Themes are the fundamental and often universal ideas explored in a literary work.
Arthur, Sybil, Sheila, Eric, and Gerald must come to terms with their guilt, leading to Eva/Daisy’s demise. The Inspector wants the family to accept the pain it has caused Eva/Daisy. In this way, guilt plays an important role in the Inspector’s politics. Although he does not describe his politics explicitly, he appears to be a socialist, and for him, socialism demands that human beings look out for one another, do their absolute best to avoid harming each other. When people do wrong, they must then explain, to themselves and others, the wrongness of their actions.
Sheila is the most willing to see that she has erred, in having Eva/Daisy removed from her job at Milward’s. Gerald, too, understands that his relationship with Eva/Daisy has caused her pain, and that that pain might have brought her to suicide. Arthur and Sybil, however, are far less willing to accept their guilt. Arthur is more concerned with the family’s good name, and Sybil believes that in denying Eva/Daisy charity, she did what any person in her position should have done. Eric feels some version of Sheila’s guilt, but his drunkenness shades his emotions somewhat. He is disturbed to know, however, that there are parts of his relationship with the girl he does not even remember, on account of steady inebriation.
The play’s final, perplexing scene, in which Arthur learns that a girl really has committed suicide, again raises the question of culpability among the characters. By the end of Act Three, Gerald and Arthur, for their own reasons, have convinced themselves and the other Birlings that the Inspector has fooled them completely. They think that, though they have done wrong individually, these wrongs have not added up to cause one person’s death. But if, the playwright implies, the dead person at the close of the play is the same person with whom each character has interacted, then their guilt is no longer individual, but instead collective, although only Sheila seems to understand this fully. Priestley leaves this question open as the play ends.
The act of killing oneself, or of losing oneself entirely, is central to the play’s events. The play’s predicament is the supposed death of a girl named Eva Smith, or Daisy Renton. Eva/Daisy has killed herself, the Inspector argues, because all society has abandoned her. Her only remaining choice was to end her life. The Inspector sees suicide as the response to a culture of selfishness, which he believes to permeate capitalist society. No one was willing to lend Eva/Daisy a hand, and the Birlings discarded her when she was no longer compliant or useful to them. She had no friends or family to fall back on.
There is a larger “suicidal” idea in the play, not in the literal sense of one person’s death, but on the social plane. The Inspector implies that if men and women continue to behave callously to one another in the industrialized countries of the West, then those countries, as entities, will “commit suicide.” That is, the Inspector’s warning to the Birlings foreshadows the cataclysms of the World Wars One and Two, which the audience in 1946 would understand to follow quickly upon the events of the play.
Throughout his questioning, the Inspector takes on the role of a professor or guide. He interrogates the Birlings and Gerald, and he wants them to admit culpability for Eva/Daisy’s death. Further, he wants them to learn what they have done wrong, and to change. His “inspection,” as Sheila realizes in Act Three, is designed to encourage them to interrogate themselves, to consider when in their lives they have behaved immorally, and how they might improve as family members, friends, and citizens.