From "Conspiracy in Philadelphia":
This hostility to religious oaths as a requirement of holding political office was basic to the Dissenters and Protestant nonconformists generally, who faced an oath of allegiance to the Church of England and not just to the Trinity.63 This same hostility later flared up at the Constitutional Convention, as we shall see. The intellectual basis of a crucial alliance in 1787 between dissenting Protestantism and incipient unitarianism was the shared faith in natural law. Where did this faith come from?
It should be clear that it did not come from Thomas Aquinas or medieval scholasticism generally. The Framers did not read the scholastics, nor did many other Protestant thinkers of the eighteenth century. They were far more likely to read René Descartes, or summaries of his thought.
The Lure of Geometry
Descartes’ vision of a logical, geometrical universe fascinated political thinkers throughout the seventeenth century. Thomas Hobbes’ defense of the state’s near-absolute sovereignty in Leviathan (1651) was surely governed by his Cartesian worldview: a political world analyzed in terms of mathematical precision. Belief in mathematical laws that govern the affairs of men – laws that can be discovered by the enlightened few – remained a tenet of Continental Enlightenment thought, especially in France.64
Nevertheless, more was needed than Descartes’ mere theoretical assertions in order to make this mathematical vision a part of all educated Englishmen’s thinking. French speculation was not sufficient to persuade these “practical men of affairs.” What was needed was a practical and seemingly irrefutable demonstration of the inescapable relationship between man’s rigorous mathematical speculations and the physical operations of the external world. This was what Sir Isaac Newton’s Principia gave to mankind in 1687. His work was part of a one-generation shift in worldview that transformed European thinking. This era was the beginning of both rationalism and romanticism, the eighteenth century’s incarnation of two sides of autonomous man’s thinking: rationalism and irrationalism.65
In philosophy, the reaction was pantheism, especially in the works of Spinoza. In trinitarian religion, a dual reaction was evident within a decade of Newton’s death: the rise of Arminian Methodism in England and the revivalism of the Great Awakening in the colonies. In the colonial case, the authority of the established churches over the thinking of the laity, especially in politics, received a mortal wound from which it has yet to recover, especially in Puritan New England.66
Isaac Newton: The Trojan Horse
The central figure in Enlightenment thought was Isaac Newton. This is a conventional view of the Enlightenment. There is little question that Newton was a touchstone for philosophy in the United States in the eighteenth century. When men spoke of Nature with a capital N, they meant nature as interpreted by Newton: a world whose operations are governed by religiously neutral mathematics, either as a primary cause (autonomously) or secondary, under God. I call this the unitarian worldview, a world in which the doctrine of the trinity is superfluous scientifically.
Isaac Newton was a secret unitarian. Had he admitted this fact in public, he would have lost his job at Cambridge University, as his friend and associate William Whiston did, just as Newton had warned him, advising that he continue to deceive the public. Newton was the dominant intellectual influence in the eighteenth century, and he remained so until the publication of Darwin’s Origin of Species (1859). His mechanical model of a not-quite autonomous cosmos was then stripped of its few traces of deity by his successors. His ideal, so stripped, was unitarian: a world that can be understood by its effects in terms of reason rather than traditional theological confession. It is in this sense that I discuss the world of the Framers as Newtonian. With Isaac Newton, we can mark the overwhelming triumph of Enlightenment faith in the English-speaking world. From 1690 to 1790, we can date a major and nearly self-contained intellectual era that laid the philosophical and cultural foundations of modern atheism.67 Because of what was done during that century – begun by Newton and ended by the French Revolution – and also because of what Darwin did in 1859, we live in a culture in which, for the first time in mankind’s history, belief in God is optional, a world in which “The option of not believing has eradicated God as a shared basis of thought and experience and retired him to a private or at best subcultural role. The bulk of modern thought has simply dispensed with God.”68 It began with Newton, of whom Alexander Pope wrote:
Nature and Nature’s Laws lay hid in Night.
God said, Let Newton be! and All was Light.
American Christians consented, step by step, to the transformation of this nation into a theologically pluralistic republic. It began with natural law theory. The Puritans had been compromised to some degree by natural law doctrine from the beginning, and this influence increased after the magisterial successes of Isaac Newton in the field of natural philosophy. They did not know that he had abandoned trinitarian Christianity and had become an Arian, although a very private and cautious one, at least a decade before his Principia (1687) was published.69 They also were unaware of another side of Newton, a side which was suppressed by his followers immediately after his death, and which was then forgotten for two and a half centuries (and is known only to highly specialized historians today): his occultism.
Newton was a dedicated practitioner of the occult art of alchemy.[...] (pp. 37-40.)
I reproduce this chiefly because I have found North is right to stress Newton's influence. One problem with the American Founding is that many many notable historical thinkers influenced them and it's tough to sort it all out. Jefferson claimed Locke, Sidney, Aristotle and Cicero as the four chief influences for the Declaration and certainly he was right insofar as those four monumentally influenced the American Founding. Gregg Frazer's work stresses Joseph Priestley, another monumental influence on the American Founding. Richard Price and James Burgh also deserve honorable mention. Likewise Isaac Newton and his mathematical approach to metaphysical truth greatly influenced the American Founding. North's book also details the Freemasonic influence on the American Founding. America's Founders viewed themselves as almost literal architects in "building" governments from mathematical/geometric principles. No wonder their affinity for the Freemasons.