Isaac Newton 1642–1727
English physicist and mathematician.
Newton's experimental methods and theories in physics, optics, and mathematics crowned the seventeenth century scientific revolution. Building on the work of Galileo Galilei, Johannes Kepler, Nicolaus Copernicus, and others, Newton in his Philosophiae Principia Naturalis Mathematica, or Principia (1687), explained planetary movement by establishing the three laws of motion and a theory of universal gravitation. The image of the universe as a giant clock set into motion by God but governed by mechanical, rational rules is largely Newton's legacy. His exhaustive experiments using prisms to study light and color led to Newton's devising the reflecting telescope, while his contributions to mathematics included determining the binomial theory and developing differential and integral calculus. Beyond scientific investigation, Newton researched and wrote extensively on alchemy and theology.
Newton was born on Christmas day at Woolsthorpe, Lincolnshire. His father, an illiterate farmer, had died three months before his son's birth. Hannah Ayscough Newton, Newton's mother, remarried when her son was three, and left with her new husband, a wealthy minister, to rear a second family in neighboring North Witham. Raised by his grandmother, Newton remained separated from his mother until he was eleven, when Hannah, widowed a second time, returned to Woolsthorpe hoping her son would learn to manage her property. Displaying neither the temperament nor ambition for yeomanry, Newton soon returned to grammar school to prepare for university. He graduated from Trinity College, Cambridge, in 1665 with a bachelor degree, but without any record of note. An outbreak of the plague closed the university for the next two years, and Newton returned to Woolsthorpe. In a burst of allout study and experimentation, Newton realized some of his most ingenious work in astronomy, calculus, optics, and mechanics. When Newton returned to Cambridge in 1667 to complete a master of arts degree, Isaac Barrow, Lucasian chair in mathematics, read some of Newton's privately circulated papers, and immediately championed Newton's intellectual capability. Barrow retired in 1669, and, at his urging, Newton was appointed mathematics professor. By age 27, Newton
had established a reputation for brilliance. Biographers have speculated, however, that the early years of maternal abandon had deeply scarred his psyche. Throughout his life Newton over-reacted to criticism—lashing out irrationally, and often vindictively, not only at rivals, but often becoming suspicious of his friends, such as John Locke and Samuel Pepys. He was reluctant to share his work with fellow scientists or to give credit to them for their influence upon his work. Unable to withstand the critical scrutiny of his peers, Newton established a pattern of refusing to publish his work until years after its completion. He suffered nervous breakdowns in 1678 and in 1693. In 1696 Newton left Cambridge for London when appointed first warden, and three years later was appointed master of the mint—a post that carried cache and paid handsomely. Thought to be incorruptible, Newton proved to be an effective administrator who relentlessly ferreted out counterfeiters during a period of recoinage. In his later years Newton devoted most of his writing to alchemy and theology, subjects that had held his interest all his life. Newton rejected trinitarianism, an orthodox religious doctrine in the seventeenth century, but, mindful of Galileo's fate a generation earlier, did not make his beliefs publicly known. Although by then he had ended most of his scientific experimentation, Newton was regarded as the dean of English science, and elected President of the Royal Society in 1703. His tenure was marred by an enduring feud with astronomer John Flamsteed, which also earned Newton a reputation for autocratic rule. Newton was knighted in 1705 and died in 1727, leaving a considerable estate.
Newton published his first paper, "Of Colours," in 1672. Based on a series of lectures he gave in his first three years of teaching, the treatise explained his theories on light and color, and eventually became Book One of Opticks. In his experiments with prisms, Newton had broken down white light into a spectrum of primary colors, which led to his theory that light was composed of individual particles or corpuscles. Book Two described experiments Newton conducted with colors of thin films leading to his theory that light could be both reflected and refracted. Book Two was issued along with "Hypothesis Explaining the Properties of Light" (1675), a controversial essay that outlined a new system of nature. The final section of the Opticks contains a series of "Queries" posed as hypotheses. Newton refused to publish a completed edition of the Opticks until 1704, a year after the death of his nemesis Hooke. Originally published in English, Opticks was the most widely read of Newton's books. Later English editions were issued in 1717 and 1721. Latin editions appeared in 1706 and 1719. The theories contained in the Principia (1687) had been worked out twenty years prior during the two years Newton lived in Woolsthorpe because of the plague. When astronomer Edmond Halley in 1684 asked Newton if he could describe the orbit of planets, Newton replied that the path was elliptical, and that he had mathematically worked out his theory, but had long since misplaced the computations. After Halley's prodding Newton redid his calculations and sent them to him along with a tract, De Motu ("On Motion"). With Halley's encouragement and financial patronage, Newton elaborated and expanded his work, resulting in the Principia. Originally published in Latin, an English edition wasn't issued until 1729. Newton added a "General Scholium" to later editions in which he defended his methodologies. Subsequent editions of the Principia were issued in 1713 and 1726. Composed of nearly two million words, Newton's theology and alchemy notebooks far surpassed in quantity Newton's scientific papers. Many of the notebooks, however, contain passages Newton recorded from the works of others he was studying. Newton's principal theological writings—The Chronology of Ancient Kingdoms Amended (1728) and Observations upon the Prophecies of Daniel and the Apocalypse of St. John (1733)—were published after his death. He believed that astronomical computations could be used to match events in the Bible to a chronology of human history, and estimated the universe to be 5000 years old. Newton did not eliminate God from the universe; rather, God remained as prime mover, poised to intervene to keep the planets in their orbits and the sun, stars, and moon from colliding. Newton's notebooks on alchemy suggest that his experiments were an integral part of his understanding of natural phenomena, rather than mystical or occult excursions.
Although Newton's first published paper on light was generally well-received, a few scientists responded with skepticism, questioning his departure from the standard scientific method of establishing a hypothesis or exploring alternative theories. Newton's ideas were especially challenged by Hooke and others who subscribed to the Cartesian theory that light was the result of wave-like motions through a material medium. The essay "Hypothesis Concerning the Properties of Light" prompted outrage from Hooke who was convinced that Newton had appropriated his ideas. Although Newton gained international fame after publication of the Principia, his paranoid personality dampened the accolades his peers might otherwise have bestowed. Time lapses between work completion and subsequent publication led to disputes with others over who discovered what and when. He engaged in a long-standing feud with Gottfried Wilhelm Leibniz, who felt certain Newton had stolen his ideas on calculus. Many contemporaries believed Newton abused his power as President of the Royal Society, domineering the careers of young scientists while sabotaging rivals. Until this century, Newtonian criticism had been primarily limited to the scientific work, leading to a skewed assessment of his world view. Nineteenth-century Romantics, including William Blake and William Wordsworth, denounced Newton for what they perceived as his ushering in a spiritless, mechanical universe. Newtonian science did create a new paradigm of thought that affected virtually all areas of western culture, and was germane to the Age of Enlightenment and subsequent "revolutions" in history, law, and political-economy. While some of Newton's scientific principles have been supplanted by the theory of relativity and other advances in twentieth-century science, many remain valid. Today much Newtonian scholarship focuses on the increasingly available theological and alchemical manuscripts. Many critics view both Newton's scientific and non-scientific work as essential components for understanding Newton and as the basis for knowing how he comprehended the world.