An inspiring drama of courage, persistence, and faith, The Miracle Worker by William Gibson presents an interesting interplay of characters. Here is a discussion of the salient characteristics of the main characters:
Captain Arthur Keller
The patriarch of the Keller family, Captain Keller is accustomed to having the final word on all household decisions. He has "stopped believing in wonders" regarding his child, Helen. Although he indulges Helen, after a while he decides that it may be better to put her into an institution. However, he does love his wife and agrees to write to The Perkins Institute in order to learn if anything can be done for Helen. When Anne Sullivan arrives, Captain Keller regards her assertiveness as offensive and unbecoming of a woman; thus, he is in constant conflict with her as he is skeptical of her abilities.
Mrs. Keller [Kate Keller]
The main characteristic of Mrs. Keller is her overwhelming guilt over what has happened to her daughter. As a result of this guilt, she spoils her child, who acts like a feral animal. As opposed to her husband, Kate refuses to give up hope that something can be done; thus, she begs her husband to not fire Anne when he becomes angry with her and to allow Anne to isolate Helen from them in the garden house for a week. It is Kate Keller's enduring love for her daughter and hope that she will be able to learn that supercedes all else.
The son of Captain Keller, James is rather unmotivated, often sarcastic, and especially jealous of all the attention given to Helen. However, he becomes the champion of Anne Sullivan, supporting her efforts to teach Helen. In Act III, for example, he argues with his father to allow Anne to make Helen fill the pitcher that she has flung at Anne. With this show of inner strength, James wins some respect from his father.
A child of the slums who herself has been blind, Anne has learned to endure. She has the inner strength to insist that Helen learn and behave properly. In addition to her fortitude, Anne believes in the power of the soul, persisting in tapping this soul of Helen. Driven by this belief and her guilt over the death of her brother, Anne finally breaks through to Helen and becomes "the miracle worker." Her victory is both one for Helen and for herself as she has conquered her inner demons and the forces of Captain Keller's disapproval of her as well as having helped Helen.
Helen, of course, is the main character of this play. Her handicaps notwithstanding, Helen is obviously a girl of high intellect and cleverness as evinced in her locking Anne in her room and her other devious acts. Indeed, her brillance is the key to her breakthrough to the world of learning since she was only six months when she learned to say "wa-wa," the key to her awakening. Her strong will, then, is turned to her great success as Anne Sullivan helps her make the definitive transtition.