What does Captain Keller assume about his position in society and his family? Is that challenged in the course of the play? How does he respond?

For Annie Sullivan to succeed with Helen, she must challenge Captain Keller’s assumptions about his role. He is a conservative Southerner who behaves as an authoritarian figure in his home. He also expects respect because he comes from a prominent family. One thing Annie must point out to him is that the family has actually allowed Helen, a child, to run their lives because they have not laid out rules that she must follow. He feels pity toward his daughter, who he assumes to have mental as well as physical disabilities. Sullivan points out that he must think ahead about Helen’s well-being after he passes away (or is buried “under the strawberries,” as she puts it).
She helps initiate a change by insisting on removing Helen from the home for her lessons. His opinion of himself and his family basically do not change, but his behavior in regard to his daughter and his appreciation of Annie’s talents does change after Annie and Helen demonstrate that the Helen understands language.