more outspoken of his anti-Trinitarian allies thought a retreat, and one that did not quiet the correct suspicion that he, like Newton himself, remained privately at odds with the orthodox doctrine. The episode left a permanent mark on his career. A churchman of his gifts might in another age have risen to a bishopric; the cloud of heterodoxy, and his unwillingness to subscribe what he no longer believed, closed the higher preferments of the Church to him. He kept St James’s, and his pen, and little more.

The reason he licensed

What later freethinking and esoteric currents prized in Clarke was never his orthodoxy but his program: the conviction that the central truths of religion stand on disciplined reason, accessible to any sound mind without the aid of revelation. He held it as a defender of the faith — the whole arc of the Boyle Lectures runs from the existence of God through natural morality to the truth of Christian revelation, not away from it. But the method had a logic of its own. Once the being and attributes of God, and the obligations of morality, were established by argument alone, revelation risked becoming a confirmation of what reason already knew rather than a source of what reason could not reach. The deists of the next decades — John Toland and the writers who followed him — took up exactly that opening, pressing reason against the very revelation Clarke meant it to support; and the long current of rational religion runs on past them, to a figure such as Theodore Parker a century and more later. Clarke stands at a hinge his contemporaries felt keenly. The same demonstrative confidence that armed him against Hobbes and Spinoza could be turned, by hands he would have disowned, against the creeds and the church he served.

His instrument was reason, but it was reason of a particular grain. Clarke had read the older Cambridge divines — the circle of Cambridge Platonism, and especially Henry More, whose conception of space as a divine, incorporeal extension lies behind the Newtonian talk of space as the sensorium or immensity of God that Clarke pressed on Leibniz. Yet he was no Platonist of their stamp. Where they had grounded morality and the soul in an intelligible order shining through the mind, Clarke wanted a proof one could write out and check, and his moral philosophy turned on what he called the fitnesses of things — relations of agreement among objects, as fixed and as evident to a clear understanding as the relations of geometry, so that to act unjustly was, for him, a kind of contradiction. That confidence in the plain light of the understanding put him at an angle to his friend John Locke as much as to More: Locke had built knowledge cautiously up from experience and doubted how far reason could reach the foundations of things, while Clarke trusted the chain of demonstration to carry the whole weight of natural religion. The dispute that ran through his century — how much the unaided mind could settle about God, the soul, and duty before any revelation spoke — found in Clarke its most uncompromising affirmative answer.

Texts and scholarship

Clarke’s two Boyle series were gathered and reprinted through the eighteenth century as a single course of natural and revealed religion; the early editions, with their numbered propositions and marginal apparatus, are the primary witness to the a priori argument. The full text of A Discourse Concerning the Being and Attributes of God survives in public-domain transcription, where the chain from the eternity of something to the goodness of the self-existent being can be followed proposition by proposition (Christian Classics Ethereal Library, ccel.org/ccel/clarke_s/being/being.i.html). The correspondence with Leibniz — the ten papers Clarke edited and published in 1717, originals and translation faced — is the other primary monument, and its history, from Caroline’s intermediary role to the absolute-versus-relational quarrel over space, is set out in detail in the scholarly accounts of the exchange (en.wikipedia.org/wiki/Leibniz–Clarke_correspondence). The standard philosophical assessment of Clarke’s metaphysics, his necessitarian proof, his theory of moral fitnesses, and his place between Locke and Berkeley is gathered in the Stanford Encyclopedia of Philosophy (plato.stanford.edu/entries/clarke); the fullest modern monographs are James P. Ferguson’s study of Clarke’s philosophy and theology (1974) and Ezio Vailati’s reconstruction of his metaphysics and the Leibniz debate (Leibniz and Clarke: A Study of Their Correspondence, 1997).

His was not the only Newtonian career to founder on the Trinity. The discipline of weighing scripture as evidence, of submitting doctrine to argument, was in the air around Newton and his allies, and it carried its own hazards for any clergyman who pursued it honestly. Clarke pursued it honestly, and where Richard Bentley had enlisted Newton’s mechanics for the first Boyle Lectures without ever touching his own conformity, Clarke’s reasoning led him to a doctrine the church could not bless. He died on 17 May 1729, his system already being pulled apart by the rationalism he had done much to license.

→ Related: Hermann Samuel Reimarus · Isaac Newton · Gottfried Wilhelm Leibniz · Christianity · Arius · William Whiston · Richard Bentley · Rene Descartes · John Locke · John Toland · Cambridge Platonism · Henry More · Reason · Theodore Parker