How does is the theme of remorse presented in 'An Inspector Calls'?

In 'An Inspector Calls', J B Priestly explores the theme of remorse in many different ways. Through the characters of Mr and Mrs Birling, Priestly illustrates how privilege and prejudice from the older generation can cause a lack of remorse, thus warning his audience against this. In contrast, Sheila and Eric show deep remorse and regret for how they have acted and their part to play in Eva Smith's death, with Gerald resting somewhere in between these two pairs. In terms of the ages of these characters and Priestly's backdrop of rebuilding society after World War two, it is clear that Priestly uses the theme of remorse as part of the overruling moral of this play, to warn the audience against making mistakes of the past.