Standing in an unstable universe where distances contract and clocks slow down, and time and space are plastic, Albert Einstein cast a wistful backward glance at Isaac Newton. "Fortunate Newton, happy childhood of science!" he wrote. "Nature to him was an open book, whose letters he could read without effort."
A child's first tasks are to walk and talk and understand his little universe. Newton, the 17th century's formidable prodigy, simply enlarged the project. The first of his family of Lincolnshire yeomen to be able to write his name, Newton grew into a touchy, passionately focused introvert who could go without sleep for days and live on bread and wine, and, at an astonishingly precocious age, absorbed everything important that was known to science up to that time (the works of Aristotle and, after that, the new men who superseded him: Copernicus, Kepler, Descartes and Galileo, who died in 1642, the year Newton was born). Riding on the shoulders of giants--and correcting the giants where they went wrong--Newton began assembling and perfecting the Newtonian universe, a miraculously predictable and rational clockwork creation held together by his universal gravitation and regulated by his elegant laws of motion.
Amazingly, the bulk of Newton's formative thought was accomplished at 23 and 24, while he was rusticated to Lincolnshire by the Great Plague, which shut down Cambridge University several months at a time from 1665 to 1667. Newton lived to be 84. Before he was done, his comprehensive intelligence--with which he seemed to have thought and tinkered his way into the very mind of God--had set off not one but four scientific revolutions--in mathematics (he invented the calculus, as did Leibniz in Germany, independent of Newton), in optics (he invented the reflecting telescope, and his experiments with spectrums established the nature of color and the heterogeneous components of sunlight), in mechanics (his three laws of motion changed the world) and with his understanding of gravity. The last explained the phenomena of heaven and earth in a single mathematical system--or did until Einstein arrived.
Newton is the man of the century for this reason: by imagining--and proving--a rational universe, he in effect redesigned the human mind. Newton gave it not only intellectual tools undreamed of before, but with them, unprecedented self-confidence and ambition. If Shakespeare incomparably enlarged humanity's conception of itself, Newton--working later, in the turmoil of the English civil war and Restoration--set in place those cooler universals that were the premise of the 18th century's Age of Reason and the dynamic of the 19th century's age of revolutions--industrial, political and social.
In a sense, all the change that shaped the world until the onset of modernity had its origins in Newton's mind. For what he showed was this: the universe is knowable and governed by universal laws--therefore predictable, therefore perfectible by human reason and will. Go beyond science to politics and society: if all bodies, great and small, are subject to the same universal laws, the idea leads on to democracy (equality of all humans great and small) and the principle of universal justice. Newton's laws ousted older preferments of feudal hierarchy and magic (though Newton himself devoted frustrated years to the study of alchemy) and installed the authority of the inquiring human mind.