Sir Isaac Newton made significant advancements in scientific understanding during the Enlightenment, particularly with his laws of motion and universal gravitation. His seminal work, "Philosophiæ Naturalis Principia Mathematica," published in 1687, laid the groundwork for classical mechanics, fundamentally changing the way the natural world was understood. This work combined mathematics with empirical observation, establishing the scientific method. Newton's discoveries also challenged existing beliefs about the universe, bridging the gap between science and philosophy and influencing later Enlightenment thinkers. His contributions paved the way for the modern scientific approach, making him one of the most influential figures in the history of science.