“I love that play,” O’Neill declared of The Great God Brown, which remained one of his favorites. Perhaps his fondness derived from the subjective, autobiographical nature of Dion Anthony, one of the characters, who expresses O’Neill’s search for spiritual certainty, as well as his physical qualities and his bitterness. Perhaps O’Neill’s liking sprang from the expressionistic device of the masks, which makes the play one of his strangest and most experimental. Although the critics did not share O’Neill’s feeling, the public was fascinated by the play, which ran for more than 280 performances.

The plot, which is somewhat obscure, involves two young men, friendly rivals from childhood, Dion Anthony and Billy Brown. Dion, an artist, should become a painter, but his father refuses to send him to college. Billy, the stereotypical ideal American boy, goes to college, becomes an architect, and joins his father’s firm. It is Dion who wins the girl, Margaret, despite Billy’s love for her.

Seven years pass. The marriage of Dion and Margaret is unsuccessful: “We communicate in code—when neither has the other’s key!” says Dion, drinking and gambling his inheritance away. Billy, now successful, employs Dion at Margaret’s request, and uses Dion’s creativity to enhance his own designs. Their career rivalry extends to Dion’s friend, the prostitute Cybel, whom Billy keeps as a mistress. The play’s events are understandable, almost banal, until the end of act 2, when Dion suddenly accuses Billy of being unable to love and trying to steal Margaret and Cybel out of envy. Billy admits his love for Margaret; Dion replies, “with a terrible composure”: “No! . . . [Billy] loves me! He loves me because I have always possessed the power he needed for love, because I am love!”

Dion then dies of his alcoholism, but his final wish is for Billy to assume the Dion Anthony identity through the device of the mask. Billy accedes, even playing husband to Margaret. The masquerade cannot be maintained, however, and he is shot as the supposed murderer of Dion.

The interest of the play lies not in the plot outline but in the way O’Neill has developed the characters and themes. The principal device is the use of the mask, a legacy from the Greek theater, which forcefully makes the statement that humans present images to one another, that they rarely expose the truth of themselves. Characters don and remove masks at significant moments: When Dion, in desperation, drops his mask before Margaret to beg for her love, she is so frightened she faints. Billy also drops his mask before Margaret to declare his love for her; she remains masked and rejects him. The expression of the masks changes as the characters alter, age, and experience emotion. The only relationship presented in which the participants are unmasked is that of Dion and Cybel. They are honest together. A masked drama is valuable, according to O’Neill, because it provides “a fresh insight into the inner forces motivating the actions and reactions of men and women.”

The statement of the play, however, is not clear. As representative of American greed and materialism, Billy Brown is an unusually sympathetic character. He is a “good loser” with Margaret, and his success has fallen upon him without aggression on his part. Billy’s assumption of Dion’s identity in the third act, which apparently O’Neill intended to demonstrate the isolation and torment of the artistic psyche, leads to a confusing, almost farcical switching of masks. At one moment Billy, in his own mask, speaks to his employees as “Mr. Brown,” then he runs offstage, returning almost immediately in Dion’s...