All or not at all
As Stephen thinks back, in Proteus, on his insistence that Buck not demean him, he affirms his need to be wholly accepted: "As I am. As I am. All or not at all." The second declaration returns in Circe. Stephen's romantic self-affirmation probably owes its inspiration to Henrik Ibsen, the truth-telling Norwegian playwright whom the young Joyce admired extravagantly. It may also owe something to Oscar Wilde.
Gifford hears "All or not at all" as a reference to Ibsen's first great play, Brand (1866). The eponymous protagonist, whose name means "fire," is a messianic Lutheran priest who believes that God requires a total commitment of the human will. His motto is "Give nothing or give all," or "Be what you are with all your heart, / And not by pieces and in part" (trans. C. H. Herford).
As Gifford notes, this uncompromising message proves difficult not only for Brand but for everyone around him. He leaves his mother alone while she is dying, because she will not give away the money that she wrongly took from her husband. He decides not to move from the unhealthy climate that is killing his young son, because the surrounding farmers need him (he points out that God did not make compromises to save his son). He urges his wife to give away their son's clothes to another woman whose child is freezing, and in doing so, she gives up her hold on life. Brand's relationship with his mother might be supposed to hold particular resonance for Stephen, and to have been suggested to his mind by the conflict with Mulligan, who has accused Stephen of killing his mother.
Thornton hears in "As I am" an echo of Oscar Wilde, of whom Stephen has just been thinking in connection with his emotional involvement with Mulligan. Thornton cites John Z. Bennett's observation that, in chapter 9 of The Picture of Dorian Gray, Dorian says to Basil Hallward, "Don't leave me, Basil, and don't quarrel with me. I am what I am. There is nothing more to be said."