Each character is punished in an appropriate way. Birling fears for his family’s reputation at the inquest; Sheila feels shame for her selfishness; Gerald has his affair revealed in front of Sheila; Mrs Birling has her illusions about the respectability of her family shattered by Eric; and Eric is revealed before his indulgent parents as a spoilt and inadequate young man. In each case, however the punishment is a consequence of their own behaviour; the Inspector himself does not bring punishment from outside.
This may be why they are given a second chance at the end of the play – that their experience should have been a warning to them, and that next time, it is the prediction in the Inspector’s final speech that lies in store for them and for the audience: “Fire, blood and anguish.” Priestley’s audience would have the benefit of hindsight and would know of the years to follow. This heightens the mystery surrounding the inspector. He represents the future, and is the Birlings chance of repentance, but only Eric and Sheila actually realise this. They must decide whether to change or not – Sheila and Eric, being young and still impressionable, do, realising the mistakes of the previous generations. The Birlings and Gerald, being set in their ways and having a distrustful short-sighted disposition, do not.
Throughout the play the Inspector demonstrates how people are responsible for how they affect the lives of others; his views are summed up in his dramatic final speech: that ‘we are members of one body. We are responsible for each other’. Responsibility is one of the play’s key themes, and the Inspector is Priestley’s vehicle for putting across his own views of this as a socialist. In this final speech, he is speaking as much to the audience as to the characters on stage. His words here are a warning to future generations not to repeat the selfish mistakes that led to the ‘fire and blood and anguish’ of two World Wars and the depression of capitalism in the years between them.
The Inspector is the medium for the events of the play: without his intervention, none of the characters’ secrets would have been revealed. Mr Birling could not see that he did anything wrong in sacking a troublemaker; Sheila thought her rather spiteful jealousy of a pretty shop-assistant was not ‘anything very terrible at the time’; Gerald needed to conceal his involvement with the girl to protect his own interests; Mrs Birling is too cold ever to ‘have known what the girl was feeling’, whilst the effect seems lost on her; and Eric had resorted to theft, which he also needed to conceal. Without the Inspector’s ‘purposefulness’, each character could not or would not have acknowledged their behaviour.
Priestley is trying to rouse the audience into taking a long, hard, critical look at themselves, – money and power are supposed to be a privilege – not a weapon to make yourself look big. He is saying that there should be more equality and we shouldn’t take our lifestyles for granted. We should also take responsibility for our actions or we could end up in an awful situation, just as the Birlings and Gerald did when they received the phone call at the end of the play to say an inspector was on his way round. Priestley is trying to convert people by using this play as a socialist piece of propaganda – only showing the necessary parts of the story to create the desired effect.
Priestley wants the Inspector to dominate the audience. At the time the drama was conceived World War II had scarred society and European minds. The play was a moralistic mystery that made the audience think. The Inspector himself is used as a dramatic device in that the play gives you time to change your actions towards others, that is before “An Inspector calls” on you, to teach you in ‘blood and fire and in anguish.’