People
Courage is resistance to fear, mastery of fear -- not absence of fear.
— Mark Twain

Behind the line May contain spoilers.
Our reading
An editorial interpretation.
The passage defines courage through a person's response to fear rather than through fear's absence. Resistance and mastery make bravery sound active, something exercised in the presence of difficulty. The distinction allows fear and courage to exist together within the same experience.
Context reviewed