Newton didn't say the natural world follows "rules" in the sense of being arbitrary regulations. Instead, he described fundamental laws governing the universe based on his observations and mathematical reasoning. These laws, known as Newton's Laws of Motion and Newton's Law of Universal Gravitation, are often summarized as:

Newton's Laws of Motion:

1. Inertia: An object at rest stays at rest and an object in motion stays in motion with the same speed and in the same direction unless acted upon by an unbalanced force.

2. Acceleration: The acceleration of an object is directly proportional to the net force acting on it and inversely proportional to its mass.

3. Action-Reaction: For every action, there is an equal and opposite reaction.

Newton's Law of Universal Gravitation:

* Every particle in the universe attracts every other particle with a force that is proportional to the product of their masses and inversely proportional to the square of the distance between their centers.

These laws, along with his development of calculus, revolutionized our understanding of physics and laid the foundation for modern science.

It's important to note:

* These laws are not "rules" in the sense of being absolute and unchanging. Einstein's theory of relativity, for example, demonstrated that these laws are approximations that hold true under certain conditions.

* Newton's laws do not explain *why* the universe behaves in this way, only *how* it behaves. The "why" is still a subject of ongoing scientific inquiry.

Despite these limitations, Newton's laws remain remarkably accurate in describing the motion of everyday objects and provide a powerful framework for understanding the universe.