The noun 'duty' could be a tool to explore the disparity between capitalists and socialists. For capitalists, upholding the class system was paramount, thus, for Mrs Birling, her duty and personal responsibility may be to uphold the class gap by refusing Eva help. However, this stance contrasts sharply with her anticipated role within her organisation, where she is expected to adopt a philanthropic position. Priestley introduces the audience to the social duty vs moral duty dichotomy.