astronomer, natural philosopher, alchemist and theologian who has been considered by many to be the greatest and most influential scientist who ever lived. His monograph PhilosophiƦ Naturalis Principia Mathematica, published in 1687, laid the foundations for most of classical mechanics. In this work, Newton described universal gravitation and the three laws of motion, which dominated the scientific view of the physical universe for the next three centuries. Newton showed that the motion of objects on Earth and that of celestial bodies is governed by the same set of natural laws: by demonstrating the consistency between Kepler's laws of planetary motion and his theory of gravitation he removed the last doubts about heliocentrism and advanced the scientific revolution. The Principia is generally considered to be one of the most important scientific books ever written, both due to the specific physical laws the work successfully described, and for its style, which assisted in setting standards for scientific publication down to the present time. We are delighted to publish this classic book as part of our extensive Classic Library collection. Many of the books in our collection have been out of print for decades, and therefore have not been accessible to the general public. The aim of our publishing program is to facilitate rapid access to this vast reservoir of literature, and our view is that this is a significant literary work, which deserves to be brought back into print after many decades. The contents of the vast majority of titles in the Classic Library have been scanned from the original works. To ensure a high quality product, each title has been meticulously hand curated by our staff. Our philosophy has been guided by a desire to provide the reader with a book that is as close as possible to ownership of the original work. We hope that you will enjoy this wonderful classic work, and that for you it becomes an enriching experience.