5 July 1687 July 4, 2014 Author: Staff Sir Isaac Newton publishes Philosophiæ Naturalis Principia Mathematica. Famous Words of Inspiration..."Knowledge of what is possible is the beginning of happiness." George Santayana — Click here for more from George Santayana Related posts: 4 July 1569 5 July 1948 5 July 1948 5 July 1946 29 May 1953 29 May 1953 Categories: History Tags: 1687, 5 July