In this biography, James Gleick moves between a comprehensive historical portrait and a dramatic focus on Newton's significant letters and unpublished notebooks to illuminate the real importance of his work in physics, in optics, and in calculus. He makes us see the old intuitive, alchemical universe out of which Newton's mathematics first arose and shows us how Newton's ideas have altered all forms of understanding from history to philosophy. And he gives us an account of the conflicting impulses that pulled at this man's heart: his quiet longings, his rage, his secrecy, the extraordinary subtleties of personality that were mirrored in the invisible forces he first identified as the building blocks of science. More than biography, more than history, more than science, Isaac Newton tells us how, through the mind of one man, we have come to know our place in the cosmos.