The Nature of Fear and Courage
Harry Potter and the Prisoner of AzkabanHow characters confront their fears, from the Boggart lesson to Harry's fight against the Dementors.
increasing
Bearing strength in each event
decreasing
The Boggart lesson

Facing Fear
The Boggart
Lupin teaches the class to face their fears using the Riddikulus charm. Each student confronts a personalized fear. Neville faces Snape, Ron faces spiders, etc.
The Method
Laughter is the weapon against fear. By making the fear ridiculous, they take away its power. The lesson is both practical and psychological.
Harry's Unfinished Business
Lupin stops Harry from facing the Boggart, because he fears it would become a Dementor. Harry's fear is deeper and more complex. The lesson sets up his later struggle.
Harry's fear of the Dementors

The Deepest Fear
The Physical Reaction
Harry faints at the sight of Dementors. He hears his mother's screams. The fear is paralyzing. He feels shame and weakness.
The Determination
Despite the fear, Harry asks Lupin to teach him. He practices the Patronus Charm repeatedly. He does not give up.
The Triumph
Harry eventually produces a full Patronus. He conquers the fear that has haunted him. The theme is that courage is not the absence of fear, but the will to act despite it.
First Defense Against the Dark Arts lesson
Throughout the year