I think that Harper Lee presents courage in Chapter 11 by introducing Mrs Dubose and making Atticus tell Jem to read to her despite his fear of her.

“I wanted you to see what real courage is, instead of getting the idea that courage is a man with a gun in his hand.”

The quotation above was said by Atticus to Jem. I think that Atticus was trying to tell Jem that Mrs Dubose had more courage than a ‘man with a gun’ as she was fighting for her life whilst trying to break off morphine. A man with a gun appears to be powerful and strong but in reality, they’re just like anyone else with the ability to kill.