Allegorical drama popular in Europe during the 15th and 16th centuries in which the characters personified moral qualities such as charity or vice or abstractions as death or youth, and moral lessons are taught
Priestley inverts the detective fiction genre to make the point that society as a whole is guilty of neglecting and abusing its most vulnerable members
The overarching message that J.B. Priestley wants the audience to take from the play is that we are members of one body and are responsible for each other
The dramatic irony, such as Birling's claim that the Titanic is "unsinkable, absolutely unsinkable", underlines the fact that An Inspector Calls is a play with a moral message that needs to be hammered home clearly
The way Birling speaks to the maid, Edna, highlights the class dynamics in the play, with Birling using blunt, monosyllabic commands that suggest no attempt at politeness or respect
Birling's offhand comments about Edna waiting up late without choice or recompense subtly add to the dramatic force of the play's exploration of unfair working conditions for the working class