Isaac Newton Isaac Newton (1642–1727) was one of the foremost scientific thinkers of the Enlightenment. An incredibly weak newborn, Newton was not expected to live long after birth, a detail that makes his eighty-four-year lifespan yet another of his remarkable accomplishments. Newton was sent to live with his grandmother after the death of his father and the remarriage of his mother. This forced separation from his mother proved very traumatic for Newton and had a profound impact on his personality, feeding into a chronic insecurity that would later make him highly sensitive to criticism and reluctant to publish some of his greatest works. After the passing of his stepfather, Newton’s mother charged the young man with managing her estate. Young Newton had little interest in farm life; his lack of interest in tending to livestock soon became obvious, at which point he returned to school. During his relatively short time on his mother’s estate, Newton’s clever mind was still hard at work, and the young man designed several useful machines including a windmill. Isaac Newton, like other scholars of the age, immersed himself in the writings of Aristotle while studying at Cambridge University. The Enlightenment was gaining momentum at this time, and the works of René Descartes soon captured Newton’s attention. Descartes’s work proved highly influential, and ultimately helped shift Newton’s view of the natural world. Newton challenged previously accepted notions and conceptions, instead relying on his own powers of observation and experimentation to better understand the world around him. In 1665, the plague that swept through Europe closed Cambridge, forcing Newton to assume a two-year course of independent study, during which he laid the foundation for calculus and studied circular motion. While Newton is perhaps best known for his “discovery” and subsequent explanation of the forces of gravity and gravitation, he also described numerous mathematical principles that govern the natural world in his book Principia, published in 1687..