ISAAC NEWTON SAID he had seen farther by standing on the shoulders of giants, but he did not believe it. He was born into a world of darkness, obscurity, and magic; led a strangely pure and obsessive life, lacking parents, lovers, and friends; quarreled bitterly with great men who crossed his path; veered at least once to the brink of madness; cloaked his work in secrecy; and yet discovered more of the essential core of human knowledge than anyone before or after. He was chief architect of the modern world. He answered the ancient philosophical riddles of light and motion, and he effectively discovered gravity. He showed how to predict the courses of heavenly bodies and so established our place in the cosmos. He made knowledge a thing of substance: quantitative and exact. He established principles, and they are called his laws.

Solitude was the essential part of his genius. As a youth he assimilated or rediscovered most of the mathematics known to humankind and then invented the calculus—the machinery by which the modern world understands change and flow—but kept this treasure to himself. He embraced his isolation through his productive years, devoting himself to the most secret of sciences, alchemy. He feared the light of exposure, shrank from criticism and controversy, and seldom published his work at all. Striving to decipher the riddles of the universe, he emulated the complex secrecy in which he saw them encoded. He stood aloof from other philosophers even after becoming a national icon—Sir Isaac, Master of the Mint, President of the Royal Society, his likeness engraved on medals, his discoveries exalted in verse.

“I don’t know what I may seem to the world,” he said before he died, “but, as to myself, I seem to have been only like a boy playing on the sea-shore, and diverting myself in now and then finding a smoother pebble or a prettier shell than ordinary, whilst the great ocean of truth lay all undiscovered before me.”¹ An evocative simile, much quoted in the centuries that followed, but Newton never played at the seashore, boy or man. Born in a remote country village, the son of an illiterate farmer, he lived in an island nation and explained how the moon and sun tug at the seas to create tides, but he probably never set eyes on the ocean. He understood the sea by abstraction and computation.

His life’s path across the earth’s surface covered barely 150 miles: from a hamlet of rural Lincolnshire southward to the university town of Cambridge and thence to London. He was born in the bedchamber of a stone farmhouse on Christmas 1642 (as the calendar was reckoned in England—but the calendar was drifting out of step with the sun). His father, Isaac Newton, yeoman, had married at thirty-five, fallen ill, and died before his son’s birth. English had a word for that: the child was posthumous, thought unlikely to resemble the father.

This first Isaac Newton left little trace: some sheep, barley, and simple furniture. He endorsed his will with his X, for like most of his countrymen he could neither read nor write. He had worked the land of Woolsthorpe, a place of woods, open heaths, brooks, and springs, where underneath the thin soil lay a gray limestone, from which a few dwellings were built to last longer than the common huts of timber and clay. A road of the Roman Empire passed nearby, running south and north, a reminder of ancient technology still unsurpassed. Sometimes children unearthed antique coins or remains of a villa or wall.²

The second Isaac Newton lived to be eighty-four, gouty and rich. He died in London at the end of the winter of 1727, a prolonged and excruciating death from a kidney stone. England for the first time granted a state funeral to a subject whose attainment lay in the realm of the mind. The Lord Chancellor, two dukes, and three earls bore the pall, with most of the Royal Society following behind. The corpse lay in state in Westminster Abbey for eight days and was buried in its nave. Above the grave was carved an ornate monument in gray and white marble: the figure of Newton, recumbent; the celestial globe, marked with the path of a 1680 comet; and angelic boys playing with a prism and weighing the sun and planets. A Latin inscription hailed his “strength of mind almost divine” and “mathematical principles peculiarly his own” and declared: “Mortals rejoice that there has existed so great an ornament of the human race.” For England, the continent of Europe, and then the rest of the world, Newton’s story was beginning.

