Explain a key theme of J.B Priestley's An Inspector Calls. Give context where appropriate.

Prietsley's An Inspector Calls serves as a mouthpiece for Priestly himself. The themes of socialism and social responsibility is displayed by the domino effect that each member of the Birling family has on Eva Smith, eventually leading to her suicide. Each character treats Eva Smith in a selfish, unthoughtful, and cruel way, i.e Mrs Birling refusing her support from a women's commitee due to her "impertinence".
Priestley uses the character of Inspector Goole as a platform to voice his own views on social responsibility and subsequently, socialism. Set in 1912 against the oncoming First World War and sinking of the Titanic, Socialism and social responsibility began to gain traction shortly after thanks to the mass return of soldiers suffering with PTSD, and the break down of the social classes. Priestly uses the Birling family as an microcosm for the rest of the general population, using the youth, Sheila and Eric, to propose an acceptance of social change, whilst displaying the old, Mr and Mrs Birling, as clueless and unwilling to adapt.