This richly detailed 1981 biography captures both the personal life and the scientific career of Isaac Newton, presenting a fully rounded picture of Newton the man, the scientist, the philosopher, the theologian, and the public figure. Professor Westfall treats all aspects of Newton's career, but his account centres on a full description of Newton's achievements in science. Thus the core of the work describes the development of the calculus, the experimentation that altered the direction of the science of optics, and especially the investigations in celestial dynamics that led to the law of universal gravitation.