Simplify the following text for a Grade 10 native English-speaking person.
Original: John Stuart Mill , in his work , On Liberty , was the first to recognize the difference between liberty as the freedom to act and liberty as the absence of coercion ( being forced to do something ) .
Simplified: John Stuart Mill , in his work , On Liberty , was the first to recognize the difference between liberty as the freedom to act and liberty as the absence of coercion .