The French writer calling himself Voltaire had just reached London. He was amazed by the kingly funeral and exhilarated by all things Newtonian. “A Frenchman arriving in London finds things very different,” he reported. “For us it is the pressure of the moon that causes the tides of the sea; for the English it is the sea that gravitates towards the moon, so that when you think that the moon should give us a high tide, these gentlemen think you should have a low one.” It pleased Voltaire to compare Newton with his nation’s late philosophical hero, René Descartes: “For your Cartesians everything is moved by an impulsion you don’t really understand, for Mr Newton it is by gravitation, the cause of which is hardly better known.” The most fundamental conceptions were new and up for grabs in coffee-houses and salons. “In Paris you see the earth shaped like a melon, in London it is flattened on two sides. For a Cartesian light exists in the air, for a Newtonian it comes from the sun in six and a half minutes.” Descartes was a dreamer; Newton a sage. Descartes experienced poetry and love; Newton did not. “In the course of such a long life he had neither passion nor weakness; he never went near any woman. I have had that confirmed by the doctor and the surgeon who were with him when he died.”³

What Newton learned remains the essence of what we know, as if by our own intuition. Newton’s laws are our laws. We are Newtonians, fervent and devout, when we speak of forces and masses, of action and reaction; when we say that a sports team or political candidate has momentum; when we note the inertia of a tradition or bureaucracy; and when we stretch out an arm and feel the force of gravity all around, pulling earthward. Pre-Newtonians did not feel such a force. Before Newton the English word gravity denoted a mood—seriousness, solemnity—or an intrinsic quality. Objects could have heaviness or lightness, and the heavy ones tended downward, where they belonged.⁴

We have assimilated Newtonianism as knowledge and as faith. We believe our scientists when they compute the past and future tracks of comets and spaceships. What is more, we know they do this not by magic but by mere technique. “The landscape has been so totally changed, the ways of thinking have been so deeply affected, that it is very hard to get hold of what it was like before,” said the cosmologist and relativist Hermann Bondi. “It is very hard to realize how total a change in outlook he produced.”⁵ Creation, Newton saw, unfolds from simple rules, patterns iterated over unlimited distances. So we seek mathematical laws for economic cycles and human behavior. We deem the universe solvable.

He began with foundation stones of knowledge: time, space, motion. I do not define time, space, place, and motion, as being well known to all, he wrote in midlife—then a reclusive professor, recondite theologian and alchemist, seldom leaving his room in Trinity College, Cambridge.⁶ But he did mean to define these terms. He salvaged them from the haze of everyday language. He standardized them. In defining them, he married them, each to the others.

He dipped his quill in an ink of oak galls and wrote a minuscule Latin script, crowding the words edge to edge: The common people conceive those quantities under no other notions but from the relation they bear to sensible objects. And thence arise certain prejudices.… By then he had written more than a million words and published almost none. He wrote for himself, careless of food and sleep. He wrote to calculate, laying down numbers in spidery lines and broad columns. He computed as most people daydream. The flow of his thought slipped back and forth between English and Latin. He wrote to read, copying out books and manuscripts verbatim, sometimes the same text again and again. More determined than joyful, he wrote to reason, to meditate, and to occupy his febrile mind.

His name betokens a system of the world. But for Newton himself there was no completeness, only a questing—dynamic, protean, and unfinished. He never fully detached matter and space from God. He never purged occult, hidden, mystical qualities from his vision of nature. He sought order and believed in order but never averted his eyes from the chaos. He of all people was no Newtonian.

Information flowed faintly and perishably then, through the still small human species, but he created a method and a language that triumphed in his lifetime and gained ascendancy with each passing century. He pushed open a door that led to a new universe: set in absolute time and space, at once measureless and measurable, furnished with science and machines, ruled by industry and natural law. Geometry and motion, motion and geometry: Newton joined them as one. With the coming of Einstein’s relativity, Newtonian science was often said to have been “overthrown” or “replaced,” but that was not so. It had been buttressed and extended.⁷

“Fortunate Newton, happy childhood of science!” said Einstein. “Nature to him was an open book. He stands before us strong, certain, and alone.”⁸

Yet he speaks to us reluctantly and covertly.