Aristotle’s Fallacy

Aristotle based his idea on common everyday observations:

• A rolling ball on a surface stops after traveling some distance
• A paper plane eventually falls after being thrown
• A paper boat slows down and stops after initial propulsion

From these examples, it seemed clear that force must be continuously applied to keep things moving.

The Problem with Aristotle's Thinking

Aristotle did not identify the hidden opposing forces that were actually causing the objects to stop. These forces are:

• Friction – acts on rolling balls
• Viscous drag/Viscous force – acts on paper planes moving through air
• Viscous force of water – acts on paper boats moving in water

Galileo discovered that objects stop moving because of resistive or opposing forces, not because the force is no longer applied. He showed that:

• All objects naturally continue moving once set in motion
• The only reason they stop is due to friction, air resistance, or water resistance
• These opposing forces slow down and eventually stop the motion

The Corrected Statement

Correct Version: "To maintain uniform motion of a body, an additional external force is required only to overcome the opposing forces like friction and viscous drag, not to maintain the motion itself."