The inspector is affirmative when propagating (spreading) responsibility.
The Inspector is not subtle in his description of Eva's suicide and is affirmative and confrontational in addressing their abandonment of morals.
The Inspector speaks [sternly to both of them] when addressing Sheila and Gerald.
He does not allow Sheila's docile (submissive) expectations as a woman, nor Gerald's untouchable higher status, to prohibit him from harshly delivering the message of responsibility.
In society, both would typically be exempt from serious responsibility for these reasons.
The Inspector's stage directions are indicative of his power and affirmative nature which is clear throughout Act 2 when he:
[cutting in, with authority] when Mr. Birling speaks.
[with authority] when speaking to Gerald.
[severely] speaking to Mrs. Birling.
The inspector's intolerant and brutal demeanour is used by Priestley to ironically show how it is the upper and middle-class members of society who require;
"to come down harshly on these people" (Mr. B Act 1)
Their wilful ignorance and oblivion can only be shattered by forcing them to face the bleakness of reality.
The Inspector is used to examine each character's intrinsic morality and innate sense of guilt.
He exposes, throughout his ceaseless (unending) investigation, that how indoctrinated an individual is by capitalism is synonymous with how resistant they are to change and lacking morality and guilt.
This is highlighted through Mr. Birling, Mrs. Birling, and Gerald.
Gerald's narrow world views are engrained into him, not allowing him to develop this intrinsic sense of morality as he is deeply grounded in the upper echelon (level/rank, profession).
Mrs. Birling is defensive and opposing towards the Inspector, she is insulted that the Inspector is examining her intrinsic morals when he questions her lying:
"I beg your pardon!"
The exclamatory sentence reinforces how Mrs. Birling is astounded that her morality and guilt are questioned as these are two ideas in her warped view of life, that can be overcome with money and materialistic items.
Priestly cleverly crafts the capitalists to remain stagnant and obstinate to reveal how socialism catalyses a change in both people and society.
Contrastingly, capitalism only prohibits revolutionary change and reform as they believe that change is tantamount (the same as) a loss of their power.
Despite Mr. Birling physically being distressed by the Inspectors investigation as he becomes;
[rather hot, bothered]
He proceeds to try and be ignorant of his family's unscrupulousness (no morals), still indoctrinated by the capitalist idea that his 'public image' is more integral than his morality.