Here is the story of the scientist who embodied humanity's quest to unveil the hidden forces that constitute the physical world. Gleick moves between a historical portrait & a focus on Newton's letters & unpublished notebooks to illuminate the real importance of his work in physics, in optics, & in calculus. We see the old intuitive, alchemical universe out of which Newton's mathematics first arose & shows us how Newton's ideas have altered all forms of understanding from history to philosophy. And he gives us a moving account of the conflicting impulses that pulled at this man's heart: his quiet longings, his rage, his secrecy, the subtleties of a personality that were mirrored in the invisible forces he first identified as the building blocks of science. Illus.