According to Newton, the natural motion of an object is uniform motion in a straight line. This is the motion an object will exhibit if no forces act upon it.

Here's a breakdown:

* Uniform motion: This means the object moves at a constant speed.

* Straight line: This means the object does not change direction.

This concept is encapsulated in Newton's First Law of Motion (also known as the Law of Inertia), which states:

> An object at rest will stay at rest, and an object in motion will stay in motion at a constant velocity unless acted upon by a net external force.

So, if you push a book across a table, it will eventually stop due to friction. However, if there was no friction, it would keep moving forever at the same speed and direction.