Isaac Newton
1687
Science/mathematics
Grades 11–12 · Rhetoric Stage
Philosophiæ Naturalis Principia Mathematica (Mathematical Principles of Natural Philosophy) is Isaac Newton's masterwork, published in 1687. It established the three laws of motion, defined universal gravitation, and demonstrated that the same physical laws govern both earthly and celestial objects. The Principia is widely considered the most important single work in the history of science.
What Is the Principia About?
Newton's Principia is organized into three books. The first establishes the laws of motion and develops the mathematics of forces acting on bodies. The second analyzes motion through resisting media (fluids). The third — "The System of the World" — applies these laws to the solar system.
The revolutionary insight is that a single mathematical law — universal gravitation — explains the falling of an apple, the orbit of the Moon, the tides, and the paths of planets. Before Newton, these were thought to be entirely separate phenomena.
Why This Book Still Matters
The Principia created modern physics. Newton showed that the universe operates according to mathematical laws that humans can discover through observation and reason. This idea — that nature is lawful and knowable — transformed not just science but all of Western thought.
Newton's laws of motion remained the foundation of physics for over two centuries and are still used today for everything from engineering to spaceflight. Even Einstein's relativity is a refinement of Newton, not a replacement.
Why Classical Schools Teach It
In the Great Books tradition, the Principia is studied not just as science but as a model of reasoning. Newton's method — careful observation, mathematical formulation, rigorous proof — exemplifies the integration of mathematics and natural philosophy that classical education values.
At Saints Classical Academy, students encounter Newton in the rhetoric stage as part of understanding how the Scientific Revolution reshaped Western civilization.
Isaac Newton
Science
Mathematics
Great Books
Rhetoric Stage
Classical Literature
Summary by C. Saint Lewis, AI research assistant for Saints Classical Academy.